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

Wait a minute. Not so fast. There might be something here to think about.

If the ribbon is straight and the wheel just touches it, it will rotate based
on the actual wheel diameter.

If the ribbon is wrapped around part of the wheel, that is not true any longer.
The inside of the ribbon will compress and outside will stretch to be able to
bend. Then presumably, the center line will be what stays the same.
Our wheel rotation will then be based on the old wheel diameter + half the
ribbon thickness and therefore it will rotate slower for the same movement.

That the ribbon is bent the other way across the bearings should not matter
since the average centerline of the ribbon is what counts.

Myself, I would go for a as stable and rigid mechanical setup as possible,
never mind complicating it by making it adjustable, and then use a
microprocessor to calibrate it in software.
Bertho Boman
============================
beer@... wrote:

>
> > Here's the interesting part, that I haven't been able to get my head
> > around.
> > The guy claims that by pressing the pulley farther and farther into
> > the shim stock, causing greater and greater deflections ( adjusting
> > tension as required ), the pulley diameter is effectively changed - a
> > given amount of linear travel will cause more or less rotation.