poor man's DRO

[Arthur.Marks]

is it called a compound slide because it can do compound angles? Just out of curiosity.

No. A compound angle would be in two different planes.

[aolney]

Just tonight I repaired a digital scale LCD with the rubber contact block. One of the digits was fading so much I could not read it. Took it apart, cleaned the circuit board contacts with an eraser. I believe the glass has a transparent circuit on it and the rubber block is layered with conductive/non conductive rubber. In my case I had to sand the bezel down a little to increase the contact force, but in the end was successful. (Of course I broke a teeny wire and had to solder it) I have repaired a couple of multimeters, a calculator, and a clock in the past.

Andy Olney

[Barrington]

From : http://www.lathes.co.uk/latheparts/

COMPOUND SLIDE REST consisting of the CROSS SLIDE and TOP SLIDE
Sitting on top of the "Saddle" is the "Cross Slide" - that, as its name implies, moves across the bed - and on top of that there is often a "Top Slide" or "Tool Slide" that is invariably arranged so that it can be swivelled and locked into a new position.
Very early lathes had a simple T-shaped piece of metal against which the turner "rested" his tool (all turning being done by hand) but when it became possible to move this "Rest" across the bed by a screw feed it became known, appropriately enough, as a "Slide-rest". The earliest known example of a "Slide-rest" is illustrated in Mittelalterliche Hausbuch, a German publication of about 1480.
After the "Top Slide" became a more common fitting the term "Slide-rest" was not so frequently used - and the different functions of the two slides led to their specific names being more widely adopted.
When two slides are provided (or sometimes, on watchmaker's lathes, three) the complete assembly is known as the "Compound" or "Compound Slide" or even "Compound Slide-rest". Some makers have been known to label the "Top Slide" as the "Compound Rest" or even the "Compound Slide" - but as "to compound" means the 'joining of two or more' - not 'one' - this use of the term in incorrect. The top and cross slide together should be referred to as "the compound".

Cheers

.

[mattthemuppet]

No. A compound angle would be in two different planes.

hmm, maths never was a strong point of mine

Just tonight I repaired a digital scale LCD with the rubber contact block. One of the digits was fading so much I could not read it. Took it apart, cleaned the circuit board contacts with an eraser. I believe the glass has a transparent circuit on it and the rubber block is layered with conductive/non conductive rubber. In my case I had to sand the bezel down a little to increase the contact force, but in the end was successful. (Of course I broke a teeny wire and had to solder it) I have repaired a couple of multimeters, a calculator, and a clock in the past.

Andy Olney

I'm guessing the same - that rubber must be conductive in one direction but not another. Impressively simple, that's for sure and helps to explain why these things are so cheap.

From : http://www.lathes.co.uk/latheparts/



Cheers

.

I think I'll just call it the bit on top and the bit underneath the bit on top, seems simpler!

[MrSleepy]

I'm guessing the same - that rubber must be conductive in one direction but not another.

Its commonly reffered to as Zebra strip.... very common in LCD modules etc

https://en.wikipedia.org/wiki/Elastomeric_connector

Rob

[mattthemuppet]

cool, thanks Rob, I never knew that

[Rosco-P]

What made you chose a modified tread gage instead of mounting a cheap 6" digital caliper? Doesn't the 50mm or roughly 2" travel limit its usefulness?

[mattthemuppet]

cheapness and space constraints mostly, although I'll see how I get on with this one over time. Digital calipers aren't much more from HF - $10-15 or so. To be honest, most of the work I can conceive of doing on this (housings for bike lights) will roughly fit within that envelope, so I don't think it will be too limiting. Another thing that's interesting is that the refresh rate (count rate?) on the tire gauges is alot faster than the digital caliper I have, which has been commented on before, so that's something else to consider.

Also, I need to chase down the cause of 0.5mm or so runout at 12in from the chuck before it'll even be worth working on longer items.

[mattthemuppet]

Finally I can boast that I have a 3-axis DRO on my lathe! Very quietly and mostly just to my wife, but still..

Ran into a situation where I need to drill to a precise depth, so figured that it was time to add my other tire gauge to the tail stock. Usual combination of scrap metal, random screws and magnets, but it works well.

Base with shaped bits of steel to match the diameter of the tail stock housing:


Bracket to bolt to the quill, inspired by Daryl Bane's beautiful Monarch (?) tail stock DTI holder. This one isn't quite as pretty, but it's the best I could do with a band saw and a dremel. I meant to polish it but I was starting to loose feeling in my fingers by that point (-15C in the garage), so another day perhaps:


Quill retracted:


And extended:


The quill goes out a few more mm than that but the gauge starts having a fit. If I ever need to drill deeper than 38mm I can always figure out a work around. Now I can finish making a heatsink pill for my daughter's flashlight.

(Insert smilies where appropriate, I couldn't use them due to the 4 "image" limit)