Author Topic: DRO questions  (Read 41008 times)

Offline j45on

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DRO questions
« on: February 18, 2011, 03:00:25 PM »
Sorry guys I have lots of daft questions

I would really like to add a digital readout to my mini mill (Axminster sieg x2)  :proj:
I have been looking at this http://www.machine-dro.co.uk/index.php?target=products&product_id=111
But I am unsure if they have scales small enough for my mill and it might cost as much as my mill  :(

My other option is the chinese scale option with remote readouts from Arc euro (very bottom of page) http://www.arceurotrade.co.uk/Catalogue/Measurement/Digital-Readouts
Does anybody use the Arc digital readouts ? do they enable fast readout from the scales ?
This might be my favourite as I can add scales as I can afford them

I also found these on ebay but can not find them in Europe http://cgi.ebay.co.uk/XYZ-3-AXIS-DIGITAL-QUILL-READOUT-DISPLAY-SCALE-DRO-SET-/300379046832?pt=LH_DefaultDomain_0&hash=item45effc83b0#ht_4693wt_907

I have the fignoogle plans but I plan to add the scales to the rear of the x axis and on the left of the y axis to keep them away from the gib adjuster and locking levers
« Last Edit: February 18, 2011, 03:02:03 PM by j45on »
Jason

Offline kwackers

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Re: DRO questions
« Reply #1 on: February 18, 2011, 03:40:25 PM »
The readouts you've posted too are simply extensions of the display on Chinese type scales.

The nice thing about a 'proper' DRO is that it lets you do all sorts of nice things, PCD drilling etc.
The machine DRO system is good but only works with glass scales - so around £100 an axis, you can use magnetic scales also which are much smaller but probably nearer £160 an axis. OTOH, Chinese scales can be as little as a fiver for a modified caliper...

Another option you haven't mentioned is a Shumatech DRO. In the UK these are available from http://medw.co.uk/wiki/index.php?page=Shumatech+DRO350.
The beauty of the Shumatech is that it can read both Chinese and glass scales or a mixture of the two. The basic model is the 350, but if you're getting one from scratch you may as well consider the 550 (either the 350 with a DPU550 upgrade or a DRO550).
It's also incredibly functional and if you can be bothered you can modify the open source software (I changed it to allow fractions to be entered directly).
On my mill I use the 550 to read 3 glass and one chinese scale.

Offline j45on

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Re: DRO questions
« Reply #2 on: February 18, 2011, 04:35:23 PM »
Cheers Kwackers  :thumbup:
I forgot the Shumatech I had looked into it a bit a while ago and thought the DRO-550 was not made anymore  :scratch:

I had discounted the DRO-350 because it was the same price as a ready made unit from machine dro
which makes no sense now when I think about it as it can use cheaper scales and I enjoy building kits  :doh:

Before I go and order a DRO-350 can anyone shed any light on the availability of the DRO-550.
I am sure I read somewhere that the guy does not make them anymore ?
Jason

Offline kwackers

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Re: DRO questions
« Reply #3 on: February 18, 2011, 04:58:57 PM »
The 550 is currently "out of stock", this is due to Scott not being able to obtain the processors. However I believe these are becoming available and so there should be some movement on these shortly.
Best to look on the Shumatech site for details - or better join the Yahoo Shumatech group. Worth downloading the manual and having a look anyway.

Don't discount building a 350 plus a DPU550 upgrade, the only real difference is the DRO550 can also have the LCD module attached (if you really need one). Also don't discount just using the basic 350, not quite the same features as the 550 and doesn't support as many variations of Chinese scales than the 550 but may be all you need and if you need to at some time in the future you an just add a DPU550 upgrade (plugin board that drops in place of the processor).

