1114 and 2056's shooter wheels
 

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!

Re: 1114 and 2056's shooter wheels
 

I believe the part number you are looking for is 2477k36 on mcmaster.

Re: 1114 and 2056's shooter wheels
 

So they made custom hubs for the wheels?

Re: 1114 and 2056's shooter 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.

Re: 1114 and 2056's shooter wheels
 

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 :]

Re: 1114 and 2056's shooter wheels
 

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.

Edit: 2056 posted the same info above.

Re: 1114 and 2056's shooter wheels
 

Thank you SO much for the info, I definatly did not expect to get replies from both teams.

Re: 1114 and 2056's shooter wheels
 

3138 used the same wheel this year and last year. They've worked out great for us.

Re: 1114 and 2056's shooter wheels
 

Thanks for posting that information, Tyler and Karthik. I always assumed it was a custom molded wheel before.

Re: 1114 and 2056's shooter wheels
 

One more thing, how much compression was typically run with these wheels on the disks?

Re: 1114 and 2056's shooter wheels
 

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.

Re: 1114 and 2056's shooter wheels
 

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.

Re: 1114 and 2056's shooter wheels
 

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.

Re: 1114 and 2056's shooter wheels
 

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?

Re: 1114 and 2056's shooter wheels
 

Can't speak for 254, but ours, at 60A durometer, never wore and never had to be replaced (unless they exploded).

Re: 1114 and 2056's shooter wheels
 

What was the advantage of these over the Banebots wheels of the same hardness?

Re: 1114 and 2056's shooter wheels
 

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.

Re: 1114 and 2056's shooter wheels
 

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.

Re: 1114 and 2056's shooter wheels
 

Any comment on approximate RPM it takes to break the suckers as Cory mentioned?

Re: 1114 and 2056's shooter wheels
 

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.

Re: 1114 and 2056's shooter wheels
 

As T^2 already mentioned our wheels did not wear at all, instead the plastic form the frisbees actually got melted/caked onto the wheel. You'll probably run out of frisbees before you wear down these wheels. At their off-the-shelf diameter I would not recommend running them at more than ~8,500rpm for more than ~10 seconds as they will literally tear themselves apart as previously mentioned.

Re: 1114 and 2056's shooter wheels
 

I think this is largely a function of how concentric the hub is. We went a little overbaord on our hubs and they are pretty darn concentric. I saw a few teams running wheels that had the slightest amount of runout and that really was noticeable audibly.

Re: 1114 and 2056's shooter wheels
 

It probably is, what was the max rpm you were able to run yours at without breaking? We got ours up to a little under 10,000rpm for about 20sec before the wheel split. Even if your wheels are perfectly concentric I don't know if I'd recommend running it at that kind of speed, the amount that wheel stretches is a little unnerving:yikes:

Re: 1114 and 2056's shooter wheels
 

Zero wear.

At 2-7/8" we ran them up to 13,000 RPM with no problems, though our normal operating speed was around 10,500 rpm. That works out to almost 10,000 surface feet per minute. The same surface speed for the 4" wheel would be roughly 9000 RPM, though it's going to expand more and give you a higher effective surface speed.

I know 233 accidentally ran a 4" one up to 13,000 and it exploded nearly immediately.

Re: 1114 and 2056's shooter wheels
 

We've been running a pair of these wheels since Wednesday evening of the Championship in our shooter and they're probably the 'best' shooter wheel we've found thus far.

Couple of notes:

- They don't 'wear' at least for FRC purposes
- The bore on our wheels measured something like .252 - .253" and is a bit rough... Presses can be fun. (2477K36)
- Forget trying to cut/damage/mark them using a conventional method.
- The wheel will expand a bit as it spins up, we observed something around .125" gain in OD around 5k RPM.

Also, add us to the list of those who have had a wheel fail from spinning it too quickly. The Second wheel on our shooter spins somewhere around 11,000rpm at 100% (which is way outside of our normal operating speed) and during testing, we had one of the wheels start to rip itself apart. I have a picture somewhere, if I find it, I'll post it here.

Re: 1114 and 2056's shooter wheels
 

You can turn them on a lathe with a properly ground, very sharp HSS tool.

Re: 1114 and 2056's shooter wheels
 

i would love to try the mcmaster wheels, we used the banebot wheels as the wear was pretty bad, we had to keep replacing them about twice an event.

Re: 1114 and 2056's shooter wheels
 

I think we would have noticed if our wheel wasn't concentric. Our shooter ran very smoothly without much noise.

I think the reason these wheels fail is largely a function of time. When prototyping we ran a 4" 1:1 off a 550 for a few seconds and the wheel was fine.

Every we shot our wheel would expand considerably, and the stress of the repeated expansion coupled with how fast we were running the wheel was what caused it to fail. Like I said the failure is a function of time, not just speed.

I believe the urethane wheels are bound to fail at some point when run at FRC speeds. There's no magic rpm that they fail at, it's just a question of how long you want them to last. If you run them at 10,000 rpm or slower they'll probably last a season, anything faster and you're pushing your luck.

