I noticed that 1114 and 2056 used some blue shooter wheels that seemed to work really well. I just wanted to know if anybody else used them and had any idea what there were. I think they are a McMaster-Carr buy but there are so many products on that site that some things are a little hard to find if you are looking for something specific. If there is any one that can help it is much appreciated!
I believe the part number you are looking for is 2477k36 on mcmaster.
So they made custom hubs for the wheels?
McMaster 2477K36 in 60A I believe. They have a 1.25" bore in the middle.
We machined a hub to interface with 1/2" keyed shaft. The hub was just a piece of 6061 round stock turned to press fit into the wheels bore. I took a look at 1114s hubs and they knurled them to make the press fit better. We didn’t have the resources to do so but were fine through all of champs.
They are in fact 2477K36. We used them both this year and last year with some success. They also seem to have gained reasonably popularity with a number of teams by Champs. I saw 254, 973, 1717, 1678, and probably some others all using them.
Don’t spin them over 10,000rpm. Bad things happen. 5-6k rpm :]
As a couple of others have pointed out the McMaster part number for these wheels is 2477K36 and the description is: “Large-Bore Urethane Drive Roller, 60A Durometer, 4” Diameter, 0.92" W, 1-1/4" Bore ID". 2056 first used these wheels in 2012, so we decided to try them out this year. They were easy to work with and incredibly robust. They did require a custom hub, but it was a fairly simple part to machine. A drawing of the hub is attached.
Thank you SO much for the info, I definatly did not expect to get replies from both teams.
3138 used the same wheel this year and last year. They’ve worked out great for us.
Thanks for posting that information, Tyler and Karthik. I always assumed it was a custom molded wheel before.
One more thing, how much compression was typically run with these wheels on the disks?
We had to run probably 3 times as much compression with this wheel than we did with the blue banebots wheel it replaced. I don’t know what that is in absolute terms, but it was a lot.
It should be mentioned that we were running them at much higher speeds, since ours were turned down to 2-7/8" to match the BB wheels they replaced.
We ran ours with about 1/4" to 1/2" of compression. At speed, they noticeably increase in diameter as the urethane stretches (which is why you shouldn’t run them at extremely high speeds – we blew two of them open at the Sacramento Regional). However, in practice the frisbee buckled upward much more than the urethane compressed.
How much wear did you experience with these wheels? Did you ever replace them before/during an event?
What rpm would you say is the breaking point of the wheels?
Can’t speak for 254, but ours, at 60A durometer, never wore and never had to be replaced (unless they exploded).
What was the advantage of these over the Banebots wheels of the same hardness?
No exaggeration, in the context of this season they pretty much last forever. Our practice bot has shot easily over 10,000 frisbees and the wear is insignificant.
To further prove this point, our banebots wheels would shred. When we switched to the MC wheels we started getting a thin film of plastic on the wheels.
Any comment on approximate RPM it takes to break the suckers as Cory mentioned?
We didn’t blow up any Blue (60/65A ?) but we did blow up a yellow 35A at 6 kprm. This was likely do to it being softer, and it’s hub was noticeably out of round. It also ballooned a solid inch or more.
We ran the blue at 10 krpm and poked it with an aluminum shaft a few times. Also took ~ 100 shots at this rpm over the course of the season. Never failed a blue. I’m not comfortable saying it’s safe to run 10 krpm as we didn’t really give it a fair and realistic lifecycle test.
I’m very comfortable saying that with a concentric hub 6k rpm is fine indefinitely.