Team 2517 Swerve Now and future.

[seanthompson]

Sweet design! What speed are you geared for? Also, how long did it take to machine the gearboxes? What was the final weight of your drive train?
I am super interested in your design as our team is planning on creating a swerve drive over the summer and into next preseason.

[Tyler2517]

For the lower wheel we are planing on making them our selves. Probably out of 6061 both sides are identical in regards to the wheel. We designed them to be ran on our tiny cnc machine one operation and then cut from the block on a table top layth. Our biggest concern is that our steering motors wont have the power to turn under static load. Most likly will be using blue nytrox treed from mcmaster carr.

We were geared for 12.5-14 fps we changed several times within the season for different reasons. For the new one we are hoping at gearing at about 14.5-15 fps with the efficiency improvements but that is still in the air.

Defense is not a problem for us in terms of pushing we will play passive defense by turning our wheels against their primary pushing force so they cant back drive out motors and have to brute force over our large surface area wheels. And if we have to give a bump we can do accelerate pretty fast to deture anything.

[Tyler2517]

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Originally Posted by seanthompson

Sweet design! What speed are you geared for? Also, how long did it take to machine the gearboxes? What was the final weight of your drive train?
I am super interested in your design as our team is planning on creating a swerve drive over the summer and into next preseason.

Me and my sister managed to turn out a swerve module and a half a week. We had very little machining experience. Our lead machinists left along with our couch left the morning of kick off. The biggest thing that hurt us is that it got super cold causing a pipe to burst in the machine shop shutting it down for 2 and a half weeks. This caused problems.

They weighed in at something like 7 pounds 8 ounces? We were not very comfortable with bushing and our machining so they were made much heavier they they needed to be. Full bearings other then one bushing.

[asid61]

Is the large bushing on the swerve module aluminum or plastic?

[Tyler2517]

On the new one or the old one? the old one was a brass/plastic on the top. On all of them we are running bearings on the bottom Right above the yoke.

[Jared]

These are really cool. It looks to me like there's a thrust bearing on the bevel gear shaft. Did you guys find it necessary to add this, or did you just add it to be safe?

[cjl2625]

Why didn't you guys try field centric control?
I can't think of any reasons not to, aside from handling gyro drift. But especially with a bit of driver practice, I find it to be pretty manageable to deal with.

Also how does the driver change the center of rotation during a match?
I recently wrote some code to change the rotation point, but I don't really know how to elegantly integrate it in the driver controls.

[Tyler2517]

We ended up not running the thrust bearing on the top of the bevel gear due to running out of time there was a lot of wear on the top swerve yoke. I would have preferred to use one.

We use a standard ps2 controller and the bumpers on each side would correspond to a corner. To change we would press down on the button and as long as you were holding down it would be using said corner as the point of rotation using the left stick to move.
We did not have the experiences to start the coding on field central drive when we started to build and program. When we did get it it was to hard for the drivers to switch to with our getting a few mess ups our code also seemed very slow as we could conserve more momentum using the robot central control.