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Unread 14-05-2015, 22:21
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Shray Mittal Shray Mittal is offline
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FRC #1477 (Texas Torque)
Team Role: Leadership
 
Join Date: Mar 2015
Rookie Year: 2013
Location: The Woodlands
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Re: pic: Manually machinable one-speed gearbox

This season, 1477 used a Texas Tube style chassis. On a 4WD with all omni wheels, we used VexPro 16t #25 sprockets. We had tensioners on both our practice bot and our competition bot, and never used them on either robot. We had no issues with the 16t sprockets, and our chain runs were more than 200 links long. Game permitting, we will likely be running a Texas Tube style drive chassis again. Our experience with #25 chain in 2x1 tube has been outstanding thus far.

Quote:
Originally Posted by Dan Petrovic View Post
Alright, that's good to know! Now, since this is an awesome thread and I'm learning a lot from it, I'm going to ask another question.

Has anyone every thought about using timing belts instead of chain? Fitting it into a 2x1 box probably wouldn't be possible, but what about a 2x2 box. I'd imagine it would be even more of a "set it and forget it" scenario because a timing belt would be less likely to break than a chain.
This is something I've been thinking about a lot lately. If using 1/16th wall 2x1 tube, it is theoretically possible to run 24t pulleys and 9mm belts from VexPro inside the 2x1. This could result in an extremely lightweight and efficient drive, at the cost of some structural integrity in the drive chassis. In my experience, #25 chain is less likely to break than 9mm timing belts, but is heavier and less efficient, assuming both the belt/pulley and chain/sprocket are assembled correctly.

http://www.chiefdelphi.com/forums/sh...ad.php?t=94701

Here is a picture of 2791 running timing belts inside tube extrusion.
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