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Gallery, Projects and General => Project Logs => Topic started by: shipto on March 12, 2017, 04:31:44 PM

Title: Another homemade milling machine
Post by: shipto on March 12, 2017, 04:31:44 PM
Since I have allowed this to get in the way of other stuff I should be doing I thought I would start the thread.
I have wanted a mill for a long time and despite following searches for one close to to me I havent been able to find one thats the right size, the right money or combination of those.
pic 1) Is a bit of 150mm X 100mm x 5mm wall box section that was left over from a one off job at work which I have held onto for years with bits for my origional idea for knee slide welded on.
pic 2) It needs some holes for mounting it on the lathe for facing etc. These will probably be no use other than increasing the rigidity after it has been machined so I will just put some caps over them.
pic 3) I want to be able to move the head up and down to allow drilling operations so this pad will have the dovetail for that bolted to it. If all goes to plan I will be able to get rid of the terrible drill press I have.
pic 4) Finally for now the discussed (in the design shop) bit to allow future use as a horizontal mill and a extra clamping hole.
Title: Re: Another homemade milling machine
Post by: shipto on March 13, 2017, 06:45:35 PM
So first post was all pics taken at work and after I had finished trying to work out if I needed anything else on it I took it home and mounted it on my lathe so I could face of the bits that matter flat pic 1 and 2.
Another item I have been hoarding was aquired when our company brought out a failing competitor many years ago (missed out on a arbour press which was chucked while I was in between factories  :doh: ) Anyway it was a old solid cast iron bender capable of bending probably 8mm X 100mm flat with a big enough tube to pull it round. I used it a few times but it needed a permanent solid base and it wasnt useful enough to warrant the space. Now it may seem like sacrilege but I cut it up for this project and pic 3 shows a bit of it being turned into a dovetail guide for the head of the mill while pic 4 shows it in place.
As you can see the bandsaw at work struggled a little to cut it up but the mark will have no effect on the operation of the mill.
Not sure if theres a better way to check but pics 5 and 6 tell me its not bad at all for straightness.
Title: Re: Another homemade milling machine
Post by: shipto on March 19, 2017, 04:12:01 PM
After much tedious machining with my lathe during which time I often thought really need a mill to do this  :doh: I have 3 of the bits for the knee slide sorted out the pic shows them in place but not yet fixed I am still mulling over how to ensure they are fixed on straight.
Title: Re: Another homemade milling machine
Post by: ieezitin on March 20, 2017, 04:57:36 PM
Interesting... Very nice work, you will be rewarded well when its finished..

Anthony.
Title: Re: Another homemade milling machine
Post by: sparky961 on March 20, 2017, 08:44:16 PM
After much tedious machining with my lathe during which time I often thought really need a mill to do this  :doh: I have 3 of the bits for the knee slide sorted out the pic shows them in place but not yet fixed I am still mulling over how to ensure they are fixed on straight.

Are you trying to attach them by welding and have them come out straight/flat enough to use as ways?  I hate to sound like a doubter, but that's not likely to happen without some work post-welding.  Bolting, maybe... but not welding.

Maybe you should build a lathe.  It is said that's the only machine tool that can replicate itself.  :bang:
Title: Re: Another homemade milling machine
Post by: shipto on March 20, 2017, 09:30:43 PM
No the slides are all cast iron so will be bolted onto the steel

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Title: Re: Another homemade milling machine
Post by: sparky961 on March 20, 2017, 10:04:37 PM
Ah, yes you did mention that above.  My apologies.

For measuring flatness/parallelism, the best would be to set it up on a large surface plate, but you may not have access to that.

Can you set up an indicator to run on one side to check the alignment to the other?  If it isn't aligned, then you're probably going to need shim stock and tapping things around with a small plastic hammer to get it aligned.  Once you get it where you want it, you should drill for dowel pins (tapered, usually) to enable disassembly/reassembly and to make sure they stay where you put them.

Or, using a smaller surface plate (or other surface flat enough by your own standards) you can print it and scrape it flat.

There are a few ideas here, but I'm just kinda throwing them out there because I can't quite visualize exactly how you need to align things.
Title: Re: Another homemade milling machine
Post by: shipto on March 21, 2017, 04:32:36 AM
Parralel between the head slides and the knee slides is my biggest concern if flatness became a issue I could sort that by skimming it as I did with the mounting points as above.

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Title: Re: Another homemade milling machine
Post by: shipto on March 21, 2017, 05:40:08 AM
Ok I think I have it I am going to hold off doing anything with knee slides and get head slide finished and lapped in. Then once that's running nicely I can clock against the side of the upright which should get me straight enough. I can then use the top slide to set up the knee.
What could go wrong :)

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Title: Re: Another homemade milling machine
Post by: shipto on March 23, 2017, 05:17:16 PM
Might be jumping the gun but my lovely wife brought me the collet set for it.
I actually want the one with a 80mm chuck but they had sold out of those so got me the 100mm for the same price.
Title: Re: Another homemade milling machine
Post by: awemawson on March 23, 2017, 05:29:12 PM
Wohay ..... keep that woman  :thumbup:
Title: Re: Another homemade milling machine
Post by: shipto on March 23, 2017, 05:49:47 PM
Wohay ..... keep that woman  :thumbup:
:lol: she going nowhere for some strange reason she seems to love me  :loco:
Title: Re: Another homemade milling machine
Post by: shipto on March 24, 2017, 06:21:59 PM
Yet another job that needs milling  :doh:
I have almost done the head saddle but I need to mill out a recess to fit the rack that will let me use it as a drill.
The rack and pinion are from a drilling machine that went kaput at work and this is part of the bits I salvaged from it. Sometime pays to be a hoarder especially when you can hoard stuff at work  :lol:
I am going to have to think very carefully about my next steps because I would like a 3 speed milling head which will require sourcing or making 6 gears and if I am going to make them I will probably make a temporary head so I can use it to make them.
Title: Re: Another homemade milling machine
Post by: sparky961 on March 24, 2017, 09:39:39 PM
That lapping plate video from Tom Lipton you mentioned in another thread had him using a carbide tipped circular saw blade on cast iron.  I admit I was cringing a bit, but if that's all you have then have at 'er.

