Gear Boxes

[Keithicus]

We're gearing the chippy and drill together for our drive, taking the output from the chippy gear, passing it through a larger gear to drive another gear on the drill drive shaft. All gears will be brass. Problem is we've never worked with gears before and I'm not sure how the basics work. Are the gears supposed to turn on a fixed shaft or do you attatch them to a rotating shaft and support that shaft with bearings? If they do slip on a fixed shaft (this would be ideal), what kind of fit do you design for? Do you have to worry about wear? What about thermal expansion? Will the gears bind on the shaft after spinning for a while and getting hot?

Any help would be greatly appreciated.

Keith Sevcik
#920

On a side note, what happens when you burn up a motor? Do the windings actually melt or short or something? Or is it that the magnets are demagnetized from the excessive heat? Do you always have to replace the motor or is it somewhat functional?