Re: [CAD_CAM_EDM_DRO] Encoder question

Robert wrote:

> Hello Everyone,
> Am I correct in thinking 200 slot disks are not a good item to use for
>
> purposes discussed here?

Well, a 200 slot disc would be what we call a 200 cycle/rev shaft
encoder.
Reading all transitions of the quadrature signals will give 800 counts
per
rotation. With a standard 5 TPI leadscrew, that would give 4000 counts
per inch, or a resolution of .00025". This isn't too bad, but will give
some
bumpiness to very fine moves, like large arc moves.

I will note I'm using 1000 cycle/rev encoders and 5 TPI screws on my
Bridgeport conversion, giving 20000 counts/in, or .00005" resolution,
on the X and Y axes. This is pretty satisfactory for most uses, but
I can't say for sure what it would be like with 5 times lower
resolution.

It may depend entirely on what type of work you plan on doing.
For a wood router, it most likely would be fine. For a high precision
milling machine to make precision optical assemblies, it would not
work well at all.

Jon