Quote:
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Originally Posted by AdamL118
Our gearing is 3:1 using the two drill motors tied to two wheels apiece set in low speed.
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Short story:
At 100 lbs with those wheels, you'll need to be a little slower than that if you don't want to trip your breakers on the drill motors in pushing matches...
Long story:
Drill in Low Speed:
Free Speed: 450
Stall Torque: 320 in-lbs
Stall Current: 127 Amps
Breaker Current: 40 Amps
Torque at stall current: (40 / 127) (320 in-lbs) = 103.3 in lbs
100 lbs / 4 wheels = 25 lbs / wheel
25 lbs * 1.2 COF = 30 lbs
12.5 in diameter wheel = 6.25" radius
30 * 6.25 = 187.5 in-lbs * 2 wheels / motor = 375 in lbs of torque needed.
Minumum Ratio Needed: 375 in-lbs / 103.3 in lbs = 3.63
The ratio of 4:1 that FIRST gives you in the kit is a good choice, even though you have less weight. Try running your robot against a wall on carpet- if the circuit breakers trip, you should considering reducing the gear ratio in your drive train.
I hope this helps!
Good luck everyone.
Matt