The DRO550 when it becomes available will need to be ordered directly from the states as its sold at cost so no point in Lester importing them.
I have 3 DRO550's, 1 on my mill, 1 on my lathe and 1 for development (I play around with writing software for it - one of my intentions when I get a bit of time is to add a basic rotary controller to it). I think its a great bit of kit and has an excellent (and expanding) feature set.
« Last Edit: February 18, 2011, 05:01:13 PM by kwackers »

Offline Bogstandard

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Re: DRO questions
« Reply #4 on: February 18, 2011, 05:01:16 PM »
Jason,

I think this might be the info you are after

http://medw.co.uk/wiki/index.php?page=ShumatechEuropeanPrices


BTW, personally I would forget the scale types for low down on a mill, they are forever breaking down. I spent a fortune keeping mine going, and eventually spent so much I could have bought a top of the range glass scale type. They are OK for up on the quill.


John
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Offline NickG

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Re: DRO questions
« Reply #5 on: February 18, 2011, 05:56:29 PM »
Jason,

I had the same dilemma - I was going to go with the sliding cheapo chinese type scales but have been put off, batteries, swarf, oil ingress etc and they just aren't as accurate. So I've saved (no, well I haven't spent money) up for the glass scales and a DRO like the one in your first link.

Nick
Location: County Durham (North East England)

tumutbound

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Re: DRO questions
« Reply #6 on: February 18, 2011, 05:57:46 PM »
I have a   DRO-350 with DPU-550 installed on my X2 mill.
Scales are the low cost Chinese ones, in my case from Shars.
I modified the scales to remove the batteries and most of the unnecessary components

FWIW, the Shumatech group has a post about a new run of DRO-550s now that the processors are available.
« Last Edit: February 18, 2011, 05:59:23 PM by tumutbound »

Offline j45on

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Re: DRO questions
« Reply #7 on: February 18, 2011, 07:47:57 PM »
Cheers for all your input guys  :beer:

Mmmm decisions decisions  :scratch:

I'm going to think about this a bit more and do some more homework and have a good measure of my mill
work out some costs and pros and cons ect ect
Jason

Offline kwackers

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Re: DRO questions
« Reply #8 on: February 19, 2011, 05:34:49 AM »
I ran a 30 inch and 8 inch Chinese scale on my lathe for around 5 years with my 350 and it worked a treat.
I made covers for both and for the saddle made a 'U' shaped bracket to drive the head so that swarf and crap couldn't find it's way onto it.
Never had any problems (left the original batteries in too).

However I didn't use coolant (other than 'brushed on') so can't say how well they'd hold up but whatever the scale you need to protect it against ingress of coolant and swarf.

When I replaced my lathe I moved to glass scales. They're definitely 'better', no jitter etc. For my cross slide I used a magnetic scale which is excellent since it doesn't steal space. I'm thinking about replacing the X axis on my mill with a magnetic one, mainly because it would fit inside the casting of the bed and so I'd lose no Y movement, at the moment I lose around 1 inch with a slimline glass scale (and cover).
However using the 550 means I have a cheap Chinese scale on the quill which can be set to sum with the Z axis.

The 550 also includes edge detection and RPM reading (with suitable sensors), if you include the LCD unit it has a memory card slot which should in future be able to take a file with a list of points or operations - ideal for drilling loco side frames etc. This is work in progress though, I've been doing some stuff on it but currently am stuck for time. Not sure what other work is under way.



Offline HS93

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Re: DRO questions
« Reply #9 on: February 19, 2011, 06:13:52 AM »
I ran a 30 inch and 8 inch Chinese scale on my lathe for around 5 years with my 350 and it worked a treat.
I made covers for both and for the saddle made a 'U' shaped bracket to drive the head so that swarf and crap couldn't find it's way onto it.
Never had any problems (left the original batteries in too).

However I didn't use coolant (other than 'brushed on') so can't say how well they'd hold up but whatever the scale you need to protect it against ingress of coolant and swarf.

