pic: Team 1717's PenguinBot 2008

[Amir]

Originally Posted by rc_cola1323

Could anyone explain how they got that fast of a forklift built?

We used two fisher price motors inserted into banebots 64:1 transmissions. This decision was reached by performing some simple tests coupled with a motor curve analysis.

We built a simple winch set-up that used the fisherprice motors with the KOP fisherprice gearboxes. We evaluated the motor performance under load lifting different amounts of weight. We measured the current under load and compared this with the motor power curves. We then decided on a "safe zone" in which we felt comfortable operating our motors. This was between max efficiency and max power.

We then used a basic physics analysis, W=FD and P=W/t, using the predicted load of the ball and lift combined. Using this information and the data collected from our tests, we were able to determine the most effective transmission and winch diameter combination.

We actually played it safe with 64:1. We could have used 48:1 which would have made it lift even faster and still been within the limits of our "safe zone." We decided, however, to be conservative and stick with 64:1.

We ran this forklift up and down hundreds of times and played matches all the way through finals at two regionals and the championship and never had a motor problem. We bought 10 spares just in case and never had to replace a motor. The fisher price motors are really quite amazing if they are used under non-stall conditions and at the sweet spot on their power curve. Finally, our lift had a built-in ratchet that did not allow the motors to back drive.

Hope this is somewhat clear and informative

Amir