View Single Post
  #3   Spotlight this post!  
Unread 19-04-2013, 14:22
Nuttyman54's Avatar
Nuttyman54 Nuttyman54 is offline
Mentor, Tactician
AKA: Evan "Numbers" Morrison
FRC #5803 (Apex Robotics) and FRC #0971 (Spartan Robotics)
Team Role: Mentor
 
Join Date: Jan 2005
Rookie Year: 2005
Location: Seattle, WA/Mountain View, CA
Posts: 2,134
Nuttyman54 has a reputation beyond reputeNuttyman54 has a reputation beyond reputeNuttyman54 has a reputation beyond reputeNuttyman54 has a reputation beyond reputeNuttyman54 has a reputation beyond reputeNuttyman54 has a reputation beyond reputeNuttyman54 has a reputation beyond reputeNuttyman54 has a reputation beyond reputeNuttyman54 has a reputation beyond reputeNuttyman54 has a reputation beyond reputeNuttyman54 has a reputation beyond repute
Send a message via AIM to Nuttyman54
Re: White Paper Discuss: Team 33 Four Speed Transmission

Quote:
Originally Posted by fb39ca4 View Post
Anyone tried replacing the pneumatic pistons with a more powerful motor and a lead screw?
I would not recommend this. Due to the "crash" style of shifting rather than the dog-gear style used in AM supershifters and most FRC shifting transmissions, there's a high chance that the gears do not immediately engage. We noticed this when we built them in 2006. The pneumatic shifting style is well suited to this application, since it will apply a constant force, so it will continue to try to shift until the gears mesh right. A lead screw or other motor driven application has a much higher chance of breaking something, since you will either stall the shifting motor or continue to increase the force until something bends or breaks.

A NOTE TO EVERYONE:

This transmission was designed in 2004 for the drill motors that were given in the kits. These motors had a MUCH lower free speed rpm than CIM motors. 971 attempted to use CIMs with this transmission in 2006 and did not have good results. The transmission really is not designed to work at those loads and speeds, and required several extra stages of gearing before and after to bring the speeds down to what is reasonable for FRC drivetrains. It's a good transmission, but the design as-is is not really suitable for drivetrains with current FRC motors.
__________________
Reply With Quote