I recall one of my first "milling" projects, which was to "mill" out a slot in aluminum using a Dremel tool, cylindrical burr, and router base.  Very slow, but it did work.  I bet if you stuck a 1/8" carbide end mill into a rotary tool and took small depth cuts using a straight edge on either side as a guide you'd have it done pretty quickly.
Title: Re: Another homemade milling machine
Post by: shipto on March 25, 2017, 06:00:43 AM
I dont need to resort to that sparky I can manage on my lathe it just seems ironic how many milling operations I am having to do with my lathe to make the mill and I havent even started the knee yet.

rather than new post I will put what little I have been able to do today on this one. Been making the wife some shelving for her greenhouse or STAGING as the know-it-all-father-in-law once told me its called but anyway I was going to use m3 bolts to fix the rack in but then thought why bother just make it fit in tight and it cant move anywhere so thats what I did.
Tomorrows task is to make a hole in the saddle to let the pinion mate with the rack in the right place.
Title: Re: Another homemade milling machine
Post by: vintageandclassicrepairs on March 25, 2017, 05:36:34 PM
Hi Shipto,
Have you thought about using a VFD and 3phase motor rather than going to all the trouble making a gearbox and then only having three speeds ?
Another option would be variable pulleys ala Daf variomatic ? also used on most modern mopeds
you would need to be able to control the movement of the pulleys rather than the centrifugal(?) mechanism used on them
I have seen old motorcycle gearboxes used to provide usually four gears on "Mad Mod" machines  :scratch:

John
Title: Re: Another homemade milling machine
Post by: shipto on March 25, 2017, 06:30:35 PM
A vfd would be nice but probably too expensive for me at the moment and to be honest I hadnt even considered the variomatic option I may look at that  :coffee:
However it wouldnt be just 3 speeds as my plan is to have a 4 or 5 speed stepped pulley running a quill which would then go to the 3 speed gearbox allowing up to 15 speeds. It will most likely have to have a temporary head setup to start as whatever I decide to do will be too difficult to do with the lathe and thus it will have to make its own final head setup.
I did think for a short while about using a 150w dc motor I have which came off a micro lathe but I think power would be a issue with that.
Title: Re: Another homemade milling machine
Post by: mexican jon on March 25, 2017, 07:53:12 PM
A vfd would be nice but probably too expensive for me at the moment

I'll happily send you a brand new (ABB Part # ACS55-01E-02A2-2) 0.37KW / 1/2HP rated VFD if you got a motor to suit or even if you can get a motor easily  :beer: (I've got 1 or 2 from an old job)

I believe that anyone who is mad enough to build there own mill  :loco: deserves a little help  :thumbup:

Title: Re: Another homemade milling machine
Post by: shipto on March 25, 2017, 09:28:25 PM
A vfd would be nice but probably too expensive for me at the moment

I'll happily send you a brand new (ABB Part # ACS55-01E-02A2-2) 0.37KW / 1/2HP rated VFD if you got a motor to suit or even if you can get a motor easily  :beer: (I've got 1 or 2 from an old job)

I believe that anyone who is mad enough to build there own mill  :loco: deserves a little help  :thumbup:
:nrocks: sent a pm Jon thank you  :nrocks:
Title: Re: Another homemade milling machine
Post by: mexican jon on March 25, 2017, 09:58:45 PM
Replied to your PM  :clap:
Title: Re: Another homemade milling machine
Post by: shipto on March 26, 2017, 02:54:43 PM
Due to the limitations of my milling fixture on my lathe I couldn't mill out the opening for the pinion so in a blatent misuse of handtools I cut it out with the jigsaw. I have made the shaft for it and put some nasty bits of metal to hold it in place. The reason for them being so long is that they will provide a shoulder for aligning the shaft I did think about cleaning them up but it would have been a vanity operation because once the spindle housing is on they will be hidden.
Ignore the other misuse of tools the tap wrench was handy to turn it and it runs up and down reasonably well, bit of a tight spot but its probably better than most drilling machines out there and given time it should wear in nicely which will do given that it will only be used like this for drilling. During milling operations it will be locked up and the knee will provide the adjustment up and down.
Title: Re: Another homemade milling machine
Post by: sparky961 on March 26, 2017, 04:34:16 PM
Misuse, or ingenuity?  I'll argue for the latter.  It always takes more skill to get things done with only the tools at hand.

It's an interesting project and thread.  I look forward to seeing it progress.
Title: Re: Another homemade milling machine
Post by: awemawson on March 26, 2017, 04:39:25 PM
In the tradition of the early English tool makers, make the first one, then use it to help make the next - that as a progression, should be an improvement.