When I replaced my lathe I moved to glass scales. They're definitely 'better', no jitter etc. For my cross slide I used a magnetic scale which is excellent since it doesn't steal space. I'm thinking about replacing the X axis on my mill with a magnetic one, mainly because it would fit inside the casting of the bed and so I'd lose no Y movement, at the moment I lose around 1 inch with a slimline glass scale (and cover).
However using the 550 means I have a cheap Chinese scale on the quill which can be set to sum with the Z axis.

The 550 also includes edge detection and RPM reading (with suitable sensors), if you include the LCD unit it has a memory card slot which should in future be able to take a file with a list of points or operations - ideal for drilling loco side frames etc. This is work in progress though, I've been doing some stuff on it but currently am stuck for time. Not sure what other work is under way.



as you have used them does swarf stick to the slides as they are magnetic? or are they very weak and cause no problemss

thanks

peter
I am usless at metalwork, Oh and cannot spell either . failure

Offline kwackers

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Re: DRO questions
« Reply #10 on: February 19, 2011, 07:03:32 AM »
as you have used them does swarf stick to the slides as they are magnetic? or are they very weak and cause no problemss

thanks

peter
It does a bit, as in the magnet is strong enough to attract some of the smaller bits but not so strong they're not easily brushed off.
Ideally a small piece of felt as a wiper on the read head is all you need (something I need to do).

Offline z3t4

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Re: DRO questions
« Reply #11 on: February 19, 2011, 10:21:50 AM »
Hi Jason

I've used Scott Shumate's DRO 350 (on an ml7 with glass scales from Allendale, who are great) and a DRO 550 with hacked caliper scales on a mill.
I wouldn't just use the caliper scales 'as-is' because they would constantly be whinging about swarf and coolant. They need to be wrapped up nice and comfy just like the glass scale heads are, so the heads need to be removed from the case and LCD, then supported in a carrier (I used Delrin) which holds it at the right separation from the scale and protects it from swarf etc. Finally the scale needs to be protected against swarf and coolant.

To keep costs down I used the replacement caliper heads from china (virtual village, < a fiver each) and Wixey tablesaw DRO tape for the caliper track, mounted on ally extrusion. The DRO 550 is an excellent bit of kit. Scott developed it as a labour of love and there was so much interest on the Yahoo group that he ended up getting a load of 4-layer SMD boards made and organised a group buy. It's not a commercial product. The deal is you get your DRO board and kit for about £150 including post and customs robbery, Scott makes nothing on it (unless you choose to leave him a donation, which I think nearly everybody did) but if the boat sinks or you fry the board or it's lost in transit, then it's your problem, not his. Some children failed to understand this.

I see on the Shumatech Yahoo group that the microprocessor that he uses is likely to be available again soon, so probably he will be ordering another group buy. If I wanted another DRO I'd be getting my name down on the group buy list.

HTH

Regards,

John

Offline j45on

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Re: DRO questions
« Reply #12 on: February 19, 2011, 02:21:08 PM »
I have had a quick add up and a DRO-350 with cables and scales ect comes to around £315.

A machine-dro read out with glass scales to fit my mini mill comes to £542 which is £100 more than my mill cost new I cant justify that for my use.

I have had an email from ShumaTech informing me that the DRO-550 is available for pre order with an estimated mid-March ship date.
Jason

Offline raynerd

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Re: DRO questions
« Reply #13 on: February 19, 2011, 02:40:24 PM »
Jason, I have the Shumatech 350 (Kwacks old one) and although I mucked up one readout with swarf, I`ve not had any problems since covering them up. I planned a lovely plastic moulded cover but ended up with a piece of thin ally which has done the job no issues.

Just curious, if you put the X-axis readout at the back of the table, will you not lose some Y travel?  Just a thought. I`m actually interested because it does get in the way a little with the axis locking nut.

