rethinking gear teeth
The prototype mechanism has been reinstalled using the new framing plates made on an NC milling machine, and there is clearly an improvement. The gears move more smoothly and, unlike before, perform the same on top as on bottom, thanks to the now precise and vertical axle positioning. But the crippling backlash problem remains, despite the fact that the center-to-center spacing is now nominal for the gear diameters, not expanded. The problem, I've concluded, is in the gear tooth design. I've been naively using the Solidworks "Toolkbox" to design what I expected to be gears with standard 20-degree pressure angle involute teeth. Now I discover this disclaimer in the fine print of their documentation: "Toolbox gears are representations for machine design purposes. They are not true involute gears that you can use for manufacturing." Nice . What's more, there doesn't seem to be a backlash adjustment in their complicated set of equations, which are anyw