'tis has ever been thus  :clap:
Title: Re: Another homemade milling machine
Post by: shipto on March 30, 2017, 05:24:20 PM
I have made a bit of progress. keep having to stop myself messing with the slide and reminding myself just how sloppy most drilling machines are but anyway I made a start on the fixtures for the head first off I worked out where the studs go and put them in along with the mounting plates for the rest of the head.
These two plates will form the basis of everything else relating to the head. I have drilled and tapped for the adjusters which I have circled in red and as you can see I have plenty of adjustment to get the head lined up left to right \ | / if everything goes anywhere near right I wont need anywhere near as much adjustment as I have available.
I also took a pic of the X,Y table which seeing as this was done before I started the body I should have pictured before but anyway it has the base from a cheapo XY table that has been discussed on these forums before but I did some work on it and changed the screw to a 1mm pitch and it seems pretty good now. The other axis is bits from the very first lathe I had a clarke 300?? I will go into that in a bit more detail later in the thread.
Title: Re: Another homemade milling machine
Post by: shipto on March 31, 2017, 03:39:07 PM
got the bit together for the head drilled holes in them and used a bit of 12mm threaded bar to hold everything in place while I welded it all up. Just need to clean it all up tomorrow and maybe get the riffler on the corners because I forgot to leave room for a weld when I drilled the mounting holes.
Title: Re: Another homemade milling machine
Post by: shipto on April 01, 2017, 02:35:50 PM
Today I started on machining the head but I had to cut a extra bit out of it to fit to the four jaw chuck, just goes to show no matter what you have its not enough my 4 jaw is 10" and when I got it off my uncle I thought it would be plenty for anything I would ever want to do in fact I think I am going to have to resort to the 14" faceplate to machine for the bearing in the top.
If I had tried without cutting the extra bit out the chuck would have been as shown in pic 2, not good but took a action shot of the first drill 25mm and finally the end result is a space where the bearing and a oil seal I ordered today will sit.
Tomorrow I am going to attempt the hard job of lining it all up to do the top bearing as i said probably on the faceplate.
Title: Re: Another homemade milling machine
Post by: awemawson on April 01, 2017, 02:58:47 PM
In my experience NOTHING is big enough for everything you need to do - it's just the way of home shop workshops  :(

This is particularly true of floor area and shelf space  :lol:
Title: Re: Another homemade milling machine
Post by: shipto on April 02, 2017, 01:53:02 PM
I managed to get the other side lined up, machined and get the bearing shells fitted however after I had put the last one in I remembered something. I should have made a way to get them out again if I ever need to  :doh:
Too late now however so fingers crossed it all goes to plan or the head will have to be remade unless anyone has any ideas?
Now for the bit I have been dreading the spindle.
Title: Re: Another homemade milling machine
Post by: vintageandclassicrepairs on April 02, 2017, 02:18:40 PM
Hi Shipto,
A run of weld around the inside of the bearing rings will shrink them when they cool
the rings then usually fall out
That or tack a strap across the old race and drift from the far end

John
Title: Re: Another homemade milling machine
Post by: shipto on April 02, 2017, 02:24:30 PM
excellent suggestions John now I think about it a disc tacked to it would do great.
Title: Re: Another homemade milling machine
Post by: mexican jon on April 02, 2017, 04:44:12 PM
I"m with John  :scratch: on the run a bead of weld around the bearing shell and they just drop out  :ddb:
Title: Re: Another homemade milling machine
Post by: Houtenkrullen on April 06, 2017, 06:03:18 AM
Another option would be variable pulleys ala Daf variomatic ? also used on most modern mopeds
you would need to be able to control the movement of the pulleys rather than the centrifugal(?) mechanism used on them

If you are interested to use the moving pulleys idea, I am overhauling an old flott drill press that uses just that. I could send you a parts diagram and some pictures if they would be of any use for inspiration?

I am following your thread in awe...
I am not brave enough to start a machine build from scratch, but you seem to be doing just fine

Peter
Title: Re: Another homemade milling machine
Post by: shipto on April 06, 2017, 03:00:41 PM
Another option would be variable pulleys ala Daf variomatic ? also used on most modern mopeds
you would need to be able to control the movement of the pulleys rather than the centrifugal(?) mechanism used on them

If you are interested to use the moving pulleys idea, I am overhauling an old flott drill press that uses just that. I could send you a parts diagram and some pictures if they would be of any use for inspiration?

I am following your thread in awe...
I am not brave enough to start a machine build from scratch, but you seem to be doing just fine

Peter
Thank you for the offer Peter but I have a inverter coming thanks to Mexican Jon and so the machine will at least in the first place will be directly driven.
As for building the machine I just kept bits for ages before starting then jumped in two footed, I have made mistakes even in the very little I have done so far wait till you see the latest one which I will take pics of tomorrow actually not tomorrow me and wife are going to see mrs browns boys so saturday its a real  :doh:
Title: Re: Another homemade milling machine
Post by: shipto on April 09, 2017, 04:23:02 PM
Well here in pic1 is the latest mistake It wasnt till I had welded the flang on, cleaned it up and centered each side that I set it up and did a cut along the length and I noticed it had been cut half way through  :doh: cant even remember what I started to cut it for.

