This is not entirely a 3D printing question, but closely related since I want to print parts for a prototype.
The problem : I need to create a mechanism with 2 parallel shafts, at some distance apart, rotating in the same direction, either clock- or anticlock-wise.
The distance (> 1m) makes it impractical to set a chain of gears between the shafts, so my approach is to have a third shaft at 90 degrees with bevel gears; the driving motor will attach to this third shaft.
Not being a mechanical engineer, I tried to understand a bit more about bevel gears, and found out there are straight, spiral and other types. For printing I came across a very good OpenSCAD script that creates bevel gears with angled teeth.
So here's the 1st question : for any type of bevel gear except the straight ones, does the geometry of the teeth impact on the direction of rotation ?
Since I don't want different rotation speeds on the parallel shafts, and there is no constraint of the rotation speed of the third, my plan is to create gears with identical sizes.
2nd question : Should I use larger or smaller gears ? What's the impact of the number of teeth on the gear operation for the bevel gears ?
And last, but not least, any hints, comments or suggestions on printing the gears is appreciated.
Thank you all in advance.