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The Craftmans Shop => New from Old => Topic started by: awemawson on February 05, 2018, 02:46:12 PM

Title: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 05, 2018, 02:46:12 PM
Today my friend Derek and I left Sedlescombe in East Sussex at 06:00 in quite heavy flurries of snow heading off to Somerset to collect my newly acquired pile of scrap that once had been a Denford MIRAC CNC Lathe. Due to the snow, morning rush hour on the M25 and hold ups on the M3 we eventually arrived at Stoke St Michael 170 miles and four hours later catching the vendor still in bed  :clap:

Now I hadn't been confident in the measurements he'd given me for either the lathe or it's stand despite his assurances, and sure enough either his tape had shrunk or the machine had grown - it was extremely tight getting it in the van. And again despite his assurance that the stand would fit over the machine there was absolutely no way it would  :bang:

So having shoehorned the lathe into the van I got Mr Stay In Bed to take an angle grinder to the stand and put it in in pieces reasoning that I could make good the damage with the welder  :ddb:

Journey back was a breeze by comparison, and even stopping for a light lunch we were back ready to unload by 15:00

A quick cup of coffee, feed the pigs then unloaded by forklift (once the propane gasifier had unfrozen  :bang:)

So a quick examination found that it was a model of MIRAC that I've not seen before, with a Viglen Genie PC slotted into the drive box apparently as original equipment, with a bespoke inverter drive for the spindle complete with brake unit, a small Mitsubishi inverter for the tool turret that looks like a replacement for (perhaps) another bespoke one, and custom power supply and two axis drive board.

Tomorrow I will start a clean up, remove all the swarf and oil from the base and try and get it up onto a pump up trolley for better access and investigation.

Probably I'll try and get the original PC drive working but I very much doubt I will keep it. Currently I have my eye on the Centroid Acorn offering:

http://www.centroidcnc.com/centroid_diy/acorn_cnc_controller.html

Cheap it ain't once landed in the UK with Shipping, VAT and customs charges, but it seems a very capable controller that ticks most of the boxes.


Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: DICKEYBIRD on February 05, 2018, 06:17:50 PM
Very nice Andrew, it even came pre-swarfed!  That's going to be a great machine when you finish with it.  I like my little ORAC but being based on the Compact 8 design is only 8" swing.  The Mirac's bigger I'm sure.  About 10" I think.  Have you looked at what size stock it'll take "up the snout?"  The ORAC's only 20mm.  Sure wish it would do about 25.

Can't wait to watch you do you thing!  :clap:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: tom osselton on February 06, 2018, 01:42:22 AM
Should be another interesting project! I'll pop some corn!
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: Meldonmech on February 06, 2018, 04:33:35 AM
Hi Andrew

               Looking good, new it would'nt be long before you embarked on another big project to keep you amused.

                                       Good Luck
                                                          Cheers David
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: Will_D on February 06, 2018, 06:24:04 AM
You are an inspiration Andrew.

Following your projects is what gives me the Kick-up-the_ar*e I need to keep plodding on.

Looking forward to this.

I also looked at the Acorn controller for my little Sieg X2P CNCconversion.

Cheers

Will
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 06, 2018, 07:48:29 AM
Thanks chaps  :thumbup:

This mornings job was to glue the trolley base back together having had to cut it apart to fit in the van.

Turns out not only were three of the castors missing their tyres, but they were welded on. So - cut off old castors - do a bit of weld preparation  - weld the frame back together overcoming the inevitable springing out of alignment with some innovative clamping - then drill and tap for replacement castors.

.... what could be simpler  :ddb:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: DICKEYBIRD on February 06, 2018, 09:30:58 AM
Might I suggest to the master titivator the addition of a couple or 3 geodesic braces to the base? :bow: :beer:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: PekkaNF on February 06, 2018, 09:45:50 AM
Loosely...396,49 € tax incl.

http://makersupplies.dk/motion-controllers/312-acorn-4-axis-motion-control-w-free-pc-software.html

Don't know that shop, I was looking for a stepper motor with 8 mm shaft and remembered this thread. Would this be cheaper from EU?

Pekka
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 06, 2018, 12:52:39 PM
So the afternoons task - put it back on the trolley and start the clean up. Just a rough first pass to get the bigger clods out !
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: krv3000 on February 06, 2018, 04:19:55 PM
a job well dun I need a stand making for me mill
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: David Jupp on February 07, 2018, 08:31:13 AM
Andrew - I presume you've already found the information on the Mirac on the Denford forum.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 07, 2018, 09:29:57 AM
David I have and I haven't - I cannot identify the exact machine nor can I find a suitable circuit diagram - there seems to be a myriad of Mirac models  :bang:

This one has an LCB3 control board but seems to differ from ones on Denfords site - they share one invertor for the spindle drive and the tool turret motor for example whereas this one has one dedicated to the spindle and another for the turret. Also I've not yet found one where the PC is slotted into the side of the machine.

A bit of progress today. I decided to see if I could get the original controller to work, so blew a century of muck out of the keyboard and monitor and plugged it all together. After checking for no stray wires I plugged it in and was AMAZED to find it booted up after what must have been a decade of sleeping  :clap:

The various Mirac screens can be brought up but at the moment I can't move any axis or spin any motors other than the coolant pump as I cannot get it out of eStop. I need to 'knife and fork' my way through the eStop chain - I've done a bit but I need to go and prepare supper as we have guests this evening.

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: Pete. on February 07, 2018, 01:54:37 PM
That's a surprise. I would expect to be getting all sorts of BIOS errors. Very encouraging Andrew.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 07, 2018, 06:49:06 PM
Yes I  was rather taken aback  :clap:

The PC must have been changed at some time as there are socket converters in line with the keyboard from PS2 to DIN and 25 way to 9 way on the serial port. it looks like the PC sends commands to the Denford LCB3 card over the serial port as the parallel port on the PC is unused.

I suspect that if I can overcome this eStop issue the controller might actually work. I'm tempted as a diagnostic aid to hard wire the eStop relay permanently 'on' for testing purposes. Then if the controller drives the axis and spindle it's worth spending time to bottom the issue.

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: Pete. on February 08, 2018, 02:08:23 AM
If you need to replace any door/safety/limit switches I have a box full of nice Telemechanique limit switches I salvaged off a machine. Fully IP resistant and with one NC/one NO contact in each.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 08, 2018, 09:35:31 AM
So I took my courage in both hands and 'wired out' the Emergency Stop circuit, feeding 24v directly to the ES Relay and lo and behold everything sprang into life :clap:

We now have power to the axis drives and spindle motors and can home and jog etc  :ddb:

Had to do a dummy trial using one of the programs resident on the original PC  hard drive but first I had to work out how work and tool offset are stored - turns out they are in a common file on the HDD:





Having proved it now works it was a case of slogging through the Stop chain to find the fault, which turned out to be a voltage sensing relay that looks at a thermistor buried in the tool post turret motor. Although it's input was OK it's contacts were permanently open circuit. I've linked it out of the chain for the moment.


Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: philf on February 08, 2018, 09:43:14 AM
Andrew,

Looking good  :thumbup: although the tool changer sounds as though it needs some grease. (Unless they always sound like that.)

I hope you're going to backup the hard drive before you do anything else!

Phil.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: mattinker on February 08, 2018, 10:38:55 AM
I'm glad to see it works, bit too easy though!!

Regards, Matthew
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 08, 2018, 10:51:22 AM
Thanks chaps - yes the gears or motor on the turret sound horrid - probably never been greased !

So the voltage sensitive relay - what to do ?

I could leave it wired out, and ignore the turret thermistor . . . .but that graunching sound . . .  :thumbup:

I could buy another one, except that RS part 346-154 is now obsolete, and new equivalents are not only very expensive but also not an 11 pin base so physically different.

So nothing to loose I pulled the old one apart and having put my electronics head on started poking about for a look see. 110v AC comes in to a transformer followed by a four diode bridge with a filter capacitor across the input and a 100 mFd 40v electrolytic as a reservoir - pretty standard. Start testing the diodes and they all read 700 ohms BOTH WAYS - something wrong here, they should be that one polarity only ! Quck test of the capacitor in circuit - dead short  :thumbup:

Whip the capacitor out, test the diodes, all is well this time. Pop a replacement 100 mFd capacitor in (35v working but it'll be fine) and do a quick test in circuit before replacing the cover. Well how about that - it works  :ddb:

Pop the cover on, take out the link I'd put across it's contacts and it all seems to work - the tweaker gives a reasonable range and at one extreme the Emergency Stop Relay drops out just as it should. Well that saved a bob or two !

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: DICKEYBIRD on February 08, 2018, 11:37:46 AM
Feels great getting making an old soldier healthy again doesn't it? :clap:

I have a Denford MicroMill and those chaps up in sunny Brighouse make a very solid machine .  Mine's a training machine & has a puny little Sherline mill but the control is robust.  I was going to use the original software as well but the lack of the magic dongle made that effort futile.  I snatched off Denfords proprietary serial board & hacked straight into the SmartStep board with step/dir signals from Mach & a parallel port.

In searches on their site I found that they offer the old DOS software for free download, or used to anyway.  There's nothing wrong with DOS & it probably works reliably without the influence of Windoze.  As long as it will recognize the encoder, threading should be fine.  I wonder if it came with any conversational programs or any CAM functions?