Well went back to my bits of steel and started again and pic 2 is the result. I am very pleased with it this is the first time I have cut a thread and made nuts to suit which is where I was at the end of today and apart from my parting tool of sorts breaking part way through meaning I had to finish it on the donkey saw even this went reasonably well.
I still have to clean up the nut and cut the lock nut off the bar which is the job for tomorrow.
Title: Re: Another homemade milling machine
Post by: hermetic on April 09, 2017, 05:10:20 PM
 Nice work Shipto!
Title: Re: Another homemade milling machine
Post by: shipto on April 10, 2017, 03:36:49 PM
So today I finished the nuts and gave the head a lick of paint, I chose black because, well its was either that or white no expence spent  :lol:
Title: Re: Another homemade milling machine
Post by: shipto on April 11, 2017, 04:45:38 PM
fitted the shaft and I am really chuffed with it rotated image so it in the right orientation just need to make a housing for the top seal but its got to have a channel for the grease nipple.
Title: Re: Another homemade milling machine
Post by: shipto on April 14, 2017, 03:28:40 PM
Seal housing is made and fitted and head is fitted to slide. Drilled the housing at a slight angle so the grease is delivered just under the lip of the seal.
Title: Re: Another homemade milling machine
Post by: krv3000 on April 14, 2017, 07:07:35 PM
shaping up nice
Title: Re: Another homemade milling machine
Post by: PekkaNF on April 15, 2017, 01:55:08 AM
Very interesting project. I'm cheking this one out every day!

I see you go exremes....but did you have to mount the lathe on the wall!

Pekka
Title: Re: Another homemade milling machine
Post by: shipto on April 15, 2017, 03:58:52 AM
 :lol: have you never heard of the Harrison 14 wall mount lathe?  :lol:
Actually I need to lock the head up to get it turned upright at the moment I am still trying to decide how to keep the head in the top position the options I have concidered so far are springs in various configurations, gas struts or probably my favourite right now counter balance system where some weight is connected over some pulleys to hang down at the back of the upright.
Any thoughts would be appreciated.
Title: Re: Another homemade milling machine
Post by: PekkaNF on April 15, 2017, 04:37:24 AM
Nope. First time ever. I swear.

About the counterbalance....that must work:
http://www.lathes.co.uk/elliott%20mini%20jig/index.html

Pekka
Title: Re: Another homemade milling machine
Post by: shipto on April 15, 2017, 05:43:43 AM
Nope. First time ever. I swear.

About the counterbalance....that must work:
http://www.lathes.co.uk/elliott%20mini%20jig/index.html

Pekka
Yes that one they have the weights inside the upright which is a good idea but may not be possible in mine due to the supports I have welded inside but maybe if I put a couple of tubes down the sides the weights could travel inside them  :coffee: still have to decide if I should fill the body with concrete yet however. The main upright is quite a substantial bit of box section with 5mm walls but it may still have some flex.
Actually another idea comes to mind I could just put a guard on the back to cover the weights and leave the inside clear.
Title: Re: Another homemade milling machine
Post by: kayzed1 on April 15, 2017, 04:47:28 PM
You could put the tubes down for the weights and then infill around them. :beer:
Title: Re: Another homemade milling machine
Post by: PekkaNF on April 16, 2017, 10:50:32 AM
.. :coffee: still have to decide if I should fill the body with concrete yet however. The main upright is quite a substantial bit of box section with 5mm walls but it may still have some flex.

Concrete sucks inside the steel shell...concrete shrinks and when it shrinks it delaminates from the skin fron that on it's just dead weight. If you consider that: read the Bamberg's paper.

It's all very good reading, but this is best short story I could find of it from interweb:
http://www.mech.utah.edu/~bamberg/research/ConcreteCastDamper/concreteCastDamper.html


Actually another idea comes to mind I could just put a guard on the back to cover the weights and leave the inside clear.

Best of all. You can can go trough iterations and finalize the weight.

Pekka
Title: Re: Another homemade milling machine
Post by: shipto on April 16, 2017, 05:53:39 PM
If thats the case I guess I am going to have to hope it doesnt need anything, that viscoelastic stuff looks complicated and probably expensive.
I wish I had put more diagonal supports in before I welded the bottom on now but I guess I am not going to know for sure until its up and running and making swarf.
Title: Re: Another homemade milling machine
Post by: DaveS on April 17, 2017, 05:47:15 AM
It's looking good Shipto :beer:
Counterbalance weights are a well tried and tested method and can be fine tuned but I would suggest using bicycle chain and not Brass machine's latest (and good looking chain mail)  :nrocks:

Dave
Title: Re: Another homemade milling machine
Post by: PK on April 17, 2017, 07:31:21 AM
Sorry if I'm restating something, I've come to this thread late (It must be outside this 'box' thing they keep telling me about)
Here's my take on a torsionally rigid mill column.
http://caswa.com/cncathome/X3.html
Scroll down about 2/3rds

I like the idea of filling with concrete. Adding mass is one of the simplest things you can do to a small machine to improve it.......

PK
Title: Re: Another homemade milling machine
Post by: shipto on April 17, 2017, 05:36:02 PM


I like the idea of filling with concrete. Adding mass is one of the simplest things you can do to a small machine to improve it.......

PK
I do too but Pekka disagrees and I see his point about shrinkage. However upon doing some extra reading it seems that most of the shrinkage comes from adding more water than is needed to make the concrete move better it seems that if the added water is calculated correctly then little shrinkage occurs but the mix is extremely thick. Will have to look into it a bit more.
Title: Re: Another homemade milling machine
Post by: vintageandclassicrepairs on April 17, 2017, 06:38:16 PM
Hi Shipto,
Research "epoxy" concrete as a filler,
There was a long discussion on it on the CNC forum some years ago

John
Title: Re: Another homemade milling machine
Post by: AdeV on April 18, 2017, 12:05:28 AM
Since it's only the weight you're after, and not the constructional qualities, why not just use a bag of sand? Seal the bottom as best you can, but leave a removable panel; pour sand in the top until desired weight is achieved - it'll find its own way past the internal structures obviously. Then, when you need to move the machine at a later date you can simply open the removable panel and let the sand out...

