1114 and 2056's shooter wheels

[Dale]

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

[AdamHeard]

Originally Posted by Dale

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.

[MichaelBick]

Originally Posted by AdamHeard

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.

[Akash Rastogi]

Originally Posted by AdamHeard

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.

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

[AdamHeard]

Originally Posted by Akash Rastogi

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.

[themccannman]

Originally Posted by Akash Rastogi

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?

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.

[AdamHeard]

Originally Posted by themccannman

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.

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.

[themccannman]

Originally Posted by AdamHeard

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.

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

[Cory]

Originally Posted by Akash Rastogi

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?

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.

[thefro526]

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.

[Cory]

Originally Posted by thefro526

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.

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

[who716]

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.

[Adrian Clark]

Originally Posted by AdamHeard

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.

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.

[Racer26]

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?

[Holtzman]

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.

Originally Posted by Racer26

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?