Chris

Offline kwackers

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Re: DRO questions
« Reply #14 on: February 19, 2011, 02:53:20 PM »
I don't think there's a whole lot of difference in the prices of the consoles, iirc the 550 runs to around £130 if you get a pre cut box and made up cables. The basic unit without box and cables is about £80 so there's some money to be saved there if you make the cables yourself and find a suitable box.

The main advantage of the 550 is you can start with Chinese scales and upgrade to glass at any point (if ever). I also think the functionality of the 550 is somewhat better than the commercial units and currently only around 10% of the ROM is used so there's a lot of scope for extras.

I must admit to being a huge fan of DRO's. They make things so much easier...

Offline j45on

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Re: DRO questions
« Reply #15 on: February 19, 2011, 02:56:39 PM »
Chris
I was hoping to squeeze a small scale and diy aluminium cover in there on the rear of the x axis  :dremel:
I might lose 10mm of y travel but it would keep the scale away from the gib adjusters and mainly the locking screw.
Well that was my plan anyway  :lol:

EDIT I have pre ordered a DRO-550 board Thanks for the advise guys  :beer:  :nrocks:
As for scales I have not decided yet but I have a while to consider my options.
« Last Edit: February 19, 2011, 03:27:14 PM by j45on »
Jason

Offline j45on

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Re: DRO questions
« Reply #16 on: February 19, 2011, 04:23:11 PM »
Hi Jason

I've used Scott Shumate's DRO 350 (on an ml7 with glass scales from Allendale, who are great) and a DRO 550 with hacked caliper scales on a mill.
I wouldn't just use the caliper scales 'as-is' because they would constantly be whinging about swarf and coolant. They need to be wrapped up nice and comfy just like the glass scale heads are, so the heads need to be removed from the case and LCD, then supported in a carrier (I used Delrin) which holds it at the right separation from the scale and protects it from swarf etc. Finally the scale needs to be protected against swarf and coolant.

To keep costs down I used the replacement caliper heads from china (virtual village, < a fiver each) and Wixey tablesaw DRO tape for the caliper track, mounted on ally extrusion. The DRO 550 is an excellent bit of kit. Scott developed it as a labour of love and there was so much interest on the Yahoo group that he ended up getting a load of 4-layer SMD boards made and organised a group buy. It's not a commercial product. The deal is you get your DRO board and kit for about £150 including post and customs robbery, Scott makes nothing on it (unless you choose to leave him a donation, which I think nearly everybody did) but if the boat sinks or you fry the board or it's lost in transit, then it's your problem, not his. Some children failed to understand this.

I see on the Shumatech Yahoo group that the microprocessor that he uses is likely to be available again soon, so probably he will be ordering another group buy. If I wanted another DRO I'd be getting my name down on the group buy list.

HTH

Regards,

John


Hi z3t4  John
I would love to see some pictures of your scales  :worthless:
Did you get your "Wixey tablesaw DRO tape" from the UK ?
Jason

Offline picclock

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Re: DRO questions
« Reply #17 on: February 20, 2011, 04:54:27 AM »
@zt34

>>To keep costs down I used the replacement caliper heads from china (virtual village, < a fiver each)

Do you have a link for them ?. I broke the glass on my 30" ones when something slipped  :(

Made a new one out of plastic from a cd case but would quite like to replace it.

Apart from the remote readout what other useful functions do the shumatech boards offer ?

Best Regards

picclock
Engaged in the art of turning large pieces of useful material into ever smaller pieces of (s)crap. (Ferndown, Dorset)

Offline kwackers

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Re: DRO questions
« Reply #18 on: February 20, 2011, 06:16:59 AM »
Hi Picclock,

Probably best to have a scan of the user manual.
http://www.shumatech.com/web/products/opendro/guide

Offline j45on

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Re: DRO questions
« Reply #19 on: February 20, 2011, 07:39:05 AM »
Picclock try here http://www.virtualvillage.co.uk/callipers-and-precision-tools
they seem to be out of the cheep ones
Jason

Offline John Stevenson

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Re: DRO questions
« Reply #20 on: February 20, 2011, 08:13:14 AM »
I reckon I have a spare built up DRO 350 kicking about somewhere, mumble, mumble, must have a tidy up and see if I can't find it.
Took it off a lathe and replaced it with proper commercial unit.