The only thing you need to be sure of is that the sand is bone dry before you pour it in, wet sand will cause untold rustiness...
Title: Re: Another homemade milling machine
Post by: awemawson on April 18, 2017, 02:18:34 AM
If it's a closed box structure i.e. No holes for stuff to flow out, dry sand or pea shingle will work just as effectively as concrete, and will settle into a dense packing over time. Also in extremiss it can be removed if you make a suitable plugged hole in the base.
Title: Re: Another homemade milling machine
Post by: PekkaNF on April 18, 2017, 03:26:57 AM


I like the idea of filling with concrete. Adding mass is one of the simplest things you can do to a small machine to improve it.......

PK
I do too but Pekka disagrees and I see his point about shrinkage. However upon doing some extra reading it seems that most of the shrinkage comes from adding more water than is needed to make the concrete move better it seems that if the added water is calculated correctly then little shrinkage occurs but the mix is extremely thick. Will have to look into it a bit more.

The thing is that concrete shrinks for 400 years. First faster and then slower. Many factors affect on shrink rate and some you have influence and some not.

Worst shape for concrete "filled machine" is a hollow thin steel section that you fill with concrete...some machine manufacturers tried this -70/80:s and failed. Concrete filling will shrink in time and delaminate from the skin...if you weld rebar to avoid that it will pull the skin out of alingnment. There are ways to reduce the shrink rate or compensate it, but it will not work in machine building scale.

You can make a servisable machine if you know what you are doing. Basically you cast more or less square section, no voids in it, you may cast some features to it. You don't need rebar and other "iron" on it, unless you have hanging beam or such bad idea. And then let it cure and age some time - longer the better. Then use this cast as a sandwitch between steel members and have it on compression. You must use epoxy concrete, injection epoxy or grind the concrete surface flat prior mechanically mounting the steel sructure to it.

Epoxy concrete works.

And as Andrew et.al. said sand or such will dampen "ringing" pretty well too, it's cheap, reversible and has all good qualities to home build.

Pekka
Title: Re: Another homemade milling machine
Post by: shipto on April 18, 2017, 05:13:57 AM
What about a dry mix? www.precast.org

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Title: Re: Another homemade milling machine
Post by: awemawson on April 18, 2017, 05:38:13 AM
It will eventually harden from moisture in the air and you'll lose the advantage of being able to remove it.
Title: Re: Another homemade milling machine
Post by: shipto on April 18, 2017, 06:07:15 AM
Won't want to removed it there's nothing I need to do from inside. The only advantage of being able to remove it would be weight but once it's in place it would be my kids job to get rid of it 😃

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Title: Re: Another homemade milling machine
Post by: mattinker on April 18, 2017, 06:32:14 AM
If you want weight only, lead!

Regards, Matthew
Title: Re: Another homemade milling machine
Post by: shipto on April 18, 2017, 06:42:16 AM
It's not just weight it's helping rigidity too. However as I have said I won't make a decision until it's running and I have tested to see if it's needed, fingers crossed it won't need anything extra.

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Title: Re: Another homemade milling machine
Post by: PK on April 18, 2017, 06:49:35 AM
If you want weight only, lead!
In my experience....

Mass is the main advantage. Particularly on a small machine as it reduces the resonant frequency of the structure below the excitation frequency of the spindle+tooth count combination. 
This resonance (and some terrible engineering in the case of the X3 mills) is what causes the most grief, and it's why the 20KRPM Chinese spindles for chump change have revolutionised the CNC router business. They increase the excitation frequency above the resonant frequency of even the tiniest mill

But there are others.  When the structure is made up of parts of different densities, a portion of energy that travels through it as waves (rather than displacement/vibration) is reflected at each interface. This forces a portion of these waves to travel long paths and get absorbed by the substrate.
Title: Re: Another homemade milling machine
Post by: awemawson on April 18, 2017, 07:53:09 AM
Blimey PK that's a bit impressively technical  :bow:
Title: Re: Another homemade milling machine
Post by: PK on April 18, 2017, 09:26:04 AM
Blimey PK that's a bit impressively technical  :bow:
Yeah, sorry 'bout that. It was a big chunk of my PhD.... Buy me two beers and I can bore you to death with the numbers... Oh, and I've had two beers......
Title: Re: Another homemade milling machine
Post by: PekkaNF on April 18, 2017, 10:15:38 AM
Blimey PK that's a bit impressively technical  :bow:
Yeah, sorry 'bout that. It was a big chunk of my PhD.... Buy me two beers and I can bore you to death with the numbers... Oh, and I've had two beers......

By all means. I'll get you drunk. Please tell more! I used go on trips with one professor, we hooked acceleration sensors and other transduces to measure vibration and find out excitation sources/sympathic frequences. Laymen had no idea how involved in real life it is.

And granules are different animals. We measured some of them too in one big machine...Big beam filled with sand or glassballs...So, which one is "better"? it all depends what is your question.

