Re: [CAD_CAM_EDM_DRO] Re: Rotary to linear translation AHHA! (plus an idea for backlash free gearing)
Posted by
Bertho Boman
on 2000-04-12 14:58:45 UTC
Jon,
We are getting closer to a good design.
I would not grove the sensor wheel. The accuracy would be better if it is flat
and then we basically would not care about wear of the rod since it would not
effect the effective wheel diameter.
Bertho
============================
Jon Elson wrote:
----- < snip
I am imagining wheels with semi-circular grooves in the edge, so that the shaft
wedges into the groove a bit, drastically improving the friction. I think you have
to apply the wheels to the rod with a substantial amount of force to avoid
slippage, even with very low friction bearings on the wheels. It might be
possible, especially in home shop use, to recalibrate the thing yearly or so with
gauge blocks. If most of the wear is on the wheels, it should stay accurate. If the
wear is on the rod, too, then the most used area will show more error, and it
will get non-linear.
The more worn-down rod will ride lower in the groove on the wheel, thereby
reducing the effective diameter of the wheel.
Jon
We are getting closer to a good design.
I would not grove the sensor wheel. The accuracy would be better if it is flat
and then we basically would not care about wear of the rod since it would not
effect the effective wheel diameter.
Bertho
============================
Jon Elson wrote:
----- < snip
I am imagining wheels with semi-circular grooves in the edge, so that the shaft
wedges into the groove a bit, drastically improving the friction. I think you have
to apply the wheels to the rod with a substantial amount of force to avoid
slippage, even with very low friction bearings on the wheels. It might be
possible, especially in home shop use, to recalibrate the thing yearly or so with
gauge blocks. If most of the wear is on the wheels, it should stay accurate. If the
wear is on the rod, too, then the most used area will show more error, and it
will get non-linear.
The more worn-down rod will ride lower in the groove on the wheel, thereby
reducing the effective diameter of the wheel.
Jon