Calculate Error from uneven rail and reference

[John McNamara]

Hi All

Below is two images of the wire supports I made, As you can see made from scraps of mild steel rough machined to size. The dovetails (SIC) are just groves cut with a standard end mill with the parts held at 45 deg in the mill. I also machined the clamp to fit the bed of the lathe the clamps were set about 3800mm apart.

The long dovetail rail has two carriages one fixed one movable by a simple screw, that provides a simple Y axis, the slide clamps were set very tight for lateral adjustment the stack of washers on a grade 8 bolt worked fine, the wire does not run on the threads just the smooth section on the bolt For scale the large fastenings are M8. While he setup was crude it got the job done, once tightened the setup rigid and .0001" setting accuracy was easily obtained.

My objective was to get the job done fast a few hours making the jig. They are not pretty. certainly not up to the standard of a model makers work.

Stainless steel has a lower tensile strength than carbon steel.

You need the lightest weight, and that will be the the thinnest material with the highest tensile strength to resist the pull of gravity. I double checked the number on my roll of Roslau wire and it is marked #2 it measures about .008"
I remember at the time there was a finer one but it was not in stock.

The only real alternative to high carbon steel is a synthetic material like carbon fiber, Aramid etc. I have read university papers where these materials have been tried. They were more difficult to read because of uneven the surface finish on the material. They are also non conductive, one very popular method to sense the wire is by a simple electrical contact. (Actually the point where contact is lost, that guarantees you are not deflecting the wire.)

Regards
John

[magicniner]

Very impressive, how does the machine run?