how to design sprockets

[team222badbrad]

This is what we did on our CNC this year.

We choose the chain size.
Measured the chain spacings and such
Calculated how many teeth we wanted on the sprockets.
Got some plate aluminum.
We then figured out how far the teeth/holes needed to be apart. Calculus....
Made a G code program.
Once we got the code ready we took a drill bit slightly bigger than the chain "hooks" or whatever you call them. The machine then drilled a series of spaced holes all the way around the plate of aluminum. We then placed a mill bit in the machine and machined half of the holes away.

Here are some pics of our arm's gears:

http://www.tigertrons.com/Pictures/2...n/100_0596.JPG
http://www.tigertrons.com/Pictures/2...n/100_0710.JPG
http://www.tigertrons.com/Pictures/2...n/100_0716.JPG

These worked great for us. We also made some 50 tooth sprockets for #35 chain in our drive train

[SpaceOsc]

Originally Posted by team222badbrad

This is what we did on our CNC this year.

We choose the chain size.
Measured the chain spacings and such
Calculated how many teeth we wanted on the sprockets.
Got some plate aluminum.
We then figured out how far the teeth/holes needed to be apart. Calculus....
Made a G code program.
Once we got the code ready we took a drill bit slightly bigger than the chain "hooks" or whatever you call them. The machine then drilled a series of spaced holes all the way around the plate of aluminum. We then placed a mill bit in the machine and machined half of the holes away.

Here are some pics of our arm's gears:

http://www.tigertrons.com/Pictures/2...n/100_0596.JPG
http://www.tigertrons.com/Pictures/2...n/100_0710.JPG
http://www.tigertrons.com/Pictures/2...n/100_0716.JPG

These worked great for us. We also made some 50 tooth sprockets for #35 chain in our drive train

how well did they do with the chain? did it slip any? was there a harsh destruction of metal noise? and how much did it weight?

[team222badbrad]

They did great with chain. No slipping or anything. We did have a little side wear on the drivetrain due to misaligned sprockets/chain. We have been through 10 competitions with these sprockets and they are still working.

I do not have an exact weight, but I think they weighed half as much as the steel sprockets!

You do not need any fancy programing to make a sprocket work.
Just a simple program, CNC mill, mill bit, and a drill bit!