Re: 1114 and 2056's shooter wheels
 

Inquiring minds want to know:

How are 1114 and 2056 getting their hands on McMaster parts? I've tried to order from them before, and they just tell me they won't ship to anyone who isn't an existing customer in Canada.

Are they getting IFI, or some friendly american team to buy for them?

Re: 1114 and 2056's shooter wheels
 

We've had a McMaster Carr account since 2007. This must have been before their policy not to accept new Canadian customers. Their customer service is second to none. My advice would be to email them explaining your situation(being a highschool team, exposing future engineers to their company, blah, blah, blah), and ask them to open an account for you.

Either that or find a local company that already has an account and doesn't mind sliding a few parts in with their orders.

Re: 1114 and 2056's shooter wheels
 

Ah. I figured that might be the case for 1114, was unsure when the ban on new Canadian accounts started, but it seems like it was somewhere in the neighborhood of 2009 from what I can find based on Canadians complaining on online forums about it.

Re: 1114 and 2056's shooter wheels
 

Does anyone happen to have a weight on these wheels?

Re: 1114 and 2056's shooter wheels
 

They're not interested. Future engineers, we'll pay you, and others teams spend x dollars annually didn't help.

We had a friend in the US try and order some blue nitrile for us, and even then they wouldn't ship it across the border.

Re: 1114 and 2056's shooter wheels
 

I know my employer has an account. I'm sure I could convince my boss to let me piggyback some stuff on an order if 4343 needed something and couldn't get it somewhere else.

Re: 1114 and 2056's shooter wheels
 

From what I recall they got busted under the Patriot Act for selling something that has 5 million and one different uses (with only one of them being dangerous)to people in the Persian Gulf.

After that they must have decided it was easier to not deal with any new foreigners. From what I understand they are very rigid in this policy, even sometimes refusing to ship orders that look like they're headed to a border town to be brought over into Canada.

Re: 1114 and 2056's shooter wheels
 

our rookie team was able to create an account and put orders out.
we have had some of our orders denied when we set the shipping address to a mentors house, but when we ship it to the school there are no problems.

Re: 1114 and 2056's shooter wheels
 

Actually our first order was refused because we were not a long standing Canadian Customer. So I ordered and shipped to a US mail box once. Then the next fall tried again, and voila, we were a long standing Canadian customer and have had our orders delivered to the school next day ever since.

Re: 1114 and 2056's shooter wheels
 

apparently if you state that the order is going to a school address for FIRST robotics it will go through.

Re: 1114 and 2056's shooter wheels
 

So is there not a best compression to the disks? Or is it 1/2in to a 1/4in?

Re: 1114 and 2056's shooter wheels
 

You're going to have to try it and see. It's completely dependent on what the surface opposite the wheel is. There's no shortcut for testing it yourself.

Re: 1114 and 2056's shooter wheels
 

Sweet thanks for the info! I am trying to get access to my teams parts and robot.. They are both in a chemistry closet right now :p We are going to test them soon though.

Re: 1114 and 2056's shooter wheels
 

Anyone try these with a cut down version of the WCP colson hub? It looks like the OD of the hub might be a bit to small but I'm not sure.

Re: 1114 and 2056's shooter wheels
 

We haven't, but it should be super easy to make a hub. You turn down 1.375" or 1.5" stock a bit, bore, and then cutoff. Later you broach. Assuming you have a lathe and arbor press it is super easy to do.

Re: 1114 and 2056's shooter wheels
 

Rather a large assumptions for the majority of FRC teams. We'll probably be calling in a favor or two to get a few made for us before IRI.

Re: 1114 and 2056's shooter wheels
 

Ah, good to know. At the Championship, we were trying to come up with a quick fix for an encoder disk (previous wheel had a piece of retro reflective tape on the hub) and discovered that the wheels are really tough to work with.

Having made hubs for both Colsons and these Urethane Wheels, I can say that the hubs are similar, but a hub made for a colson would be too small for the urethane wheel. If you really wanted to, you could sleeve the urethane wheel with a piece of 1.25" (nominal) tubing that's somewhere around 1/32" wall and probably make something work, but at that point, it might be more prudent to just make hubs that are the correct OD.

I have a drawing somewhere of the hubs that we're running in our urethane wheels, if you need it/it'll help expedite getting them made in time for IRI, shoot me a PM.

Re: 1114 and 2056's shooter wheels
 

See this website for more details.

Re: 1114 and 2056's shooter wheels
 

We had no issue attaching a piece of adhesive backed retro reflective tape to the surface of this wheel. The main thing we needed to do was point the sensor towards the wheel at a 45 degree angle so that we wouldn't get reflection off our aluminum hub.

Re: 1114 and 2056's shooter wheels
 

That's weird, we couldn't get our retroreflective tape to stick to the urethane part(s) of the wheel at all. As we were trying to come up with a solution, we played around with a sharpie, a saw (trying to cut some of the surface to make a 'different' patch), an open flame (outside), and a few other things before finally settling on a piece of card stock with a strip of retro reflective tape. This worked well enough through the CMP, but we ended up replacing the cardboard discs with a purpose built plastic part before our first offseason.

Re: 1114 and 2056's shooter wheels
 

Wasn't a good portion of this strip on the metal hub itself?