Thread: 9 ft/sec for an 8" wheel drive?
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Unread 15-01-2016, 13:49
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Re: 9 ft/sec for an 8" wheel drive?
Quote:
Originally Posted by SerpentEagle View Post
Well, again, JVN's calculator doesn't account for touque.

https://www.google.com/url?sa=i&rct=...52968790615117

As you can see in the motor curve, as the torque usage goes up, speed goes inversely down.

Please correct me if I'm wrong.
It's definitely possible to go faster than 9 ft/sec in an 8" wheel drive.

I think your spreadsheet has a few mistakes. First of all, your top speed shouldn't depend on your robot's weight at all, and a CIM's stall current is more than 22 amps.

You're right in saying that torque and speed are inversely related. Because your gearbox isn't perfectly efficient, travelling at constant speed requires a small amount of torque from the motor. This causes robots to travel slightly slower than their free speed.

However, there is no easy calculation to determine losses due to friction in a gearbox. You can approximate it like JVN's calculator does by multiplying by a constant.