Gotta luv your :beer: projects!
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: tom osselton on February 08, 2018, 03:00:05 PM
That was way too easy! But you deserve a break after that last one you did well done!
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 08, 2018, 04:12:17 PM
Andrew,

Looking good  :thumbup: although the tool changer sounds as though it needs some grease. (Unless they always sound like that.)

I hope you're going to backup the hard drive before you do anything else!

Phil.

Phil, Just finished a full disk back up. Thirteen 1.44  floppies under MSBACKUP under DOS 6.22 - no easy other way to do it. I may try and fit a CD drive now I have a backup but it's a bit of a rigmarole loading the extra drivers as I don't think DOS 6.22 had CD support
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: philf on February 08, 2018, 04:58:04 PM
Andrew,

I was thinking rather of lifting the drive out and cloning it. I did that for my Mach3 PC after the length of time it took me to configure the PC and Mach3 - I didn't want to start from scratch again.

I'm surprised anyone still has floppies!

Anyway, better safe than sorry.

Phil.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 08, 2018, 05:20:59 PM
My approach was to get the data off before poking about and the PC possibly dying  :bugeye:

As I was hunting for floppies I discovered that I had a set of DOS 6.22 original install disks tucked away !
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: DICKEYBIRD on February 08, 2018, 06:27:56 PM
Andrew, one of the fellows on another forum reported success with a floppy/USB adapter with DOS.  He was saying that it's somewhat popular with old CNC machine users to get away from the hazards of floppy usage.  I'm sure we've all lost important data using those %$^%& things!
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 09, 2018, 02:27:18 AM
Interesting Milton.. Is that a 'floppy to usb stick' adapter Milton or what? Have you a link to the reference?
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: seadog on February 09, 2018, 05:24:49 AM
I think this is what is being referred to, Andrew.

http://www.ebay.co.uk/bhp/floppy-to-usb
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 09, 2018, 05:35:55 AM
Thanks for the link Seadog  :thumbup:

So this morning I actually made parts with the lathe :ddb: This bit is I presume supposed to be a countersunk rivet - it's made using the program running on the Youtube video I put up in a previous post - two in brass and one in steel. Watching it I reckon the feeds and speeds were intended for brass as although the steel part has a very good finish I cringed a bit as it was cutting !
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: seadog on February 09, 2018, 05:56:16 AM
I'm a little disappointed with that. The last CNC rebuild you did was such a tour de force. I was getting ready to enjoy the follow up, but it only needs a coat of paint  :D
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: DICKEYBIRD on February 09, 2018, 10:04:56 AM
Interesting Milton.. Is that a 'floppy to usb stick' adapter Milton or what? Have you a link to the reference?
Couldn't find the thread I was thinking of but you've probably already found one but here's one that looks just like I remember...sorta.

https://www.amazon.com/Floppy-Emulator-WireCut-Brother-machine/dp/B01N4ILYEG/ref=sr_1_1_sspa?ie=UTF8&qid=1518188365&sr=8-1-spons&keywords=usb+floppy+emulator&psc=1

ps: Set that parting tool on center!;)
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 10, 2018, 02:56:06 PM
Well today after a lot of faffing about I've cloned the PC that came with the MIRAC onto a Compac DC7600 SFF (small form factor) that I had kicking about. I chose one off the pile that already had the correct moulded front panel incorporating a floppy as well as as a CD/DVD player and loaded it up with DOS 6.22 as I had the original installation disks.

The PC that came with the MIRAC (a Viglen Genie) was running DOS 6.2 and it turns out that MSBACKUP in DOS 6.22 cannot restore disks created under DOS 6.2 without a different compression algorithm (DBLSPACE) being loaded  as a system device - fortunately I found a copy and it worked  :ddb:

Now I just need to sort out a second serial port on this PC :ddb: - it uses one to talk to the operator panel keyboard and one for the LCB3 CNC driver board. Needs to be a low profile PCI card and i think I've sourced one on eBay arriving Thursday.

The power interlock for the electronics cabinet has been smashed - long square shaft from DIN rail isolator at the back of the cabinet should engage a door mounted handle, and has obviously been slammed shut a few times out of alignment smashing the external activator beyond repair - one on order should arrive Monday.

The open slot trunking in this cabinet is missing much of it's capping cover - again some should arrive Monday

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: DICKEYBIRD on February 10, 2018, 05:20:56 PM
I'm really liking this Andrew!  Just think of the pi$$ you can take out of the Windoze & Linux crowd.  No ethernets,  internets or clouds needed with this machine.  Ahh, the memories! :thumbup:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 11, 2018, 03:10:59 AM
Glad you are still there for the ride, Milton  :thumbup:

Today's task: work out how to get MSDOS 6.22 to talk to a CD/DVD drive, and get a floppy installed into one of my other PCs to transfer files Internet > Other PC > Floppy > COMPAC DC7600, as the various CD drivers need sucking off the net and currently the only means of input to the DC7600 is floppy.

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 12, 2018, 07:17:05 AM
Haven't got the CD talking to DOS 6.22 yet, but have a special CD & Mouse extension program arriving later in the week.

This morning Adrian the Parcel Force man delivered the new panel isolator switch from RS Components - though I sent him into a flurry when I told him there was supposed to be a second parcel with the trunking capping in it - probably come tomorrow.

Assembling the DIN rail isolator on the bench it was obvious that the extension rod and its fittings weren't quite right - one female plastic socket thingy had a pair of projections preventing the male sliding in. A quick call to their help desk revealed it was the wrong extension despite being referenced in the isolator illustration  :bang: Solution - another £25 for a different isolator OR a bit of vertical paring with a small wood chisel - I'll let you guess which I did  :lol:

As the rear panel on this machine is double skin and this switch assembly requires more hardware on the door than the previous one, I had to do a bit of butchery and cut a square hole for an escutcheon, then get it all lined up and the shaft cut to length. Got there in the end  :thumbup:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: David Jupp on February 12, 2018, 10:34:28 AM
RS are sometimes a bit careless with the illustrations - often just a generic image rather than the actual part number you have called up.  If the data sheet isn't clear it can be pot luck what you end up ordering.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 13, 2018, 07:12:09 AM
The trunking got delivered this morning, so I was able to steal it's capping and make good the missing bits that have been lost over the years.

One step forwards and two back as far as the replacement PC is concerned. The "automatic add CD support CD" arrived and the end result is an un-bootable system with a CD drive appearing as R: and as a network drive  :bang:

I have ways back to where I was but it's a pain. I'll probably re-partition the drive before I re-do it as it's far bigger than DOS can handle anyway.

The extra serial port card has arrived but I can't do anything with that until the PC will at least boot.

A nice man at Baruffaldi has sent me a PDF of the turret manual - 6 MB so too large to attach - in Italian of course but it's mostly drawings none of which seem to offer any means of adding lubrication  :scratch:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: David Jupp on February 13, 2018, 07:37:24 AM
Andrew - English manual for the turret

http://www.denfordata.com/bb/download/file.php?id=2694 (http://www.denfordata.com/bb/download/file.php?id=2694)

Not sure if you have to be logged in to get the file.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: Will_D on February 13, 2018, 08:50:49 AM
Not sure if you have to be logged in to get the file.
Nope. Downloaded straight away!
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 13, 2018, 10:29:44 AM
David thank you but that is the TOE turret not the RH80.

Just re-partitioned the HDD in the target DC7600 SFF PC, formatted it, loaded DOS 6.22 from original Microsoft floppies, loaded the DOS 6.2 version (*) of MSBACKUP into it's own directory and restored 13 floppies to bring the MIRAC original PC's software onto the new one.

I'll now manually update the autoexec.bat and config.sys to get the CD drive online hopefully.


(* MSBACKUP 6.22 will not recognize backups performed under DOS 6.2  :bang: )
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: Will_D on February 13, 2018, 05:11:43 PM
All these skills and you can even make bacon!!
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: David Jupp on February 14, 2018, 12:14:22 PM
Andrew - Spares price list (vintage 1990) from UK distributor for the RH80
 http://www.denfordata.com/bb/download/file.php?id=1120 (http://www.denfordata.com/bb/download/file.php?id=1120)

Not sure if it is any use to you.

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 14, 2018, 12:35:12 PM
Thanks David - already downloaded - massive prices aren't they  :bugeye:

So a bit of progress. After advice given by 'Tim' on the UK DIY  newsgroup (remember newsgroups !!!) I have loaded LINUX-MINT-MATE onto a USB stick and successfully booted from it on the target PC that is going into the lathe. Then again successfully connected it to my home network and copied files onto my desktop PC.

The USB stick is painfully slow to load but it works  :ddb:

Now need to see if there is some Linux software to burn CD's that I can load onto the stick and if so I probably have all bases covered. The USB stick is a USB-2 Cruzer Blade Flash Drive - 16 GB. I don't think that the PC will do USB-3 to speed things up but there is probably a newer faster stick out there as I've had this one a few years now  :coffee:

Odd seeing a Mint UNIX screen in the workshop - not my native operating system that's for sure  :scratch:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 14, 2018, 03:28:46 PM
So a bit more progress. I've loaded Kb3 cd/dvd writer to the USB stick, and generated a CD copy of the current target PC hard drive, which I can read spiffingly under WIN7 on my desktop PC - oddly under DOS on the target PC it has difficulty reading despite being in the drive it was written in  :scratch:

However the written CD reads fine under MINT in the target PC - presumably different drivers under DOS and UNIX so another issue to bottom out.


