While searching for some useful gears and motors inside a buggered CD drive, I noticed a few things of note to RepRap. First off, they're using a rack & pinion to move the head on rails that look pretty similar to what we've got, just smaller. The rack and it's driving motor are anti-backlashed as you can see from this photo:
The anti-backlash is the springy thing inside the big gear, for those going "huh?" The gear wheel is split, and the two halves propelled in opposite directions. This pinches the gear on the neighbouring shaft, and cuts out any slackness in the movement. A similar trick is done with the rack.
They've also only used the inner quarter contact surface of their rails, which we might try to reduce friction further.
Nice. I suppose the same thing could be done with any sort of drive mechanism. Two nuts on a threaded rod, tightened against each other with a spring, for example.
ReplyDeleteYes, that's used on a few PCB router designs but I've never seen it applied to a rack & pinion drive before. It might make the replacement of the belt drive by a rack & pinion drive practical.
ReplyDeleteVik :v)