Re: [CAD_CAM_EDM_DRO] Rotary to linear translation - an interesting idea.

> Now, can someone tell me how bending a ribbon around a wheel changes the
> wheel's diameter? I'm well aware of the effects of stretch/compression
> in bending, having worked in sheetmetal. Remember though, the wheel
> interfaces with the surface of the ribbon, not it's centerline.
>

Because the Length of that compressed surface will not be the same
as the Length of the centerline on the ribbon or cable.

To restate your statement:
The wheel interfaces with the surface of the ribbon, which is
compressed. Not it's centerline which is the length we are
actually trying to measure.

If the ribbon or cable only goes half way around a wheel, that
compression and expansion will be taking place as it moves
around the wheel.

You'd like to presume the error will even out, maybe, maybe not.

Maybe there will be more or less tension on the uptake side of
the wheel, and it will slip more moving one way or another.

Maybe the wheel will have microscopic "Teeth" from the machining
operation that will provide more grip one direction than the other.

Yes, we are talking micriscopic effects, BUT they could easily be
cumlative, and we ARE measuring microscopic distances.


You could analyze it to death.

I'm more of the measure it and see camp then the analyze it to
death type.

You could take a rock tied in a hankerchief and analyze it to
death calculating the expected drag and acceleration to figure
how long it will take to fall from a tower, or you can just go
drop the stinkin' thing half a dozen times and measure it.

Odds being right and effort required greatly favor the latter.

Marc