Bit complicated these compatibility issues on operating systems  :bang:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 14, 2018, 05:32:09 PM
Elsewhere I've been asked why and how did I clone the original Viglen PC - as I wrote it up for them I thought I'd paste it in here as well:

A/ The original Viglen is fully functional but mechanically a write off

B/ The Viglen runs DOS 6.2 and has a floppy drive and HDD and two serial
ports

C/ One serial port is for an operators panel, the other is for the machine
CNC controller

D/ I took an MSBACKUP of the VIGLEN HDD under DOS6.2 on 13 floppies

E/ The COMPAC DC7600 SFF was running Windows 7 and has floppy, SATA HDD and
CD/DVD writer, one serial port and a network 10/100 port and 4 Gb RAM

F/ I Repartitioned and formatted its HDD and loaded DOS 6.22 from the three
original Microsoft disks

G/ I copied the full DOS 6.2 MSBACKUP suite to a folder on the DC7600

H/ I ran DOS 6.2 MSBACKUP under DOS 6.22 and restored all the VIGLEN files
to the DC7600 EXCEPT the DOS folder

I/ (You need to know the MSBACKUP 6.22 cannot read MSBACKUP 6.2 floppies)

J/ At this stage I had a fully functional DC7600 running DOS 6.22 and the
original controller software from the VIGLEN (except it only had one serial
port)

K/ Being an SFF I needed a small form factor PCI serial card - the only one
I could source with DOS drivers was a StarTech PEX2S5521P

L/ The machine now has three serial ports and I just need to configure the
IRQ to match the original

M/ I sourced some DOS drivers for the CR/DVD which allowed me to read but
not write CDs

N/ This is when I posted asking for assistance for DOS software to WRITE CDs
so that the machine files can easily be transferred in future

O/ I have (Thanks to TIM) loaded a USB stick with Linux MINT and K3B CD
software allowing me not only to boot up MINT and generate CD's but also
connect to my network and transfer files that way !!!

P/ The only oddity left is that the CDs generated read properly under MINT
in the DC7600 and also und WIN7 on another machine but under DOS 6.22 in the
DC7600 are rather flaky and rarely read ok.

Q/ I am assuming this is due to the DOS drivers I'm using (can't name them
at the moment as I'm on a different PC)



Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: Pete. on February 18, 2018, 03:27:30 PM
Did you order the Acorn controller Andrew, or are you holding off to see what the original controller works like?

This guy seems to be having some trouble getting his order in:

http://bbs.homeshopmachinist.net/threads/75744-Any-news-on-the-Acorn-CNC-board
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 18, 2018, 04:56:48 PM
I was all set to order not only the controller, but also the pre-loaded PC with Win10 and touch screen monitor. Couldn't find a spec on their web site for it. Couldn't ask a question on the forum as not yet a customer so couldn't register  :bang: So I sent an email and even now three weeks later haven't had a reply. So no, not bought the Acorn controller !

Meanwhile I have the original controller working quite nicely thank you and am working on replacing the internal PC and re-learning all I've forgotten about Dos 6.22  :lol:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: DICKEYBIRD on February 18, 2018, 09:10:57 PM
Couldn't ask a question on the forum as not yet a customer so couldn't register
WOW!  I'm completely flabbergasted by that Andrew.  There's a forum member that continually whinged about Acorn not doing this or that that he thought it should do who hasn't even purchased one so I can't fathom why someone like you has been denied registration.  Maybe the Centroid staff got tired of defending their product from non-owner back biters & now refuse admission unless one buys one...wko knows???  I do know that they've now sold a bunch of them & the support volume has increased.  They are a dedicated bunch of folks and work very hard to respond to their customers' questions.  I'm positive that a person such as yourself would be a welcome addition to the group, Acorn owner or not.

If there's something you need an answer to I'd be happy to ask it for you although it looks like you've just about made the original system your slave & may not want spend the money on a new control yet. 
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 19, 2018, 02:52:48 AM
The registration form requires, iirc, a product number / serial number and if not completed you cannot proceed.  :bang:

I wanted to know basic things about the PC such as how much memory, what sort of disk drive etc and also dimensions of it and the touch monitor along with mounting details. Basic details to see if it would fit ! I'd have expected such detail to be on their web site but couldn't find it so asked if it was there somewhere

But no reply so no purchase  :scratch:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: DICKEYBIRD on February 19, 2018, 08:20:40 AM
The registration form requires, iirc, a product number / serial number and if not completed you cannot proceed.
Unless they've changed, it only asks for numbers so support can see exactly what they're dealing with if there's a product problem/question.  AFAIK they don't exclude prospective customers from the forum.  They have always answered questions from everyone since I've been there, owner  or not.  They did ban one particularly unpleasant fellow that fancied himself the know-all grand poobah/big kahuna of the internet CNC world that constantly dissed them & their product.  He deserved being banned.

Try again if you're still interested...your participation would be great whether you end up buying one or not. :thumbup:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: DICKEYBIRD on February 19, 2018, 09:51:25 AM
I wanted to know basic things about the PC such as how much memory, what sort of disk drive etc and also dimensions of it and the touch monitor along with mounting details. Basic details to see if it would fit!
The one they sell on the Centroid site is an Intel NUC which is 4"x4" (100x100mm) so you'd have room left for your lunch pail & a thermos.  The monitor they sell is a 19.5".  You can use any size monitor you want (touchscreen or not) as long as it is a 16:9 AR (or have that AR display resolution available).  As to PC req. anything that runs W10 will be fine as long as the single core minimum benchmark is at least 1500, Ethernet available & has 4 GB RAM.  They recommend an SSD but to me that would be nice but is a bit of overkill.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 19, 2018, 10:28:10 AM
They advertise their part #12786 which doesn't say it is an NUC and they advertise #14366 which IS an NUC. It was #12786 complete with monitor I was after at $799 but wanted a spec first as none is shown. For that sort of money I want to know what I am buying !

I see they have changed the registration form now to accept 'none' as to which item you own - too late, they lost a sale and I saved a lot of money !

Still had no reply to my email which is rude to my way of thinking
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 25, 2018, 04:34:28 AM
So at long last I've managed to install a second serial port into the Compac DC7600 SFF PC that will be embedded into the MIRAC.  :ddb:

I traced the correct Compac part  PA716A which despite appearances is NOT just an external socket and a ribbon cable, but has active components, and plugs into what appears to be a socket on the motherboard carrying a subset of the PCI bus.

I had previously tried PCI express serial cards but could not get them to map to the correct address and interrupt lines for the MIRAC software to use, however the  PA716A  plugged straight in, appeared in the BIOS at boot and was already on the correct address and interrupt  :thumbup:

So this mornings job was to lash in the new DC7600 SFF PC to prove things work before hacking the old Viglen out. Glad to say all went well and I've successfully turned  parts this morning just as before.

I now need to check airflow direction to ensure that the PC fan and the cabinet enclosure fan aren't fighting each other, then I can plan how to mount up the DC7600 SFF
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on February 25, 2018, 05:07:36 AM
A quick test with a smouldering paper proved that the original cabinet fan, and the airflow through the PC will tend to pressurise the cabinet. This is correct design as it tends to keep stuff out of the cabinet unless its been through the filters.

However there seems to be no designed exit for the air. Apart from a cable duct passing into the machining space - no exit  :scratch:

. . . Need to think about this and possibly adding one  :coffee:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 05, 2018, 04:00:56 PM
Time for a bit of an update:

The replacement PC is now mounted in the enclosure with suitable metal work to suspend it in place and present a fair face to the outside world by way of an escutcheon plate.

I've made and fitted a replacement for the headstock end panel keeping fingers out of belts  :bugeye:

I've made a replacement for the lubrication pump access door

All await painting, but that will be done when the entire machine enclosure can be dismounted and sand blasted

The machine is working well and I've today been experimenting with the G76 threading cycle. The machine obeys the Fanuc dialect of G code and the G76 command (which occupies two lines of code) is one of the more complex ones with loads of parameters to tweak.

Net result: today I've made some of the most expensive and time consuming M6 brass hex bolts ever  :lol:

Please excuse the swarf on the pictures of the bolt  :palm:

The sliding front cover / door is obviously not the original, and whoever started making this one made a reasonable job of it but never finished, so there is no provision for a lower slider. I've various bits on order to make not only the slider arrangement but also to insert a better sized window (in 6 mm polycarbonate)

(I've a video uploading to Youtube that I'll link in when it's finished)
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: tom osselton on March 05, 2018, 04:53:58 PM
 This is coming along nicely!  I wish I could say the same about mine!
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 06, 2018, 03:14:04 AM
Here is the promised video:

Making the most expensive brass M6 hex bolt ever :lol:

It was as you probably realise, a learning exercise particularly with the G76 Fanuc G code, which is a bit complicated. Note that I use the parting tool at the end to chamfer the head of the bolt before final parting off.




You'll notice that there are significant pauses before the actual G76 lines are processed - I'm assuming that the controller is doing a fair amount of calculation - remember that the controller is running under DOS although it's got a pretty fast CPU to use compared to what it would have originally been equipped with.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: seadog on March 06, 2018, 07:28:04 AM
I see the need for a pneumatic chuck with bar feed  :D
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: tom osselton on March 06, 2018, 04:21:04 PM
It seems to do a nice job of it! :clap:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 06, 2018, 04:23:09 PM
Thanks Tom  :thumbup:

Seadog, a pneumatic chuck was an available option when these were made - sadly I don't have one

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 07, 2018, 04:30:00 PM
Late in the afternoon a courier delivered a 500 mm square by 6 mm poly carbonate sheet to make the new window.

