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Unread 08-11-2012, 14:17
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Re: Different Swerve Drives

Quote:
Originally Posted by CalTran View Post
Update 11.8.12

After evaluation, the team has decided to do coaxial rather than distributed. With deliberation between our programmers and me, it was decided that working with an extended travel potentiometer is much simpler for them to do rather than working with an encoder. (Coding will most likely be done in C++, for those wondering.) Our decision is thus because we believe it will be easier in the future to switch to an encoder from potentiometer once we decided we would like more than one rotation. However, some more deliberation will be had once we can get in touch with some of our mentors from Rockwell Automation.

Also, at Jeffy's advice, I went over to FRC Designs and have dissected the Emperor Swerve corner module.
One of the things I am wondering about after looking at this design is how to design for the rotation. From what I can see in the CAD file, the wheel module is set inside a steering bearing and this is what allows for the wheel to rotate. Correct?

As well, we believe that the frame of our testing bed will be 80/20 extrusion, with the modules designed to slide on and off of the frame. As well as testing Swerve Drive on the platform, we will also look into a well-designed 6/8 wheel drive that could be slid on to the platform, so as to consolidate pricing of off season prototyping.

As a last point of note, when teams do fabricate the modules, how many are created? Four would be the minimum* (No spares), and I suppose the cap would be where you want to stop spending money on creating modules. Are two extra modules a happy medium to stop at? That would mean that we would need to fabricate six total modules.
*Note, Bomb Squad’s three wheel swerve is excluded from this analysis.

*Edit: http://www.chiefdelphi.com/forums/sh...Emperor+Swerve has shed some light on the various mountings and bearings necessary for rotation.
Keep in mind that the link you posted is a thoroughly different design in regards to bearing setups.

I like to think that our steering bearing setup, and what 1717 did, are about as simple as you can get. It's just two radial bearings spaced apart to react torque and radial loads, and then a large thrust bearing to react the robot weight.