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Unread 19-11-2015, 10:35
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FRC #0228 (GUS Robotics); FRC #2170 (Titanium Tomahawks)
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Re: Possible to extend output shaft on WCP Gearbox?

Quote:
Originally Posted by Infinity2718 View Post
Define pushing it, what does that correlate to? When does it become an acceptable FRC design and the requirements it is held to?
9mm wide belts with 24t pulleys are the setup I've had the least experience with, but in a 6WD WCD with 4" wheels, there were issues with ratcheting, and I believe belt failure was inevitable at some point. I have heard of several other teams failing belts in this configuration.

Quote:
How do you quantify a 24t pulley 15mm setup: What size wheels? What power input from the gearbox? That can be very helpful information to say we loaded our belts to X pounds and didn't see a a failure.
In 2012, my old team ran a 4WD with 6" wheels, neither wheel direct driven, using a pair of 15mm belts and 27T pulleys. All good.

In 2013, we ran 6" wheels on a 4WD with a 4 CIM drivetrain, single speed, probably a 10:1 gear ratio or so. 15mm wide / 24T pulleys. Majority of the weight was on the direct driven wheel, so maybe not a perfect case study.

In 2014, we ran 4" wheels on a 6WD with a 6 CIM drivetrain, maybe a 7.5:1 gear ratio? (around 12 FPS). This robot had the most run time of any of our robots, with at least 100 hours put in to practicing with both a competition and a practice robot, and obviously that game had plenty of pushing defense, so in a way this was the hardest test of this belt setup yet. Never ratcheted, never failed, no issues at all.
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