I hate cutting things like this as you only have one chance - anyway after supper and a can of Old Speckled Hen I took my courage in both hands, cleaned off the band saw table and had at it.

Didn't go too badly actually. I then finessed it on the disk sander as I'd been a bit cautious cutting the radii, so I took it 'back to the line.

Tomorrow I must face the task of cutting a similar shape in the door, but slightly over size to allow for the rubber window seal. I suspect a loosish fit is what to aim for, as fitting those rubber seals can be entertaining  :clap:

. . but that's tomorrow and I have a batch of pigs going off so that may delay things . . . . :med:

(ps window looks opaque as protective film is still on it)
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 08, 2018, 10:14:09 AM
No good putting it off any more - time to cut out the metal 'hole' for the window.

The window rubber takes up a significant space, so the opening needed to be larger than the polycarbonate by 9 mm all round. So that I could 'draw round'  the already cut window, I turned up an 18 mm diameter 'washer' from a bit of tufnol I had lying around, and put a 4 mm hole in the middle to take a Sharpie pen.

Overall the rubber is about 25 mm wide, so I moved the window position slightly so as not to foul the  upper slider channel.

I cut the straight bits using a 1 mm cutting disk in my angle grinder, and cut the radiused corners using my jig saw. Seems to have come out OK but the real proof is when the glazing is fitted and held in by the rubber. Once the rubber and glazing are in place there is a 'filler strip' that holds the rubber tight - hopefully I've left enough allowance to get the glazing in, but not so much to let it fall out again  :med:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 08, 2018, 10:28:49 AM
Putting the cover temporarily on the machine the opening 'looks right' but I'm going to have to sort out the brush seal - probably replace it with one with longer bristles mounted further back to give more flexibility.

I don't want to mount the rubber and glazing until the cover is painted, as I suspect once they are fitted they'd be the devil of a job to get off again without damaging them.

The glazing rubber obviously has a slot for the 'glass', a slot for the metal frame, but it also has a strange shape moulded in to take an infill trim that is not just decorative but serves to tighten the grip of the rubber on the other components. It uses a special tool to insert in - fortunately this is the same rubber profile that I used on my Traub lathe so I already had the tool  :thumbup:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 08, 2018, 10:43:59 AM
While I was doing all this, the postman kindly brought me a block of Delrin that I will be fashioning into a lower slider to take the weight of the cover.

First it needed slicing length ways on the band saw,  then cleaning up on the mill and a suitably placed channel milling for it to sit comfortably on the lower slide bar.

Undecided as yet whether to make it a short minimalist bit so that the door is effectively on three points (two up at the top)  or to keep it full length
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 11, 2018, 08:36:45 AM
I ended up fitting two short guide blocks, one at either end on the lower sliding rail.

Today's job: Make a little bracket to stop the sliding door lifting off it's rails. Simple in concept but very fiddly to decide how to form it and measure up for the making. Not only has it to function - it has to be possible to fit it !

Cut out a bit of 2 mm plate and hot bent it as 2 mm has a tendency to crack with tight bends. The bending went OK except I made one bend in the wrong place  :bang:

Never mind - get it cherry hot, flatten it out and put the bend in the right place - plonker !!!

Once bent roughly to shape I fitted it to the door off the lathe and tweaked things to fit - it works actually quite well  :ddb:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 11, 2018, 08:48:55 AM
So having made the lift stop all we need now is a handle on the door and I can get on painting it  :thumbup:

Two spacers of Delrin cut from a 25 mm black rod, a 25 mm x 4 mm x 310 mm  round edged bar and some M6 bolts cut to length and we have a handle. Pop a couple of holes in the door and bingo there we are  :ddb:

Now I've had problems with the Simonize satin black spray paint I've been using chipping off unless the metal has been sand blasted. OK I can sand blast the handle, but the door it too big for my cabinet blaster and the weather isn't conducive to using my big pot blaster. So I'm experimenting with a (new to me) paint intended for vehicle chassis work. Reputedly sticks to anything, doesn't need a primer, and minimal surface preparation.

Handle duly sprayed and awaiting final verdict when it's cured
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 11, 2018, 10:15:17 AM
Initial tests of the paint sample are very promising  :thumbup: After 90 minutes drying it passes the 'can I scratch it with my thumb nail test' which the Simonize failed miserably. Makers advise 24 hours for full cure.

So I've cleaned up the door and sprayed the inside with it's first coat. I'll give it another coat later today and leave it over night before turning it over and doing the outside.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: AdeV on March 11, 2018, 12:40:28 PM
You do realise of course that the shiny new door is going to make the rest of the machine look a bit shabby.... and in need of a paint job of it's own....?  :Doh: :lol:

Full strip-down to follow?  :poke: :ddb:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 11, 2018, 01:22:56 PM
Yes Ade, the cream coloured cover assembly would seem to lift off after about a million M4 button head screws have been removed. But I'm waiting for a bit of fine weather so that I can remove it, take it outside and grit blast it with my Hodge Clemco.

Meanwhile i'm trying to track down some very tough paint in that cream colour
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: hermetic on March 11, 2018, 03:31:01 PM
Hi Andrew, that glass rubber bead is very reminiscent of the original Austin mini screen seal, I have one of those bead fitting tools too!. We used to put the screen into the bead, put a loop of string into the gap where the metal would be,  place the whole lot over the hole, inserting the metal at one side and then pull the string inside the car, which lipped the rubber seal over the metal! Easy, especially with a bit of liquid soap or swarfega to lube the rubber. The inner lip that fits to the metal is far softer than the bit that holds the screen, and when the loop method fails, as it sometimes does, you can usually lip the rest of the rubber over with your fingers.
Phil.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 11, 2018, 03:48:44 PM
Hi Phil,

I just watched a YouTube video where they did just that  :thumbup:

I'm thinking of stretching the rubber around the window, cutting it exactly and supergluing it into a circle, so it will hold on and doing precisely as you describe  :clap:

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: vtsteam on March 11, 2018, 04:09:36 PM
Great project, Andrew, sorry I missed it earlier. I really admire your lathe. Perfect size -- to me at least.  :thumbup:

Until recently I used DOS based TurboCNC on a couple of machines I have -- a homemade hot wire foam cutter, and a gantry style router. So I'm enjoying the fact that you've restored a DOS CNC system on your newer computer.

Right now at work I'm attempting to bring back into operation a 1998 vintage MTI dicing saw purchased by the CEO at auction, reportedly for $250  :bugeye: . Multiple issues so far, but weeding through them, Andrew style!  :beer:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 11, 2018, 04:16:33 PM
Hi Steve, glad to have you along for the ride  :thumbup:

I'm re-learning things about DOS6.2 DOS6.22 WIN98 and XT that I forgot years back  :lol:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 11, 2018, 04:57:39 PM
OK I admit - I'm impatient  :lol:

This paint is pretty good stuff and dries quickly to a very tough finish. I've managed to give the door two coats both inside and outside, and also the coolant pump access door and the sliding door lift stop.

Mind you, at over £12 per 400 mL aerosol - and so far I've used well over one and a half - cheap it ain't  :bugeye:

However I'm very impressed with the finish and no doubt given a full 24 hours cure it's hardness can only improve (I hope !)

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: vintageandclassicrepairs on March 11, 2018, 05:48:41 PM
Hi Andrew,
There was a link to this company who will mix any colour machine paint you need on the Harrison Lathe forum recently
https://www.ebay.co.uk/itm/1-Litre-Harrison-Lathe-Beige-Engine-Enamel-Paint-High-Temp-/263107968126

Craftmaster Paints Ltd
Adam Brown
Acadamy Works
Norman Way Ind Est
Over
Cambridgeshire
CB24 5QE
United Kingdom

Enjoying the progress reports on the lathe
John
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 11, 2018, 05:58:37 PM
Thanks John, I've fired off a message to them  :thumbup:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 12, 2018, 10:13:33 AM
Today I attempted glazing the door and was defeated, deflated and a bit hacked off  :bang:

It was going quite well, I cut short samples from the length of window rubber and checked that my superglue satisfactorily bonded it back together - it did and had good tensile strength. (Incidentally the only way I could get a decent straight cut was with a micro-serrated knife stolen from the kitchen - a normal Stanley knife blade was too short to do it in one swipe)

I then tightly stretched the rubber around the glass, marked for cutting off, and deliberately cut it 15 mm too short so it had to be stretched on. Then I glued it using an off-cut of the polycarbonate sheet for alignment.

Then the fun started - now the rubber was glued into a continuous loop it had no desire whatsoever to stay around the window pane, get a bit on and another bit would run for freedom. Multiple hands needed - in fact the wife was called to contribute another pair and even then it was winning all the time. In the interests of marital harmony I resumed on my own and eventually got the rubber on by the expedient of putting clamps on holding the rubber against the window as I worked round the pane (that should really be PAIN !)

Now remember I stretched this rubber tight then deliberately cut it short before gluing and yet it obviously is now too long  :bang:

So admitting defeat I've called on the services of Shaun who works for Autoglass and is a friend of a friend - hopefully he'll be round in a few days.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 12, 2018, 10:25:32 AM
So to cheer myself up I tackled a dent in the machines plinth. This machine has been roughly handled at some time - the lower edge of the plinth at the headstock end has thumped something and been badly dented. It has a flange bent under it and unfortunately the dent extended across the bend for this flange. Given decent access and an oxy-acetylene torch knocking the flange bend back square would be quite simple, but there is very limited access to the rear of this panel - no room to swing a hammer for instance. And the torch is ruled out as there is wiring and an oil reservoir in the vicinity.


So ingenuity, carver clamps and a bit of brute force were applied to restore some semblance of order. Not perfect but better than it was  :thumbup:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: Pete. on March 12, 2018, 03:44:38 PM
That's where you need one of those spot-welder studs that screw into a slide hammer.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 12, 2018, 05:51:58 PM
Well Pete I do have a proper stud welder:

https://madmodder.net/index.php/topic,10287.msg116100.html#msg116100

I was considering rolling it out for this job, but huge current spikes near electronics that you can't replace took the shine off the idea.

The plate it's bent from is about 3 mm so fairly substantial - I suspect even M8 studs would struggle (that's the biggest it fixes) and the kink in the corner of the flange couldn't be pulled out anyway  :scratch:

I suspect it'll be filled and rubbed down before painting  :palm:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: melgump on March 13, 2018, 05:22:48 PM
 Hi Awemawson.
I think you are tackling the glazing procedure backwards. You should fit the rubber seal to the hole in the door ( or bodywork if auto) and if necessary hold in place with masking tape. Put the joint at the bottom. It is preferable that the rubber is slightly too long than too short. You then fit the glass from the outside and finally the locking strip. Always works for me.

Cheers,
Melgump.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: kayzed1 on March 13, 2018, 08:31:36 PM
I was thinking some thing along those lines, when i were a lad :lol: we used to fit the rubber to the frame then insert the glass, last the locking strip...in Mini's and Ford Escorts and the like..
Lyn.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 14, 2018, 10:36:47 AM
I've actually tried it both ways chaps with equal failure  :bang: Actually I've come to the conclusion that I've left too much gap between the size of the opening and the size of the polycarbonate so will re-make the window a bit bigger.

Today the PS2 sockets arrived allowing me to do the final drilling of the PC mounting escutcheon and give it a coat of paint. I did pick up some sockets a week or two back, but when they arrived they proved impossible to mount from the rear of the panel - I wanted to be able to remove the cable as an assembly rather than have to make it in situ and the PS2 plug end wouldn't fit through the socket mounting hole, and the thread on the socket wasn't enough to penetrate the escutcheon (2 mm)

The new ones have pigtail flying leads and rear mount onto the panel :thumbup: I'm sure that there used to be a male / female bulkhead PS2 fitting but I couldn't find one.

So today the escutcheon has been finalised and given a couple of coats of paint, and the keyboard and mouse PS2 cable assemblies made up ready for when the paint is hard.

Meanwhile my supposedly creamy white paint for the rest of the cabinet has arrived, but looks far too white to me - sample drying as I type.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 14, 2018, 01:02:09 PM
So with the paint reasonably dry (good stuff this paint!) I've populated the PC escutcheon, and re-routed the cables so at long last I don't have monitor, keyboard, and mouse cables erupting from the open enclosure rear door. So now the door can be closed and all those extraneous cables within have been tidied up  :thumbup:

I made another M6 bolt to celebrate  :lol:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 14, 2018, 04:39:20 PM
After supper I bent up a little bracket to support the Enclosure Isolator Switch Shaft, as it tended to droop a little and didn't always engage correctly.

Went remarkably well considering the two gin and oranges before and the can of Old Speckled Hen during supper  :clap:

At least now the two parts come together in correct alignment  :thumbup:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 15, 2018, 09:46:02 AM
Time to sort the stand today:

Lift off using Forklift and strops, then invert, remove castors, slap a coat of paint on, put the castors back on, put it back upright and paint the bits that were previously inaccessible.

All fairly straight forwards. I'm using the brushing version of the chassis paint that I sprayed the panels with - went on OK but a bit gloopy

I'll leave it overnight to harden before putting the machine back on.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: AdeV on March 15, 2018, 05:47:09 PM
A fork-lift is high on my list of Most Desirable Things to Own... Can you post some pictures of yours so I'm sure to get a bigger one?  :lol:  :nrocks:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 15, 2018, 05:55:07 PM
Hyster H2.50 XL Container Spec propane fired Ade - so it lifts 2500 kgs, fits inside a container for stacking and thus has a triple mast to keep the height down.

Only issue I have is the low ground clearance - no good on soft surfaces so don't go off piste  :lol:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 16, 2018, 05:15:05 AM
The paint on the stand has now hardened off so I was able to restore the machine to it's place on board - just a reverse of the Forklift trick !

Having done that stand I can now attack the rest of the paintwork - but I'm really not at all happy with the results of knocking out the dents from the plinth headstock end - it just looks horrid and will be worse when painted.

So I've bent up an 'overpanel' to cover the mess. It went really nicely. There is a little groove between the plinth and the machine tray, and by adopting a cunning technique I managed to make a very short bend that tucks into this groove and gives the impression it is the original plinth panel  :ddb:

So how did I make that extremely short bend? Well first I bent an upstand of a couple of inches, then hooked it over the edge of the guillotine with the bit I wanted hanging downward, spaced off the blade by a couple of bits of 1.2 mm sheet. Then pressing the sheet onto the spacers with a long bit of wood to keep fingers clear, I stretched a leg far enough to kick the trip bar and make the cut. It actually worked very well but would have been easier with a second person to avoid the acrobatics  :lol:

Not sure how I'l fix that overpanel. Pop rivets would be easiest but look naf. Screws into tapped holes would work but loose the 'original' look that had no fixings. Don't want really to weld for reasons mentioned earlier. I'm considering using a structural adhesive.

(It's balanced with a rare earth magnet in the photo)

. . . suggestions please  :scratch:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 16, 2018, 12:07:31 PM
Well  :ddb: :ddb: DEVELOPMENTS  :ddb: :ddb:

I've actually managed to fit the window polycarbonate into the sliding door  :thumbup: This was a result of watching yet another Youtube video :



I decided to see just how loose my already cut pane was - I'd allowed 9 mm for the web of the rubber, and according to the web site SealsDirect.Co.UK the choosen seal should have 7 to 7.5 mm, so not massively wrong. The already cut rubber seal was obviously going to be too short - I've bought another length, but I thought I'd have another try, and patch in the shortage just as a practice fitting the glazing.

This having been successful I'll pull it all off again and fit the new rubber.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: tom osselton on March 16, 2018, 04:27:31 PM
Thats a good video it still doesn't look that bad with the patch piece in your window considering what it does I'd probably glue the ends and hang a don't look sign on it!  :D
When I stop scratching my head and my lathe comes to life I'll have to give the window enlargement a try thanks for showing!
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 16, 2018, 07:00:43 PM
Well Tom I already have the replacement rubber, so hope to fit it tomorrow morning (assuming the gathering of the rams goes to plan)

It was a relief to actually get it in - I've done similar sized tractor cab windows before, but with standard factory sized glass and rubber seal.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 17, 2018, 06:24:06 AM
I did a pre-emptive strike on the rams and had them gathered before they knew what was happening, so could get on replacing the window rubber.


It went pretty well - no issue taking out the previous bit, and the usual struggle and acrobatics to get the new in but persistence won in the end  :ddb:

Now at least there is only one joint at the top and it's slightly neater than before (not difficult!)

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 17, 2018, 09:45:19 AM
As I can't get on stripping the cream coloured cover off  and sand blasting it due to the weather (a bit of snow this morning) I decided to attack the keyboard.

The user facing surface is legend printed on the underside, but it's not a membrane keyboard as such. There are individual switches below on a PCB. Now this upper surface has suffered a bit over the years. The lower right hand corner has had impact damage, and the plastic is peeling away all round the edge. The correct repair is to install a replacement plastic membrane, or even a keyboard, but as neither are available a work around was needed.

I decided to make a bezel that being held down by the same screws that retain the keyboard, would trap the plastic preventing further peeling, and cover the  major damage areas.

So I created a simple drawing in Autocad, exported a .DXF to Sheetcam to produce a  .TAP file of G code which I imported to MACH3 driving my CNC Plasma Table.

(Did I ever tell you I LOVE my CNC Plasma Table  :ddb: :ddb: )

It makes what would be a time consuming job simple, accurate and fast - how did I ever manage without one - how do you  :scratch:

Being a low mass item, once cleaned up and suitably drilled I was able to get a couple of coats of black satin on it before lunch by the simple expedient of accelerated drying using a hot air gun.

Popped it on, tested all still works - job done and I think the keyboard will last OK now for a few more years
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: nrml on March 17, 2018, 03:08:22 PM
Why don't you get a replacement panel made? There seem to be a few companies doing this sort of thing.
https://www.fasciagraphics.co.uk/our-products/graphic-overlays
https://www.bex.co.uk/what-we-do

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 17, 2018, 03:12:06 PM
Money perhaps  :lol:

Bezel = Zero cost - all bits to hand, all equipment needed to hand  :ddb:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: nrml on March 17, 2018, 03:33:19 PM
Can't argue with that :thumbup:.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 18, 2018, 10:41:11 AM
Apart from touching up, I think I've finished the black paint  :thumbup:

Quite a bit of rubbing down, masking and spraying going on yesterday and today - not perfect but perfectly acceptable.

. . . just the cream to do now  :clap:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 18, 2018, 10:46:19 AM
I've decided to experiment with the 'too white' machinery paint that I had mixed to RAL 9010

Having delved inside to a bit of the cream paint that hasn't been exposed to the sun, in fact it is far whiter than the rest of the machine. So I have diluted a bit by 10% and sprayed the headstock end removable  panel to see how it comes out.

All the black panels have been rattle cans (aerosols), the base frame was brush painted, but for the cream I'm using a small 'touch up' gun in the hope that it's a bit more controllable than my normal sized paint sprayer.

However this panel needs to harden off and convince me it's going to be OK before I commit to doing the rest.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 19, 2018, 06:17:02 AM
To facilitate the clean up of the remainder of the cream paintwork, which has rust spots in places and is generally a bit knocked about, I decided to revive a bit of kit I've had for decades, and frankly I'd forgotten I still had  :palm:

It's a 'Drester  1650-844' Spot Blaster. I think it was intended for the motor trade for detail blasting stone chips and little dents and is of a cunning design. The sphere is half full of abrasive medium, and just above the half way level is an extract port connected to a workshop vacuum cleaner. Fitted to the top is a co-axial hose leading to a hand held pistol. Down the  inner hose travels abrasive medium carried by compressed air and picked up by a 'straw' being sucked by a venturi. The media impacts the work, does it's stuff, and is sucked back up the outer hose and back into the sphere, any dust going into the vacuum cleaner.

This results in a blasting operation WITHOUT abrasive going everywhere (so long as the rubber nozzle is held firmly in contact with the work)

I picked this up from an advert in the local paper at least 20 years ago, and at the time I wasn't very impressed with it. I now realise that was because my compressor at the time was inadequate, and I was using actual sand.

Digging it out today I replaced the rotten rubber air hose, chucked out the sand and replaced it with fine crushed glass, and find that actually it's quite good for it's intended purpose of small detail work, and it will be very useful preparing the rest of the MIRAC for painting  :thumbup:

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: tom osselton on March 19, 2018, 12:24:37 PM
I have one that is about the size of a paintgun that was bought years ago from Princess Auto but it is only good for a 3/4 - 1" spot if I remember right.
Your doing a great job on the machines as usual!
I pulled some cards out of mine and put them back in hoping the problem was a bad connection but not so lucky I"ll go back out today and scratch my head some more looking at the scematics. :doh:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 19, 2018, 01:04:04 PM
Not so sure there Tom, it seems to be one step forward - two back today  :scratch:

I'd removed the auto oiler / lubrication pump before panel spraying, and also cut a hole to replace the fixed power cord clamp with a 15 amp IEC socket. So today I wanted to refit the oiler and connect up the socket - nice and simple.

First I wanted  to investigate why the oil reservoir was swathed in blue insulation tape - as I'd guessed it was cracked - no big issue, I gave it a good wash out in very hot soapy water (can't use a solvent as I don't know the plastic) to de-oil the crack, then glued it with a speciality plastic glue. Bolted it back on the machine and re-made the five drive wires (this oiler runs when the spindle is turning).

Then I made up a little cableform from the termination block that the the fixed power lead went to, to the IEC input socket. Powered up and it tripped my RCD in my main fuse board.  :bang:

Lots of faffing about looking at wiring and scratching my head - it all looked fine - but I dis-connected the oiler anyway, tried again and it was still tripping. Hard to make an error in the Live Neutral and Earth cableform - and no there wasn't !

Lots of experimenting trying to isolate the leakage, but as yet not found it - if I disconnect the earth tag on the mains input it powers up ok and the chassis floats at about 100 volts above earth   :bugeye:

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 19, 2018, 01:27:36 PM
Now I couldn't for the life of me understand how I could have introduced an earth leakage fault doing what I've done.

So as Sherlock Holmes used to say, when every other possibility has been eliminated what remains must be the truth - look at the old mains lead - sure enough the earth was disconnected - this is NOT a new fault, I've tripped over someone else's unfinished problem   :clap:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: b4dyc on March 19, 2018, 02:27:59 PM
That will give you something to do then. You was looking like you were near finishing otherwise  :Doh:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 20, 2018, 07:29:33 AM
So a bit of diagnostic progress:

Removing the earth from the input IEC connector and putting an AVO8 Mk7 on AC volts between the IEC Earth tag and the removed machine Earth, and the machine powered up I was reading 88v AC - roughly what I'd read  before and enough to give you a tingle on a grazed knuckle - (ask me how I know!).
Now the internal resistance of the AVO is high enough to limit the earth fault current sufficiently to not trip my 30mA RCD in the fuse box, but is low enough to swamp stray capacitive effects that you would get using a modern electronic meter like a Fluke.

So by a process of elimination working though all the mains using devices in the machine I found that the main spindle drive inverter to be the culprit.  Now as inverters switch at high frequencies they do tend to cause quite a bit of earth leakage, but in this case I'm sure it is excessive. I strongly suspect the input filter components in the enlarged view, but getting at them to replace wouldn't be easy.

As I have a 13 amp socket for lighting on my three phase Bridgeport, that is derived from phase 1 and neutral, and the three phase distribution has a 100mA RCD I moved the extension lead from a 30mA protected socket to this 100mA protected socket and sure enough it didn't trip (I'd left the AVO in circuit but rotated the knobs to measure AC 10 amp so effectively a short circuit restoring earth continuity.

Out of interest I turned the knobs back to AC volts and I was measuring very low volts - nothing like before where I had 88 volts AC. All very odd - so I put the machine back onto the 30mA protected circuit with a solid earth by removing the AVO and pushing the faston connection back together, and darn me the bally thing works and doesn't trip the 30mA RCD any more  :clap:

The only conclusion that I can draw at the moment is that whatever was causing the leakage has been blasted away by the (presumably) less than 100 mA current that initially flowed, and is now in oblivion  :scratch:

So although I don't like disappearing faults, at least it's working and no longer dangerous as it was.

To prove all was working I tried to make another M6 brass bolt, but the darn program wouldn't run - couldn't fathom it, until I noticed the little bit of text saying 'Low Lubrication Oil Level' - of course I hadn't filled the reservoir when I glued the crack to give it time to set. Filled her up, off the program went . . . .BUT the crack still leaks  :bang:

...ah well . . . :med:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: nrml on March 21, 2018, 06:36:15 AM
Why don't you fold and solder a sheet metal box that can sit within the cracked plastic oil reservoir? It would be a simple solution for the problem. My personal experience with gluing plastic containers of any sort has always been bad.

Do you think that the tripping might have been caused by a bit of swarf in the electronics which fell off when you were dismantling the boards?

Edit:
The reason I ask is that there appears to be some swarf / dust on the black sheet metal panel and on top of the lowermost mosfet in your last two pictures.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: russ57 on March 21, 2018, 06:51:27 AM
Another possibility ; although I do like the swarf idea.
Moisture in some insulator. Leakage to earth.
Letting it run for a while with higher leakage allows it to dry.
But the smoking gun is still the disconnected earth. Obviously been a long standing problem. Maybe a leaky cap which reformed?



Russ

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 21, 2018, 07:13:07 AM
Russ and NRML thanks for the suggestions. Swarf is always a possibility but I did give it a comprehensive blow out with an airline several times. I like the tin box idea - I shall store it away - the manufacturers agent says that the reservoirs are still available and I'm awaiting their pricing.

The machine has been in a heated and dry environment for quite a while now so I doubt dampness was the cause, and certainly no sign of it in the culprit inverter.  It was plugged into the 100mA protected circuit for probably less than half a minute - just long enough for me to realise that it hadn't tripped !

As was said, the disconnected earth wire is a smoking gun - someone has been down this path some years ago. If the problem returns I'll have the inverter out on the bench and do a proper diagnosis, my suspicions of the filter components are entirely without evidence - just based on previous experience - so I suppose you'd call it prejudice. (which after all is only making decisions based on prior experience!)

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: AdeV on March 21, 2018, 04:10:08 PM
Quote
prejudice. (which after all is only making decisions based on prior experience!)

Hmm... actually prejudice is the exact opposite of making decisions based on (prior) experience...!

My favourite definition which fits here I think: “Intelligence is the ability to learn from your mistakes. Wisdom is the ability to learn from the mistakes of others.” I'm pretty sure that means you have wisdom here  :scratch: :lol:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 22, 2018, 09:59:27 AM
Frustrating day today trying to remove the white casing for stripping. All screws removed but it seems horribly likely that there are some only accessible from the rear having removed the large electrical box. This would be a major undertaking - lots of cables between the two. But also rather puzzling, as I'm sure the cover was supposed just to unbolt and lift off to allow servicing of the  spindle motor and stepper motors.

There seems to be a cavity formed in the metal work 'up high' above the lathe itself - and I suspect hat it has a rear mounted access panel under which are the elusive screws.

In desperation I've fired a question off to the Denford Forum, but it's rather in-active so don't have high hopes of help  :scratch:

Meanwhile the reasonably good news is that a lube oil reservoir IS available at about £30 which isn't too bad.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 22, 2018, 10:28:09 AM
So another email from  the Interlube agents, and the 'about £30' has grown to £38 plus VAT plus £20 carriage plus VAT - or actually £69.60 in total. There is a 4-5 week delay 'as they are made to order' !!! The idea of a tin box inside becomes increasingly attractive, or I might even 3D print one.

Meanwhile I'm draining out the old coolant - the constant dripping in the background doesn't half make me want to keep going for a p...  :clap:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: nrml on March 22, 2018, 11:25:32 AM
A 3D printed reservoir is a great idea, but what would you use to seal it to make it water tight? Will epoxy play nicely with lubricants?
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 22, 2018, 12:27:21 PM
Acetone vapour is supposed to work for ABS. I've not tried it as a vapour but I have dipped parts in acetone. I'd imagine another approach would be to dissolve abs in acetone and make a 'wash' to seal it.

