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Unread 07-09-2016, 07:27 PM
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AKA: Gus Michel II
FRC #3946 (Tiger Robotics)
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Re: Winch ratchet and paw design

Quote:
Originally Posted by s_forbes View Post
I like seeing all of the winch systems that teams come up with, but they tend to be a bit overkill. Winches that have a large reduction from the motor, but also a large diameter spool have always bugged me.
While we never built it, one of our 2015 strap winch designs had a 2-3" diameter pulley that required lower gearing than if we'd made it half size. The reason? We needed just as much force at the end of the winching as at the beginning. The larger spool that required fewer wraps would have provided a better match of motor torque and speed to the load than a smaller one, and better linearity.



Back to OP -- what is the purpose of the hole to the left of the hex bore in the first render? At first, I thought it was for the secured end of the cord, but as I looked for a better location (not under the torque support area for one of the teeth), I realized that the cord should be threaded through the non-pawled side of the pulley to reduce the chance of fouling the pawl. Looking at the last image of the OP, it appears that the cord passes through the left (non-pawl) side. So what is that hole?
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