So...all this is pretty basic (from post #44):
http://www.mech.utah.edu/~bamberg/research/ConcreteCastDamper/concreteCastDamper.html

Everyone seriously considering should least read this:
https://pdfs.semanticscholar.org/5487/82f4c63376150991dd323d0ef15a7da2fee8.pdf

At this phase of this project it's all pretty academic and best to forge forward.

Pekka
Title: Re: Another homemade milling machine
Post by: shipto on April 18, 2017, 01:28:29 PM

At this phase of this project it's all pretty academic and best to forge forward.

Pekka
I agree I didnt intend it to get this much of a discussion its more a "what if" situtation at the moment I could get it set up and it runs like a dream or it could be so bad that I scrap all but the expensive bits and not even want to waste a bag of cement. I hope it the first option  :lol:
Title: Re: Another homemade milling machine
Post by: shipto on April 23, 2017, 04:28:47 PM
So I have now turned my attention to the knee slides and in yet another operation that would have been done better with a mill I made 4 elongated slots in each and made some blocks to help me get them lined up straight and keep them there. I have decided that I will get one side lined up as best as I can to the column and pin it, then everything will be lined up to that.
Title: Re: Another homemade milling machine
Post by: shipto on April 27, 2017, 05:24:39 PM
The knee is going to have to go back to the drawing board (what theres a drawing board?) at the very least temporarily as the bits are nowhere near straight I suspect its down to the rubbish jig I made to mill them on the lathe. So I am thinking of borrowing ideas from the gingery lathe and make the ways and carriage from some bright drawn stock which will hopefully get me running the mill well enough to straighten up the cast iron bits. Finger crossed.

Nearly had a major oops moment tonight while try to move the carriage along I pushed a little too hard and dropped it amazing how fast you move when your feet are in danger  :lol: that will teach me to secure it before messing.
Title: Re: Another homemade milling machine
Post by: tom osselton on April 28, 2017, 01:05:43 AM
Yep watch them toes!
Title: Re: Another homemade milling machine
Post by: shipto on April 28, 2017, 07:35:11 AM
I do wear steel toecap boots but I doubt they would have helped the rest of my foot.

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Title: Re: Another homemade milling machine
Post by: vtsteam on April 30, 2017, 09:52:25 AM
Back for a visit, and a great project. I keep skipping over theory and advice posts, Dwayne, to settle on the best part of a build, the build itself! Keep on truckin' buddy, yer doin' great!  :clap: :clap: :clap: :clap:
Title: Re: Another homemade milling machine
Post by: shipto on April 30, 2017, 05:32:26 PM
Thanks Vtsteam
This project is going to take a little detour now in terms of the column, up until I got my Harrison I was using a past its best Drummond round bed with a broken head casting, this has been stuck under the bench slowly getting covered in various bit and pieces.
While sat in shed talking to my mate about the problems with the knee slide and how I was going to have to get something rigged up to sort them out properly it suddenly came to mind.
So I dragged it out and we sat there some more making plans and it is going to be used for the time being, this way I will have a milling machine hopefully capable of allowing me to make the origional design much better.
Title: Re: Another homemade milling machine
Post by: shipto on May 01, 2017, 02:46:01 PM
It almost feels like I should be showing this on a new thread but I guess I can get away with it.

So a bit of 76X38 channel is a good size to sit across the round bed from the Drummond, the main thing about this detour is to not damage the Drummond bed as I have other plans for it. I welded four bolts to the sides of the channel and cut some bit to clamp the channel, on the bottom clamp is a piece which will make sure the bed will not break under stress and also ensure the head will not move.

Next I bolted the head slide onto the 76X38 channel (which I didnt take a pic of) and fitted the head so as you can see I am still going to have both the head and the knee moveable.
Title: Re: Another homemade milling machine
Post by: vtsteam on May 01, 2017, 07:53:37 PM
Improvisation, and making one tool to make another is the name of our game, Dwayne! Looking forward to seeing how this will come together.  :beer:
Title: Re: Another homemade milling machine
Post by: shipto on May 02, 2017, 05:20:27 PM
Made the base while at work today and fitted the column to it tonight. I could do with a decent square as it seems a tad off but I cant be sure my set square is accurate, however there is one major problem with the 76x38 when its tight it is spreading around the bed at the bottom but not at the top so the head is being taken off square so I either need to use something better or weld something in to stop the bottom spreading.
In pic 3 I show the table in about the position it will be on the knee and the hole in the base is where I am planning to put the lifting screw for the Z axis, I would welcome opinions on wether I should move that forward nearer to the center of the travel? my first thoughts where that the screw should be reasonably close to the column to ensure the knee would move smoothly but I am not too sure now.
Title: Re: Another homemade milling machine
Post by: vtsteam on May 02, 2017, 05:36:09 PM
I'd vote for the center of the X and Y travels on their slide ways should be under the axis of the head spindle. And the Z screw also under that point.
Title: Re: Another homemade milling machine
Post by: vtsteam on May 02, 2017, 05:41:36 PM
With regard to the channel guide on the head, maybe I might try adding two small plates welded to form a Vee inside the channel legs, so the pillar now slides against that Vee. Each plate would weld to a leg, and to the channel center line, inside.
Title: Re: Another homemade milling machine
Post by: shipto on May 03, 2017, 06:52:49 AM
The center of the X and Y will be under the spindle axis to maximise the cutting area. Looking at most of the milling machines on a Google image search shows me manufacturers don't seem to have any rules regarding the position of the lift screw. However my machine is no where near the weights they are dealing with so under the spindle axis seems reasonable to me too. As for the head I think I am going to trap a block between the column and the channel for now and sort it out properly later. Now it is annoying me as the plan for the Drummond bed was to one day make it into a decent and saleable lathe again but I am liking the way this is going so much that it's unlikely I will change it now. So sorry to anyone who was following me while I wasted time up to now.

