Go to Post A good teacher always needs to be a good student - Redhead Jokes [more]
Home
Go Back   Chief Delphi > Other > FIRST Tech Challenge
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
Reply
 
Thread Tools Rate Thread Display Modes
  #1   Spotlight this post!  
Unread 19-02-2015, 12:35
ftelliott ftelliott is offline
Sunset High School Head Coach
AKA: Friedrich Elliott
FTC #8811 (RoBo Bison)
Team Role: Coach
 
Join Date: Nov 2014
Rookie Year: 2013
Location: Dallas
Posts: 6
ftelliott is an unknown quantity at this point
[FTC]: Tetrix Gear Backlash

Hi Everyone

I am looking for clever way to reduce the amount of backlash we have in a couple of our subsystems.

Starting with the motor, we have a centrally-mounted Tetrix motor and a small gear mounted on a Tetrix channel with the motor axle centered on one of the large holes. In an adjacent hole, we have an axle with another small Tetrix gear mounted on an axle hub. This axle spins two more small Tetrix gears on each side of the robot, each of which engage a large Tetrix gear attached to our lift. So its: motor with directly mounted small gear --> small gear on long transverse axle ---> two small gears each side --> large gear each side. The backlash comes from the motor's backlash, the one small-to-small gear-to-gear mesh followed by a small-to-large gear-to-gear mesh on each side.

If it was a motor whose axle was not constrained by location, we would just rotate the motor in the mount until the gears were nicely engaged. However, in our current setup, all the gears need to be spaced by the Tetrix hole pattern and they're a bit loose. Any clever way to reduce the backlash without relocating everything or eliminating some of the gears?

Thanks!
Reply With Quote
  #2   Spotlight this post!  
Unread 19-02-2015, 15:07
MattRain MattRain is offline
AZ FTC AF, FTC #2844 and FTC #8640
FRC #1492 (Team Caution)
Team Role: RoboCoach
 
Join Date: Sep 2012
Rookie Year: 2008
Location: Chandler, Arizona
Posts: 316
MattRain has a brilliant futureMattRain has a brilliant futureMattRain has a brilliant futureMattRain has a brilliant futureMattRain has a brilliant futureMattRain has a brilliant futureMattRain has a brilliant futureMattRain has a brilliant futureMattRain has a brilliant futureMattRain has a brilliant futureMattRain has a brilliant future
Re: [FTC]: Tetrix Gear Backlash

Over the years we have gone away with using any of the tetrix hole patterns partly because of this problem. It doesn't allow you to mesh the gears all the way, resulting in a lot of play. If its not to hard, try replacing that section with square stock or something and drill your own holes.
__________________

2015 FTC WORLD CHAMPIONS
www.valleyx2844.com
Twitters: Valley X & Trojan Robotics & Team Caution
(World Championship Counter: 5)
*All my posts reflect my opinion, not my teams.*
"I WANT CHEETOS!" - Bad Lip Reading 2016 <-- ME
Reply With Quote
  #3   Spotlight this post!  
Unread 19-02-2015, 17:15
TheThings5926 TheThings5926 is offline
Registered User
FTC #5926
 
Join Date: Dec 2012
Location: Minnesota
Posts: 15
TheThings5926 is an unknown quantity at this point
Re: [FTC]: Tetrix Gear Backlash

Our team didn't use any Tetrix this year because of a similar problem among other problems with the system. If you have access to a drill press or some way of drilling aluminum stock I highly recommend replacing it like MattRain said. We drilled the holes big enough to still fit the Tetrix brass bushings.
Reply With Quote
Reply


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 17:03.

The Chief Delphi Forums are sponsored by Innovation First International, Inc.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi