rack&pinion

Hi Doug,

Beribu-ribu terima kasih.

<prototype@c...>:"The backlash can be eliminated by preloading paired
gears, similar to preloaded ballnuts."

Sounds like something even a pseudo-engineer might be able to handle.
Have problem even thinking of how to make that "hambuger" nut, but
paired gears I can visualize. But should the spring pull the gear
together of apart, or either?

"Any redeeming factors? (like higher speed, easier > construction,
lower cost?)"

"Yes to all three. Ballscrews are limited by critical frequencies
that decrease as length increases. Even with a rotating nut
configuration the screw can resonate like a guitar string. A rack
can be of any length because it is continuously supported."

And we can make the supporting structure as solid as the Rock of
Gibralta if we so wish? (and without incurring extra shipping cost?
That sounds interesting to me!!!)

"I saw a router table recently that had the rack ground into the back
of the linear rail. The gear straddled the rail between the
carriages inside the gantry. I can send you a picture if you are
interested."

I am interested. Group files, attachment, snail mail?

Peter