Re: [CAD_CAM_EDM_DRO] Re: DRO encoders- Rotary or Linear?

alex wrote:

>This may be a stupid question, but why not to use a normal bicycle
>chain\sprocket combination for driving an encoder?
>Is it a backlash issue?
>
>

Sprockets and chains, unless very carefully designed have an inherent
cogging effect
that causes cyclical errors every tooth, and then the chains have
variations in pitch
from roller to roller, which varies as the chain ages, and the rollers
and pins wear.
There may be instrument-grade chains, but normal bicycle chain, besides
being heavy
enough to break an encoder, are certainly not manufactured to the
tolerances needed.

W. M. Berg has all sorts of miniature instrument-type cable-chains that
use plastic
molded over aircraft cable. These are not instrument-grade accuracy,
but might work
better than the bicycle chain. I use them in my mill, but only for
tachometer drive,
not the encoders.

Jon