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Unread 12-02-2012, 14:45
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FRC #1197 (Torbots)
Team Role: Engineer
 
Join Date: Jan 2005
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Re: Getting more range out of a 4 wheel shooter

Quote:
Originally Posted by eddie12390 View Post
It wasn't really my decision. The impression that I have gotten from why that decision was made is that we had already made a shooter with CIMs going into the CIMple box and the person building it didn't want to take the CIMple box off of the bot. I had actually suggested removing the CIMple box from the equation but it was basically said that we didn't have time for "that type of change".
"There's never enough time to do it right, but always enough time to do it over." Guess what, you have a week to do it over, because 5 weeks wasn't long enough to do it right.

The CIM-U-LATOR runs a 2.7:1 reduction; the 775 turns at 19500 rpm with no load. This gives 7222 rpm going into the CIMple box (about 2K more RPM than a CIM). The CIMple box has a 4.67:1 ratio; this means that the output is spinning at about 1500 rpm. Torque-wise, however, you went from 166.4 oz-in stall torque (motor only) up to almost 2100 oz-in (motor through two gearboxes). That's a bit more than you should ever need for a lightly-loaded shooter! (Your total reduction is about 12.61:1; that's a wee bit on the high side for something that needs to spin fast.)

Pull the CIMple box out, and your speed goes up by about a factor of 5, your stall torque goes down by the same factor, give-or-take a bit for loading and speed. That should give a much longer range, while still allowing you to load and fire easily without jamming up.
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Past teams:
2003-2007: FRC0330 BeachBots
2008: FRC1135 Shmoebotics
2012: FRC4046 Schroedinger's Dragons

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