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Title: Re: Another homemade milling machine
Post by: shipto on May 03, 2017, 06:56:18 AM
Sorry hit send before I finished:
This being the case I can now look at modifying the head casting to take the milling head once the machine is working reasonably well.

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Title: Re: Another homemade milling machine
Post by: mexican jon on May 03, 2017, 10:23:01 AM
Made the base while at work today and fitted the column to it tonight. I could do with a decent square as it seems a tad off but I cant be sure my set square is accurate, however there is one major problem with the 76x38 when its tight it is spreading around the bed at the bottom but not at the top so the head is being taken off square so I either need to use something better or weld something in to stop the bottom spreading.
In pic 3 I show the table in about the position it will be on the knee and the hole in the base is where I am planning to put the lifting screw for the Z axis, I would welcome opinions on wether I should move that forward nearer to the center of the travel? my first thoughts where that the screw should be reasonably close to the column to ensure the knee would move smoothly but I am not too sure now.

I've got some spare spare round bed castings if it would help with the mounting of the head ??? yours for postage? just checked and there is a bed as well  :headbang:
Title: Re: Another homemade milling machine
Post by: shipto on May 03, 2017, 11:22:22 AM
Thank you Jon but I have the castings

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Title: Re: Another homemade milling machine
Post by: shipto on May 03, 2017, 03:18:40 PM
 :ddb: I am happy now because I put the knee on and did some clocking, with a tool in the collet and everything tightened up I got .07mm twisting it from side to side not sure how that compares to other small millers but it seems pretty good to me and it should improve once I get the origional head casting sorted rather than the bit of channel the best bit though was from the knee to the column and putting weight on the knee I got .01 if you want to be picky .02 but that was a lot of pressure.
Sorry Vtsteam but it seems my gut feeling on the position of the lift screw was correct I thought I would test with a jack and on center it locks up on the column I could move it forward a little but since I have already drilled the hole I will stick with that.
Tomorrow I will cut some bits of tube to mount the motor.
Title: Re: Another homemade milling machine
Post by: vtsteam on May 03, 2017, 03:23:08 PM
Sorry Vtsteam but it seems my gut feeling on the position of the lift screw was correct I thought I would test with a jack and on center it locks up on the column I could move it forward a little but since I have already drilled the hole I will stick with that.

No need for apology, it's important that the knee actually be able to slide on a mill! :lol:
Title: Re: Another homemade milling machine
Post by: shipto on May 04, 2017, 05:31:27 PM
This is where the motor will sit just need a coupler.
Title: Re: Another homemade milling machine
Post by: shipto on May 06, 2017, 03:45:51 PM
Made the coupling and fitted it but needed to have a bit more height even had it running so I am a happy almost mill owner  :ddb:
Title: Re: Another homemade milling machine
Post by: shipto on May 07, 2017, 02:09:40 PM
Well it has made its first cut which was for mounting some cross pieces ready for the bed bits.
Title: Re: Another homemade milling machine
Post by: awemawson on May 07, 2017, 02:11:47 PM
Excellent!

All the old tool makers in the Whitworth / Maudsley era made a machine and used the machine to make better machines ad infinitum, and now you're on the same track  :ddb:
Title: Re: Another homemade milling machine
Post by: vtsteam on May 07, 2017, 02:28:42 PM
Yes but remember, the first cut is the deepest. :hammer:

Congrats Dwayne!! :thumbup: :clap: :beer:
Title: Re: Another homemade milling machine
Post by: shipto on May 07, 2017, 03:18:18 PM
Thank you both
Yes but remember, the first cut is the deepest. :hammer:
I hope not VT  :lol: I was taking it easy with these cuts as the X axis hasnt got the screw fitted yet I was relying locking up the gib to keep it in place having said that it cut very well and I probably could have taken deeper cuts.
Title: Re: Another homemade milling machine
Post by: howsitwork? on May 07, 2017, 03:39:38 PM
Well done :thumbup:
Title: Re: Another homemade milling machine
Post by: shipto on May 08, 2017, 08:56:04 AM
Yes but remember, the first cut is the deepest. :hammer:

Congrats Dwayne!! :clap:
Grrrrrr I have that bloody song going through my head all day. Thanks Vtsteam

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Title: Re: Another homemade milling machine
Post by: Fredbare on May 08, 2017, 12:38:14 PM
Well done Shipto, been following this with great interest. Thanks for sharing.

