View Single Post
  #4   Spotlight this post!  
Unread 30-04-2008, 11:49
Unsung FIRST Hero
JVN JVN is offline
@JohnVNeun
AKA: John Vielkind-Neun
FRC #0148 (Robowranglers)
Team Role: Engineer
 
Join Date: May 2001
Rookie Year: 2000
Location: Greenville, Tx
Posts: 3,159
JVN has a reputation beyond reputeJVN has a reputation beyond reputeJVN has a reputation beyond reputeJVN has a reputation beyond reputeJVN has a reputation beyond reputeJVN has a reputation beyond reputeJVN has a reputation beyond reputeJVN has a reputation beyond reputeJVN has a reputation beyond reputeJVN has a reputation beyond reputeJVN has a reputation beyond repute
Re: my team needs crab/swerve pod cad files

Quote:
Originally Posted by s_forbes View Post
Great files, John! Quick question about that module: What type of bearing are you using for the large turntable? (and where does it come from?) I would have thought that a design with a single bearing like that would put enormous side loads on the bearing that it couldn't handle. Did you have any problems with it at all?
Yes there are enormous side loads on the bearing, but it handled it fine. The practice chassis deformed but the bearings are fine.

The swerve bearing is a 2" ID, 2.5" OD, 0.25" THK bearing.

It is a KAYDON bearing P/N KA020XP0. You can buy it from any KAYDON distributor. (We got ours from Motion Industries.) If you say you are a FIRST team you can get a discount.

Paul Copioli was the one who recommended it to me, as it is used commonly on the real robots he works with.

After we started production on the swerve parts, I got cold feet. I have never done something like this before, and I am a pessimist by nature. I called Paul up and asked him if this bearing would be able to survive the heavy shock loads caused by our application or if we needed to support the base of the swerve module. He just laughed at me.

These bearings held up great; they were perfect for our application.

It was important to make sure that both the inner race and outer race of the bearing are WELL captivated. You can see in our cross section how we hold the bearing in place. (See above post.)

This may not be the best way to do things, it just happens to be the way we did it.

Hope this helps!

Regards,
John
__________________
In the interest of full disclosure: I work for VEX Robotics a subsidiary of Innovation First International (IFI) Crown Supplier & Proud Supporter of FIRST
Reply With Quote