Perhaps one of the 3D printing experts can pipe up - ping Joules !

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 22, 2018, 01:36:50 PM
So back to the white paint problem  :scratch:

It looks pretty certain that the only way to lift the cover off is to split the electrical enclosure off the back of the lathe, and gain entry from the rear. However this is by no means guaranteed. It looks that all the wiring for the enclosure enters and exits at the top right hand corner viewed looking into the  enclosure. The two seem to be held together by four large cap head bolts, and the one that is visible from the lathe side is welded to the rear panel of the lathe enclosure with the nut on the electrical enclosure side. Hopefully they are all the same.

Now it certainly looks as though were the four nuts removed and the enclosures separated a bit, the electrical one could be swung through 90 degrees or so to give rear access to the lathe enclosure, which may or my not allow me to unbolt the rest of the cover that I want to lift off  :scratch: It all depends on there being enough cable slack, and until I try I won't know .

BUT there is a GOTCHA  :bang: All the components in the electrical enclosure are mounted on a separate inner panel (which is a common practise) and there are large holes cut in this panel to give access to the nuts, BUT the panel has slipped down and the holes no longer align - a socket or box key will not engage the nuts  :bang:

Now it should be fairly easy to realign the inner panel - the machine must have been dropped a bit at one time and it's settled the panel downwards - but if I shift it my PC mounting and PC bezel will no longer fit as they are aligned with the shifted panel.

SO - to attempt separating the enclosures I'll have to very carefully mark where the inner panel now sits, shift it upwards, undo the nuts, hopefully separate the enclosures and then hopefully get the cover off and paint it, and the re-miss-align the inner panel ! What a kerfuffle  :scratch:

. . . or I could do a bodge job on the paintwork - just hand rub it down, brush or roller paint it and call it done . But I don't like rollered or brushed paint work on machines, and the rusty bits really do need the attentions of a grit blaster . . . . . . decisions decisions . . . . .
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: Pete. on March 22, 2018, 04:11:07 PM
Denford seem to love to make their stuff difficult to dismantle. I bet their designer used to work for Leyland or something. I had a denford lathe that I needed to get the QC gearbox off the front only to find that 3 of the four bolts are easily accessible but the fourth is down inside the headstock sump in the bed and the only way to get at it is to completely remove the headstock, for which you have to remove the motor covers, the splashback, the interlock wiring the belts the motor speed change gear and the chuck guard interlock and even the lo-volt light. All to get at one damn bolt.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: jb3cx on March 22, 2018, 04:34:22 PM
Andrew I scrapped a couple of bridgeport interacts a few years ago kept just about everything apart from the carcass,I may have a lube oil reservoir lying about somewhere,if that would do the job .
Regards Peter
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: tom osselton on March 22, 2018, 04:53:01 PM
I was just wondering if you have the old one could you make a clay mold or something and use a plastic casting resin?
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 22, 2018, 05:32:59 PM
Sounds familiar Pete !

I decided this evening after supper to drain the leaking Interlube 'E' lube pump tank and clean it up ready for cloning by 3D printing. But when it was nice and clean the thought struck me that I'd missed a rather obvious other step to cure the leak - apply more glue !

This Bison plastic glue seems to be good stuff - the actual original crack is very firmly bonded and the glue rock hard, so I've over painted the area with some more and in the morning I'll fill it with water and see how effective it is !
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 22, 2018, 05:34:19 PM
Andrew I scrapped a couple of bridgeport interacts a few years ago kept just about everything apart from the carcass,I may have a lube oil reservoir lying about somewhere,if that would do the job .
Regards Peter

Peter, the Interact ones are much larger - this is a diddy little thing, but thank you so much for the offer
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 23, 2018, 07:26:16 AM
So morning has arrived and time for a test of the gluing !

Filled up with tap water, stood on a stand-off as part of the crack is underneath, placed on light blue towel that turns dark blue if damp, and left for a couple of hours as I take the dogs for a walk.

Come aback and NO drips  :ddb: Now I assume water is more able to find cracks than oil as the viscosity is less but . . . .  :med: I'll leave it for the rest of the day anyway before re-installing just in case.

Looks like £2.99 Bison plastic glue won the budget challenge over the £69.60 replacement.

Oddly eBay this morning has been flooded by Chinese lube pumps, many at under £70 including postage, but the smallest is a 1 litre which is twice the size of this one.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 23, 2018, 09:05:32 AM
Reservoir  still leak free  :thumbup:

OK so I've finally decided - the cover stays on and I'll prepare and paint it in situ. There are just too many complications removing the cover - it turns out that the cableforms for the tool changer and spindle motor and encoder all go through holes in the cover, and although some have plugs they are too large for the holes.

So I've done a trial strip using a dichloromethane and methanol containing paint stripper and it's worked quite well . There is no question now regarding the colour having removed the tailstock end rubber window trim - it's a very white white !

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 23, 2018, 12:19:09 PM
OK the trial stripping was a success,  so no more procrastination, get on with it!

The order of operations here of course is all to cock, as the white should have been painted before the black - but I'd expected to be able to remove the cover and as we know . . . . .that wasn't happening.

I have no doubt that I will lose a bit of black paint and have to re-touch in places, as masking tape isn't the best for separating paint and paint stripper - particularly this excellent stuff that passes through neoprene gloves to set you tingling !

One major application of stripper followed by a second 'get the missed bits' followed by soapy water and a stainless steel pan scrubber and it's almost there. I'd really like to do the internals, and I suspect that the panel round the spindle will come off but if I paint the tray it will have to be brushed. The inside of the front panel though is pretty impossible to get at, as is the 'roof'

A load of rubbing down and finessing needed  now but that's for another day.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 23, 2018, 02:34:30 PM
I thought that there should just be time before supper to remove the 'spindle panel' that sits behind the chuck. What a palaver  :bugeye:

First remove the internal light as it blocks some screws (covered in swarf glued with congealed oil)
Then unbolt and disconnect the wiring to the Tool Turret
Then unbolt the screws holding the plate onto the headstock when you find actually it's nuts and bolts from the other side !
Then unbolt the wiper arrangement and you think you are there - but no!
Then unbolt the lower wiper (which took a bit of heat to get undone) . . are we there yet  . . . NO!
Then cut off the seized coolant pipe . . .

. . . hooray we have a panel that can be stripped for painting tomorrow as that's enough for today!
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 24, 2018, 07:29:16 AM
Hopefully this morning has seen the end of removing bits and paint stripping  :thumbup:

I started by removing the control button panel components first of all taking a good picture of the wiring for when it goes back together. I then peeled off the torn Decal sticker and carefully measured it up, making an embryo one for test purposes on the CNC Laser cutter. (I'll do a 'back engraving' job on the final version)

Then I paint stripped the button panel and the swarf tray and the spindle panel (that I removed last night)

It's all been given a pretty thorough clean up, but will need a rub down and more preparation before I actually spray everything. It's going to be great fun masking this lot up  :clap:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 25, 2018, 04:27:42 AM
Not going to be able to get much done today as I have social commitments,  but I did manage to draw up and cut this masking paper dispenser before breakfast before anyone found me  :lol:

I'd got fed up chasing the roll round the table and then trying to cut to length single handed. The tear off cutter is a bit of 'DIN Rail' that was lying about.


I've probably never told you . . . .I love my CNC Plasma table . . . . . . Oh have I, well I never  :ddb:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: kayzed1 on March 25, 2018, 03:11:06 PM
Dam you can go off people you no :dremel: :clap: :thumbup:
Lyn.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: hermetic on March 25, 2018, 03:13:08 PM
Had one of those dispensers on my workshop wall in the seventies, it had masking tape as well, and as you pulled the paper off, it applied the tape to the paper. Very quick when it worked right, and a bugger when it didnt, you needed to use good quality masking tape!
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: vtsteam on March 25, 2018, 04:04:02 PM
If in doubt, use more glue...... :lol:  :beer:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: vtsteam on March 25, 2018, 04:05:54 PM
btw, I'm guessing that's acrylic.

Nice having a see through reservoir, for obvious reasons.  :thumbup:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 25, 2018, 04:09:43 PM
Well Steve, yes it probably is.

As the MIRAC is still waiting for a coat or two of white paint I've not refitted the reservoir, which is still sitting as per the photo next to the workshop coffee making area AND IT'S NOT LEAKED  :ddb:

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 26, 2018, 07:44:21 AM
I set too masking up the MIRAC this morning - outside is fine but the interior was a pitta  :bugeye:

However the paper dispenser came into its own - would have been tricky without it.


... then the big decision - spray indoors and get overspray over the rest of the workshop, or wheel it outdoors where if the wind picks up I'll lose the paper masking and insects can be an issue. Well it's a dry day with the sun shining and only a light breeze so I pushed it outside.

On the overspray issue, I'm using a 'detailing gun' and actually the overspray is fairly minimal though still there.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 26, 2018, 07:47:10 AM
So out she went and got the first coat - next one due in 24 hours so she's back inside until then.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: DaveS on March 26, 2018, 08:49:10 AM
Looking very good, and being outside it even looks bigger, must be the white  :D  :bugeye:

Finish looks as smooth as Powder Coating  :update:

 
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 26, 2018, 11:19:24 AM
It'll be better with a second coat to be honest Dave.