John S.
John Stevenson

Offline picclock

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Re: DRO questions
« Reply #21 on: February 20, 2011, 01:39:30 PM »
@ John
That kinda begs the question as to why you replaced it ?

@j45on

http://www.virtualvillage.co.uk/300mm-lcd-display-module-for-caliper-vernier-gauge-new-001481-078.html

may work out OK. The one that's on there at the moment uses a 2032 battery (large coin cell) but I'm happy to change it to the regular style. Looks like an interesting place. Many thanks for the link.

All the Best

picclock
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Offline John Stevenson

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Re: DRO questions
« Reply #22 on: February 20, 2011, 02:03:06 PM »
The Chinese scale calipers ore useless on a lathe due to the precision and repeatability.

They have a published accuracy of 0.001" which in practice can be as much as 0.002", as a lathe measures and cuts a radius every measurement  is multiplied by two.

This also applies to errors.

So that best case of plus or minus one can soon add up to 4 thou on diameter.
If, like me you have to do loads of bearing diameters this is nowhere near good enough.
Another problem I had which others have also had is the numbers danching about making what you are reading pot luck.
They work for some, not everybody.

On a mill for home shop use they may well be all right but like most of the what was cheap options, the price differential between Chinese scales and  glass scales are getting closer.

Add to this, and it's not fully understood but 'some' of the latest import scales have a different protocol to the existing ones making them not compatible with the Shumatech and remote displays.
Don't take this as written in stone as it's too early to get a full picture whether it's just some or all and how you recognise the types.

John S.
John Stevenson

Offline raynerd

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Re: DRO questions
« Reply #23 on: February 20, 2011, 03:18:27 PM »
Just a word of warning - I thought I`d hit the jackpot when I found the virtual village heads at £3 a replacement but the two I purchased wouldn`t link up with the shumatech!!!! The ones I got were the £4 ones that seem to be sold out at the moment.... anyone else experienced this?

Chris

EDIT--
Just read Johns post:
Quote
Add to this, and it's not fully understood but 'some' of the latest import scales have a different protocol to the existing ones making them not compatible with the Shumatech and remote displays.
Don't take this as written in stone as it's too early to get a full picture whether it's just some or all and how you recognise the types.

Glad it isn`t just me then! I thought I hadn`t wired it correctly.

Offline kwackers

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Re: DRO questions
« Reply #24 on: February 20, 2011, 05:07:18 PM »
Probably worth addressing a couple of the points in Johns post above.

Protocols: The newer 550 (or the DPU upgrade for the 350) can handle most (if not all) the current protocols used.

Jitter: There were whole threads about different ways to fix this, however again the 550 (or DPU) don't suffer from this due to changes in ground layout. Because of this repeatability is higher - although accuracy remains a factor of the scale in question.

The 550 (or 350) doesn't preclude the option to run with glass scales, the beauty of them is you can combine where necessary both types.

Finally, cheap glass scales have a lot of the accuracy issues that the capacitive (Chinese) scales have. If you find cheap scales somewhere probably worth checking to see if they come with a calibration chart which will show how accurate they are for any point on the scale, I believe some of the very cheap ones don't come with any calibration - however they should still have excellent repeatability.
Worth pointing out that capacitive scales tend to be inaccurate due to price rather than some inherent problem with the technology.

However, if like me you tend to make stuff that simply 'fits' something else then absolute accuracy is less important than repeatability. I tend to machine to within a thou or so and then work with either the other part or a micrometer.
I don't think with amateur equipment its worth getting too hung up on accuracy, unless your scale is fitted to the tool point there are a myriad of ways in which accuracy can be compromised.