BW Electronics DROs

[michael birdParticipant @michaelbird72946]

Hi all

The article by David Haythornthwaite regarding BW Electronics systems in the October issue No 181 of MEW I found to be very interesting and encouraging for a newbie, re the ease of fitting and the price. However, before I buy I would welcome the views of the experts and anyone who has fitted and is using the system.

[michael birdParticipant @michaelbird72946]

[John KirbyParticipant @johnkirby69915]

Hello Michael,
I have just, successfully, fitted a (second hand) BW DRO to 2 axis of my Machine Mart Mini Lathe. I had previously fitted the DRO kit available for the Mini Lathe to the cross slide and the Compound Slide. I was looking to fit a DRO, of some sort, to the Saddle when this BW kit was offered to me. It was very easy to fit the DRO to the saddle and this has proved very useful. The spare sensor, I decided, might be useful to fit to the cross slide (as well as the existing DRO that I had fitted previously). The fitting of this proved a bit more problematic because of the restricted space, but I drew up a scheme that I felt would work and now have it all functioning. The advantage of the BW DRO is that it can be set to indicate diameter on the cross slide. It now is easy to take an initial cut, measure the work with a micrometer, set up the DRO display to this value, then turn down to the wanted diameter as indicated on the BW DRO display – “Magic”! This fitting to the cross slide has proved even more useful than the saddle.
What sort of lathe have you got?
If you are still interested, I have the Cross Slide fitting drawn up – 3D – on TurboCAD and you are welcome to details.
Regards
John Kirby

[John Stevenson 1Participant @johnstevenson1]

I fitted one to the cross slide of a CVA lathe some years ago, actually it’s still fitted but I don’t use it.

Repeatability is quite good but accuracy leaves a lot to be desired on a lathe due to everything being doubled because of removing material of both sides of the job.

 

BW say they are good to 0.002″ but that, on a lathe, is 0.004″ on diameter.

 

Whilst it helps to keep an eye on things it’s best to measure and go the final position using the dials.

I fitted a DRO to my TOS lathe later on and went the glass scale route for about the same money and have never regretted it as this can be used without dials very accurately.

However glass scales may not fit easily on a smaller machine as well.

 

Personally for the day I think they were very good value but the BW units have increased in price just as the glass scale units have decreased in price and it’s now a very hard choice of price versus features versus size.

 

John S.

[mgjParticipant @mgj]

Allendale have now brought out magnetic scales which are very neat and very small. They come in 2 ranges I think. One reads to some fantastically small amount, the other to the normal .0002″ (.0004″ doubled) Which is what many of the glass scales read to, and theye come in a range of sizes.With the magnetic strips,housings and heads I beleive they really have solved the problem of fitting a quality DRO onto something Myford sized, and probably on 3 axes. What I want to find out is whether you can put one of the super ones on the x slide, and ordinaries on the others, because the super ones are a tad pricey. My economy DRO box may not take too kindly to varying ranges on different axes – so I need to ask.

 

If I am not teaching my granny – one does have to calibrate the scales, (or the output to the box to be precise) but once one has that offset sorted, one can take one mike reading an inch away form the finished diameter, and provided things are rigid, it will be spot on at the far end – to the point that I have got a bit casual about micrometer readings. Which will bite me one day, but so far it hasn’t.

Edited By mgj on 19/11/2011 22:46:36

[Clive FosterParticipant @clivefoster55965]

On a lathe cross-slide its probably best to run the pull wire round a pulley for a double run giving direct cut on diameter read-out and retaining the nominal sensor accuracy. Of course this assuming the pulley is round and runs true.

 

I have one of the MPS self contained single axis units on the quill of my Bridgeport. Tucks in nicely above the micrometer scale making a neat, effective and doesn’t get in the way of the depth stop like the “display on a stick” based solutions. Being an untrusting type I use it to set the stop rather than cutting to a dimension on a live display.

 

Clive

Edited By Clive Foster on 19/11/2011 23:09:11

[VersabossParticipant @versaboss]

Mgj, from the remark about being ‘a bit casual’ I suppose you use such a magnetic system?

Can you – or anybody – tell me if that system is (electrically and connector-wise) compatible with glass scales? I once bought a display unit for Easson glass scales (mainly because I got it for a good price), but never managed to find a good way to mount such scales on my mill. This problem would be much more manageable with these magnetic scales.

I have a BW unit on the cross-slide, but never had a problem with reading movement instead of diameter.

Greetings, Hansrudolf

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