John

Title: Re: Another homemade milling machine
Post by: tom osselton on May 08, 2017, 04:12:16 PM
Yes but remember, the first cut is the deepest. :hammer:

Congrats Dwayne!! :clap:
Grrrrrr I have that bloody song going through my head all day. Thanks Vtsteam

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Try this one!
She's got a lovely set of coconuts!
Title: Re: Another homemade milling machine
Post by: vtsteam on May 08, 2017, 07:21:58 PM
Put de lime in it.  :lol:
Title: Re: Another homemade milling machine
Post by: shipto on May 09, 2017, 03:07:13 AM
I'm not listening 😂

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Title: Re: Another homemade milling machine
Post by: shipto on May 10, 2017, 05:10:56 PM
I have all the supports in place but while using the machine I found it impossible to find the right place for the lifting screw (well jack at the moment) too far forward and it lifts the front and locks up on the column on the way up too far back and it locks up on the way down there is a sweet spot but obviously this changes when you move the Y axis.
So during a repetative drilling job at work I started to think about it and looked at the column on the drill which has a big lump of cast iron hanging from a round column much like the mill and the lifting mechanism is part of the casting so I am going to see if putting the screw back in the place that Drummond intended it to be will solve the problem.
I need to slightly redesign the bottom a little as the hole that the screw will need to go through is being used to secure the column. With this in mind I dug out a bearing housing which will make a support for the bottom of the column.
Title: Re: Another homemade milling machine
Post by: vtsteam on May 11, 2017, 08:34:44 PM
Longer bearing on the column would prevent locking. But that would reduce the lift range.
Title: Re: Another homemade milling machine
Post by: shipto on May 12, 2017, 04:24:32 AM
Yes if moving screw to inside doesn't help I can machine the Drummond tail stock to bolt it onto the knee which will add just short of 2 inches and if I put it at the top it won't effect travel.

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Title: Re: Another homemade milling machine
Post by: shipto on May 14, 2017, 04:34:05 PM
Busy weekend not just with the mill but found time to get some things sorted I bored out the old bearing housing and added it as support for the bottom of the column also opened out the origional holes and tapped them to M10 so it should be secure enough. I have the handle for the screw located at the top for now which will be a pain in the backside to use but one of the first jobs once table is finished will be to make a couple of bevel gears with a 2.5:1 ratio to match the M20 screw. I am pleased to say however that it seems to work well with the screw inside the column sorry pic is a bit dark.
On the subject of the table I got a temporary end plate made so I can use it to start milling the bits for the table and in the meantime I need to find a local tin basher to make a tray.
Title: Re: Another homemade milling machine
Post by: shipto on May 15, 2017, 02:27:58 PM
Realised tonight while drilling holes for bed parts there is a bonus to having the screw inside the column  :D I can rotate the knee and reach past the end of the table, not sure I will ever have a use for the capability but still.
Title: Re: Another homemade milling machine
Post by: shipto on May 16, 2017, 03:08:25 PM
I am really happy with it now, started to mill for the T slots and apart from a little mishap where I hadnt locked the rotation up it cuts lovely
Title: Re: Another homemade milling machine
Post by: shipto on May 17, 2017, 03:29:28 PM
Have two of the three parts for the bed milled now, it did show up a problem for me to fix under the bed casting the nut is trapped and was held in place with a m4 grub screw which turned out not to be man enough for the job so it was replaced with two m6 grub screws one to hold and another to lock. I suspect that the X/Y table will not last too long guess I better put a axminster or similar one on my Christmas list.
Title: Re: Another homemade milling machine
Post by: shipto on May 19, 2017, 03:20:05 PM
Table is together and hopefully tray is in hand very soon. Replaced the gib screws on the X axis from 4mm to 5mm and put a bit of scrap aluminium on it to test the squareness of the X to Y and I think it is slightly out but not too much that I cant fix when it becomes a problem.
Title: Re: Another homemade milling machine
Post by: shipto on May 28, 2017, 03:44:52 PM
Milling machine is at a bit of a stand still in terms of making bits for it but I have been working with it to finish a qctp I started on the lathe and abandoned when the lathe wrecked the dovetail cutter I had.
Just need to make some handles for it now and it will be ready for me to start making holders for it.
Title: Re: Another homemade milling machine
Post by: vtsteam on May 28, 2017, 09:18:02 PM
Looks like you have yourself a mill! :thumbup: :beer:
Title: Re: Another homemade milling machine
Post by: shipto on May 29, 2017, 04:12:48 PM
I wont go quite that far yet still have quite a bit to do before I will say its a proper mill. It does however look promising and is producing some nice cuts even with the not so good cutters I have. I knocked up a fly cutter which is responsible for most of the surfaces on the qctp its not pretty but it works very well.
If anyone could point me in the right direction to order a couple of bevel gears for a nice price I would be very interested I did consider using some out of angle grinders I have collected over the years but they are such weird ratio's like 3.5454545:1 etc the nearest I have found to a proper ratio is 3.9:1 so far. I would like either 2.5:1 or 5:1.
Title: Re: Another homemade milling machine
Post by: shipto on July 15, 2017, 05:35:20 PM
Despite me being quiet on this thread I have still been doing things for and with the milling machine I am now at the point where I am moving the z axis handle from the top of the mill at the back to the bottom at the front.
After much searching for some gears of the correct ratio I gave up and decided to use some of the gears I salvaged from a old angle grinder which have a ratio of 3.9:1 not much use for graduating the handle with the 2.5mm pitch screw but its gonna have to do.
When I finished today I had what is shown in the picture just need to make sure the screw is nice and square tomorrow before I drill and tap to mount it.
Title: Re: Another homemade milling machine
Post by: vtsteam on July 15, 2017, 09:57:13 PM
Great to hear, and see that you're continuing to progress with it!

Maybe some day, cut some bevel gears with it in the ratio you want......?  :dremel: :beer:
Title: Re: Another homemade milling machine
Post by: shipto on July 16, 2017, 08:11:07 AM
Great to hear, and see that you're continuing to progress with it!

Maybe some day, cut some bevel gears with it in the ratio you want......?  :dremel: :beer:
Thats certainly one option but I am edging towards leaving the knee as is and using the z axis on the spindle as the measurable part.