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Unread 18-01-2011, 16:19
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Re: Minibot climb rate

Quote:
Originally Posted by JesseK View Post
If resistors & diodes were allowed, perhaps when combined with a diode this would work fine.
If you are intent on driving it down, you can switch the motors to be in series and this will at least cut the voltage in half for each motor which effectively cuts the power by 1/4 th.

But I can't imagine that the drag torque of these motors when properly geared for speed will be enough to hold the bot up the pole with no power. I don't have a number for the FTC motors but the vex 393 motors have about 1 inlb of drag torque or about 7 % of the Max torque. If the FTC are about the same % then you would only get about 21 oz in of drag per motor or a total of 42 oz in (2.6 inlb) for two motors. . The load torque for a 4 lb minibot would be 4*radius*gear_ratio which for a typical mini bot is 4*2*2 = 8 inlb. So I think the minibot should come down by its self with my assumptions.