So, since we all had to use the special wheels for this years competition, and considering we are a rookie team without a stock of supplies, I have a question for y’all. What wheels should we use in the off season?
We really want to get some real wheels and see what our Swerve + Tank drive and pull off…
Any input/links is useful.
Thanks ahead of time!
If you are looking for wheels with more traction than the 2009 kit wheels, the easiest solution would be to use either the 2007 or 2008 kit wheels sold by Andy Mark. Andy Mark made the 2009 kit wheels and as so they have the same hub design as the 2007/2008 kit wheels which would allow you to easily swap them.
The 2007 kit wheels have a stickier tread but weaker spokes that had a tendency to break as compared to the 2008 kit wheels.
You can find them here at http://andymark.biz/wheels.html
That said, you’ll probably want to run some calculations to make sure that your drive system will hold up to the different coefficient of friction. You may find that swapping out sprockets or gearing is necessary or advantageous.
(And you may be able to find those kit wheels from another local team–not everyone uses them.)
Here are some wheels that would be pretty direct replacements:
IFI traction wheels (6" x 1"):
AM Plaction Wheels:
http://andymark.biz/plactionwheel.html
AM Performance Wheels:
http://andymark.biz/am-0132.html
Other AM Wheels:
http://andymark.biz/08firstwheel.html
http://andymark.biz/firstwheels.html
These all have the same 1.875" bolt circle, but the sprocket mounting and bore holes might differ, so it depends on how your wheels are driven (sprocket, direct drive, idler etc.) Make sure before you buy these that you look into things such as the diameter of the holes on the bolt circle.
Something else to keep in mind is whether or not you will be able to turn when you put on traction wheels. A simple 4 wheel robot will turn fine with rover wheels, but with 4 traction wheels it will have a lot of trouble.
I would be careful and make sure that your system is designed to handle the greater axial forces from being pushed sideways with high traction wheels.
I have seen a swerve drive or two from this year that would not survive traction wheels on carpet (the team knew this and it was designed with the surface in mind).
I agree about making sure your mounts, motor gearings, and other structural parts can stand the forces imparted onto high-traction wheels. Our team made our swerve modules completely out of 3/8" Lexan, and it held up fine on the FRP, but even then, it flexed quite a bit (actually did this neat little thing that helped that we didn’t expect where the wheels jumped forward while stopping, acting as an ABS). Any structural stability that was iffy when it was on FRP with the slick wheels will be magnified a hundred times.
But as for wheels, I would agree with the 2008 kit wheels. If seen less pictures of pieces of them than the 2007’s, and we haven’t had any issues with them while putting them through crazy extreme shooter tests (i.e. direct driving them from a CIM, and launching a rubber ball off of them). They’re also the same dimensions as the rover wheels, and will be relatively easy to swap out, requiring few to no modifications.