Will bevel (angled) gears be better?
 

Hi Gerald,

Has anyone given any thought to using helical rack and pinions? Supposedly less likely to skip a tooth and with better/more efficient power transmission. According to this company:

http://www.atlantadrives.com/racks.htm

they are no more expensive than normal straight racks (though I don't know, yet, what their "normal" pricing is!).

The main disadvantage is that they can be tricky to align and set up.

Brian

Brian, we are not in the habit of skipping teeth with the straight rack, so we don't need improvements in that area. The springloaded pinion will have a smoother ride on a helical rack compared to a straight one.

But a helical rack introduces side forces, or an axial force on the pinion shaft. Most stepper motors have a lot of axial freeplay (temperature dependent) which will translate to backlash with a helical gear train. The oriental motor gearboxes also don't want axial forces on their shafts.