DRO for Dore Westbury milling machine

I'm considering fitting a DRO to my Dore Westbury milling machine. There is not much space for the scales on this small mill, and there are many options on DROs. I would therefore be very interested to hear from anyone who has experience of installing a DRO on a DW.

Hello Mike,

​I fitted a 2 axis Newall Microsyn 10 system with a Topaz Mill readout, equipped with the PCD function. On the quill I have fitted a simple one axis scale from Machine DRO

It was not cheap but the installation is neat and out of the way and takes up so little of the space available. The table travel scale is 300 mm, the cross slide 175 mm. The system has been operational since early 2004

I would happily post some pictures to share but Microsoft Edge appears to be incompatible with the software used on the forum and will not allow me to post or access my album material. If you will PM me with your email address I can send the information directly to you that way

I have been really pleased with the installation. It might be OTT for a small mill like the DW but I worked hard to buy it and have not regretted it.

Regards Brian

Edited By Brian Wood on 24/08/2016 10:21:32

Thanks Brian. PM sent.

Depending on how DIY you want to go Renishaw might be an option.

**LINK**

I think that the tablet based display and associated hardware is compatible with them.

I don't have a link for that but it can be found on the web.

I have also seen a site that sells the parts. That seems to be this one now

http://www.rls.si/

John

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Edited By Ajohnw on 24/08/2016 11:42:03

Hi John,
Is this the tablet based DRO the one you are thinking about ?

Les.

Yes. That's the one.

Last time it was mentioned I think some erroneous comments were posted about it.

John

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John,

It would be a great help, to others that are interested, if you could be a little more specific.

MichaelG.

From memory there was some comment that it used ascii. From what I can gather it uses the signals that many dro sensors put out and can even cope with pure quadrature outputs which are just pulse trains, 2 in antiphase so that direction can be sensed. It may well be able to cope with ascii outputs from sensors as well as I believe some do that.

What isn't clear when I look at the site is what does what. For instance it states that a board can be easily converted to use quadrature but from what I can see no signs of how. It shouldn't be difficult to handle this in a micro because it's just a case of counting pulses and noting which one changes first so that direction can be detected. As for instance this is how car steering angles are detected. Linear motion is no different.

Being fair to the man who has done it supporting something like this can be pretty onerous for a one man band and the mixed signal board seems to be pretty new.

The unit that has to be built or bought may well use ascii to transmit data to the tablet via bluetooth but that's not really relevant because if some one dug deeply into a one piece commercial unit it might do the same to communicate with the display. All most certainly if it used a touch screen and probably in other cases as well. I have hand cranked simple displays in the past but there comes a point where it's easier to tell a display unit to do it rather than set dots or segments etc.

Bluetooth may be a weakness, noise immunity, but it seems some have converted to serial, possibly even usb. Some are using USB cable for sensor leads as they are shielded and also the connectors at times.

John

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John,

Please correct me if I am wrong, but; I think the gist of it is:

• The 'scale' puts out data in whatever format is native to it.
• The 'converter' reads this; does its magic; and outputs ASCII
• ... The ASCII data can [optionally] be transmitted to the Android device by BlueTooth or by USB cable.
• The App simply allows the Android device to display the ASCII data stream.

Sounds simple [if you're clever enough to do the magic] !!

MichaelG.

Hi Michael,
That is more or less correct. The converter does does not do much magic. All it does is convert the various data formats from the scale to ASCII strings something like this x1234;y5678;z3456 These are the raw readings from the scale without the decimal point. There can be a minus sign between the axis letter (x,y,z) and the number. The readings from the scales do not have to be an any particular sequence so you could have 3 x readings, 2 z reading then a y reading. The software on the tablet does the magic bit. It sets the reading from the scale that you want to be the zero reference and displays the readings with reference to the set zeros. I wrote a converter program as an exercise in learning to program Atmel chips that runs on an ATtiny4313. It was not too difficult. There is some information about it on my website I have not put the source code on the website as it is very untidy but if anyone is interested I will put it on the website.

Les.

Thanks for that, Les

MichaelG.

I wasn't too specific about what the converter puts out to the tablet because he could use a number of formats. It could turn out for instance that BCD (use google) would be more efficient than ascii. If I did it and wanted to maximise the data rate the converters could output I might use that as it would probably be easier to handle at the tablet end than binary as converting that to decimal is a complete and utter pain. Simple code but given big numbers it takes a long time to run. Most uP's will handle BCD conversions well. At least the ones I have done work on.

It doesn't matter much really. The main aspect is update rates and I think I have seen comment of 10 per sec on 4 scales which is fine for a DRO.

One change he has made is to switch internally to metric. From what I have read 5um scales should be fine. 1um may not be but frankly if some on pressed many milling machines with their hands the reading could change by more than that. Also looking at various scales 5um seems to be at the higher end of realistic.

If some one is going in this direct they will have to check that the scales they want to use are compatible. There may be a need to ask about scale length / resolution on bigger machines. I doubt it but it might be worth asking.

He doesn't give any info on using USB rather than bluetooth. I get the impression that people who have done this have grafted some small board or the other onto the main board in place of the bluetooth one.

John

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Do you have any indication of pricing for the RLS modules? They look most interesting!

The website does not have prices and it seems they quote only when one makes an enquiry

Because of their small size I would contemplate incorporating one and its scale 'inside' the lathe topslide.

Ian P

Like Ian, I found the RLS scales very interesting, but couldn't find prices or a stockist.

Any further info appreciated.

Mike

Les,

If you have the time; could you please clarify something for me?

The posts dated 04-Jan-2015, on this page concern the possibility of using a computer mouse with Yuriy's DRO.

http://www.yuriystoys.com/2013/10/mixed-scale-dro-controller-project.html

He seems rather circumspect about this; but I don't understand why ... I thought most mice used simple quadrature encoders.

Thanks

MichaelG.

I just used the 2nd link I posted and clicked on linear and then on one of there models and details in the lower right hand of the page have to be filled in and out pops a price and delivery time.

This is the incremental scale page. There is another for absolute

**LINK**

I'll leave clarification to Les.

John

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John,

Yuriy commented [20-Dec-2013] on this thread

http://www.model-engineer.co.uk/forums/postings.asp?th=57456&p=5

MichaelG.

John,

There really isn't that much to it. If you're using Arduino, USB should just work with most boards. FTDI-based boards work fairly well. The newer ones "often work" (the driver TouchDRO uses in theory supports all Arduino version and more, but it's been more reliable with FTDI).

That said, there is no reason to use USB and all sorts of reasons to not use it. BlueTooth is much more reliable in a workshop environment. Unless you have a tablet that has USB but no BlueTooth, I would skip USB and stick with wireless.

Regards

Yuriy

Edited By Yuriy Krushelnytskiy on 26/08/2016 03:05:15

Thanks Yurly. I'd use bluetooth. I just mentioned that there may be interference problems from say a poorly wired inverter on the machine but at circa 2.4ghz I would have thought even that would be unlikely. The leads to the sensors could be shielded which should help at that end. Also picking scales that have fairly low drive impedances which I suspect many will have.

My biggest problem is that my son bought me a rather expensive iPad when everything I want to do with one needs Android. Probably all down to me. Setting up Linux machines for him when he was young which sent him to windows when he was older and then to Apple in disgust so maybe Linux did do him some good.

John

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If that's your biggest problem, John, you must live a very contented life.

But I could help with that if you like:

A straight swap: Your "rather expensive iPad" for my little-used Tesco Hudl

MichaelG.