Gear Making Information

[Alan Ing]

Hi all! I guess its time to brush off my old engineering books and start thinking about the 2002 competition.

Last year I had a chance to go to the Kickoff and sat in on a presentation by Mr. Joe Johnson and Mr. Michael Civaglia (Sorry if I didn't spell that right, thanks for having that second class after the Kickoff in the hotel lobby). Anyway I found their presentation the most useful with a lot of practical information about motor sizing, gear ratios and suggestions on how to use them. After the presentation, I was all set to find sources of premanufactured gears when I discovered that the 2001 rules limited gears to what you could purchase through SPI or what you could make with the approved materials list. Does anyone know if the same rules apply?

Fortunately, this gear limitation didn't hinder us too much, as we were still able to construct a fairly competitive robot, but I know that we would have had more options if we had the capability to cut our own gears.

With that in mind, I was wondering if the teams that cut their own gears could share with us how they did it and with what approved materials?

I'm assuming that it can be done with a standard Milling Machine a gear cutter, and a quality divider head. Any thoughts about that?

How about the Diametrical Pitch and Pressure Angle of the Drill Motor and Fisher Price motor pinion gear? I also understand that the gears may be metric so the Module system may be used (Is the Fisher Price motor Module .8 and the Drill Motor .7 ?)

What materials would you suggest, 1/4" plate steel and round shafts?

Do you have to Heat Treat the gears once you cut them? Can you do that with a torch?

Sorry, these questions may be elementary for some, but I am an E.E. who acts as the lead design engineer for our team.

Oh, one more question directed to the Technokats, in your dual motor assembly, how does one go about lightly welding that hex coupler to the back of the Drill Motor without destroying it (TIG, MIG?), any precautions?

Well, I guess I asked enough for my first post. Any information would be greatly appreciated.