So what do you do while paint is drying . . . . .sand blast and spray black the door slider rails, and have a go at finishing off the label for the Button Panel.

This I do by spraying the reverse of the polycarbonate panel in black, then reverse engraving the text using the  CNC laser engraver. It hasn't come out good enough to use on this occasion for two reasons. Firstly I didn't leave the paint long enough and the white infill has reacted with the black background. Secondly I did the engraving at slightly too high a power setting and the front face is distorted.

Never mind, that the good thing about CNC - tweak the commands and do it again, you only need to alter the bits that were wrong rather than the entire gizmo.  :thumbup:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: tom osselton on March 26, 2018, 02:38:20 PM
A person I know just made a panel for his lathe.

https://canadianhobbymetalworkers.com/threads/my-new-lathe.292/page-3#post-8479
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 27, 2018, 03:22:36 AM
Raining today, so the second coat has had to go on indoors. Dust sheets everywhere !

First coat went on rather dry and didn't all blend so I used a bit more thinners this time, and of course went the other way and got a couple of runs   :bang: They'll be cut off with a razor when dry and touched in with a small roller.

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 27, 2018, 05:27:34 AM
I need the paint to be good and hard before I shave the runs, and also before re-assembly. So I've set up a 4kW fan heater to bake it now it is touch dry.

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: hermetic on March 27, 2018, 02:08:08 PM
Runs on paint is a bore, and I am painting a Ford KA tomorrow, so I will be careful, but the guy who taught me to spray always carried a clean 1/2 brush in his top pocket, and would brush the runs away, just to get rid of the bulk and speed the through drying of the paint so it could be flatted quicker. This avoids the sinking feeling in the pit of the stomach when one realises that the run you have just attacked with the wet and dry is now a smear of semi solid paint, and you have pulled it back to the primer! start again time!! Luckily the KA is basecoat and lacquer, so  build up solid colour, then lacquer it all to a finish! This job has reminded me why I gave up car repairs in about 1982!
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 28, 2018, 05:12:56 AM
Made a few alterations to the Button Panel Label and re-did it producing a more satisfactory result.

a/ I changed the font to Ariel Black

b/ I removed the black paint by scanning with the laser rather than doing a light cut to eliminate the 'two line' effect

c/ I filled the lettering with water  based emulsion paint as I found that the white acrylic I'd been using was dissolving the black surrounding the letters


I think this one will pass muster  :thumbup:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: russ57 on March 29, 2018, 05:55:45 AM
Made a few alterations to the Button Panel Label and re-did it producing a more satisfactory result.

a/ I changed the font to Ariel Black

b/ I removed the black paint by scanning with the laser rather than doing a light cut to eliminate the 'two line' effect

c/ I filled the lettering with water  based emulsion paint as I found that the white acrylic I'd been using was dissolving the black surrounding the letters


I think this one will pass muster 



Russ

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 29, 2018, 02:38:25 PM
Not much done today as a couple off additions to the livestock were due - a pair of Berkshire weaners - well actually three were due but the breeder made a c....up  :bang: Never mind he's making good the numbers with a Saddleback weaner on Wednesday   :thumbup:

However I did find time to strip off the masking paper, make good and hand touch up a bit of (expected) damage to the black paint, and re-fit the control button panel and the control keyboard.

Can't really do much more as an expected delivery of screws hasn't materialised - nor will it with the Bank Holiday for a few days, but probably a 'good thing' as the paint is still a bit delicate and it'll force me to be patient. (never easy!)
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on March 30, 2018, 10:36:21 AM
As I'm held up for a bolt delivery I decided to re-run the coolant pipe as the original is old and brittle.

Obviously this starts at the coolant pump, snakes through the body of the machine and terminates on a block bolted to the spindle panel. Now when I dismantled this it was evident that one of the bolts had been cross threaded and inserted at a rather jaunty angle. So firstly I re-tapped the block. I imagine that originally the block was offered up after the spindle panel was mounted, and the cap screw inserted on a long driver, hence the cross threading. So I decided to bolt it on first and loosely fit the panel until the bolts arrive.

Didn't quite go that way, as the panel and rear protuberances from the block need to be fully seated before a little protection panel (that protect the button panel wiring) would fit on. So the Spindle panel was pushed fully home and given a single screw to hold it in place.

Having got the coolant pipe done there was nothing stopping me re-plumbing the lubrication pump, so this was next on the agenda.

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on April 06, 2018, 12:27:29 PM
At long last the screws that I had on order materialised and I could put the lathe back together. All went reasonably well, not too many paint chips to touch up.

Glazing the Tailstock end window was a bit of a struggle, and there was a bit of paint damage when I'd finished, but I got there in the end  :thumbup:

Having re-set the rails that the door slides on it was necessary to first do a trial fit and make sure it still slides ok - which it did.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on April 06, 2018, 12:31:42 PM
Then it was just a case of plodding on fixing internal and external panels, interior light etc..

A quick run through of the M6 bolt program proved it still works  :lol:

So that's just about that - just got a little retainer clip to fit to prevent the door being lifted off

. . . remember how it was? . . see the last picture
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: hermetic on April 06, 2018, 01:50:03 PM
Another cracking save Andrew!!, it really looks the part now. So, what are you going to make with it, and when is the video release date?
Phil.
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: tom osselton on April 06, 2018, 01:58:39 PM
Another great transformation thanks for posting it is always a pleasure to follow along!
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on April 06, 2018, 02:14:21 PM
Thanks for the kind words chaps :thumbup:

Not sure of it's future. The 25 mm spindle bore makes it a bit limiting for some things so I suppose if something a bit more meaty turns up I'll pass it on, but at the moment, as it can easily be pushed into a corner when not in use I'll hang on to to, (unless someone offers silly money for it - unlikely as I'm not advertising it!)

It's been an interesting exercise and has convinced me that I need to investigate setting up to spray 2K paints - waiting for coach paints to harden is boring !!!!
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: JerryNotts on April 07, 2018, 03:43:34 AM
Great refurb. When you started thei project I wondered why you had acquired this small machine, but now its finished you must have been able to see beyond the cr...y state to what lay hidden beneath.
Jerry
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on April 07, 2018, 03:57:04 AM
Jerry, it's what floats my boat - trying to make silk purses out of sows ears . . . .


. . . . just remember, inside every lump of rusty metal is a shiny new part waiting to emerge  :lol:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on April 07, 2018, 06:11:48 AM
Of course these things are actually NEVER finished. It wasn't until the postman delivered a long thin parcel this morning that I remembered that I hadn't replaced the door wiper strip - another long awaited delivery  :bang:

A bit fiddly to fit as not quite the same size as the original, and the two smaller bits had to have a bit of a hair cut to allow the door to slide reasonably freely - but now fitted.

. . . .so perhaps NOW it's finished  :scratch:

But then - I need to decide what to do with that opening where the original (tiny) monitor was fitted - a door - a drawer - perhaps a cuckoo clock that pops out at the end of a job like the flashing "Cycle Finished" lights some CNC machines have  :lol:
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: nrml on April 07, 2018, 02:15:02 PM
Yet another excellent restoration thread :clap:. Not quite in the same league as the Traub restoration but still very entertaining and educational. You sir are a real inspiration to us all :thumbup:.
Is the tool changer going to get a tear down and re-grease at some point in the future? It sounded a bit noisy in one of the earlier videos. Has that resolved ?
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: AdeV on April 07, 2018, 02:34:14 PM
But then - I need to decide what to do with that opening where the original (tiny) monitor was fitted - a door - a drawer - perhaps a cuckoo clock that pops out at the end of a job like the flashing "Cycle Finished" lights some CNC machines have  :lol:

How big is the opening? Can you fit a small TFT monitor (perhaps shorn of its plastic casing, at least around the edges of the screen) in there?

Failing that... cup holders? So you can have a nice brew while the machine does the hard work? Hey, perhaps one of these (https://www.sonicdirect.co.uk/prod/Small-Appliances/euronics/Swan-STM202N-Vintage-Teasmade-with-Clock-Alarm-in-White-600mL?utm_source=googlemerchant&utm_medium=feed&utm_campaign=googlemerchant&gclid=EAIaIQobChMIoKb3keao2gIVorvtCh3GkgDdEAQYBSABEgJ1_fD_BwE) would fit the hole? You'd probably need to make a sliding bracket to access the mug/fill with water1... hack the timer so that when there's X minutes left to run on the cycle (where X = however long it takes to make a cup of tea), it switches it on  :lol:

1 Or just plumb it into the coolant system, for an automatic fill! Might make odd-tasting tea though...
Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: awemawson on April 07, 2018, 08:16:27 PM
Nrml
.
As far as I can tell the tool changer noise is actually normal for the model. There is no way to re-grease it without a total strip down as there are no external points to introduce any lubrication.

But at the moment I've been put on other jobs - rebuilding a totally useless rat eaten and rotten chicken shed on wheels that apparently has some sentimental value. My solution was a box of matches and a gallon of paraffin, but apparently that's not acceptable. I even had a builder lined up to put up a tasteful brick one to match the pig palaces, but that also was vetoed  :bang:

Timber shed - rat eaten in three years
Brick equivalent = good for 25 years minimum

. . . no contest, but then what do I know  :bang: :bang: :bang: :bang: :bang:

Title: Re: Rebirth of a Denford MIRAC CNC Lathe
Post by: Pete W. on April 09, 2018, 04:30:28 AM
Confucius, him say:

"Happy wife - happy life"   :D   :D   :D   :D   :D   :D