pic: IFI-WHEEL v2

[InnovationFirst]

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[Aren_Hill]

Could we get some specs? how light how much What sizes? if you have 4"d by 2"wide that'd be amazing

[techtiger1]

I agree with the post above me specs would be nice. John and the IFI crew nice job it is definitely a much more robust, improved design. Getting ready for 07 already I see. Well, keep it up I look forward to seeing them in real life.

-Drew Dizzle

[Chuck Glick]

this is a very good thing for us, we were thinking about using the IFI wheels next year, but i saw many teams hammering them back into shape, but these wheels look much stronger and now i think we will use them... just hope the price is about the same.

[Allison]

This past year at the Cleveland regional there were issues with the IFI wheels passing inspections. Mainly the inspectors were worries about once the tread wore down that the metal on the sides and the rivets that were used to attach the tread. Will this still be an issue with this design? And if so, are you working with FIRST to assure that this years wheels will not have the same issue?

[Richard Wallace]

Originally Posted by Allison

...the inspectors were worries about once the tread wore down that the metal on the sides and the rivets that were used to attach the tread...

... might damage the carpet.

We had the same concern about a couple of robots at St. Louis also. I don't see this as a problem with the IFI wheels per se, even with worn treads. However, some teams didn't do a good job of keeping treads attached to the wheels. In all cases where an inspector noted this as a possible violation, or where a referee saw tread come off during a match, the team was able to find replacement tread material and improve its attachment. As an inspector I think the IFI wheels are fine; just be sure you put the tread on to stay. Maybe IFI could provide some additional guidance on attachment methods that are known to work well?

As a team mentor, I'd use the IFI wheels on our robot. They're light, they're strong, they work.

[Alan Ing]

In the past we have made our own wheels, but last year due to a shortage of help in our machine shop, we opted to buy the 6" IFI wheels. Without them, we would have had a lot of trouble finishing our machine and making weight.

Having said that, we did have some problems with the wheels. The biggest problem was that the three parts of the wheel that the tread gets attached to were prone to getting bent and indented on our wheels. This made the tread loose and of course the wheel looked funny because it no longer was round. Please keep in mind that our wheels were fairly protected by the bumpers and the chasis, but yet they were getting hit hard enough on the treads by the ramp and other machines to cause the three rim sections to bend and collapse in the middle (the side plates were fine).

The other problem we had was with the PEM nuts and philips head screws. Several times we had to deconstruct the wheel and bend the three rim plates back (not that easy during competition). Some of the PEM nuts came out and just spun making it difficult to disassemble (We used self locking philips head screws the ones that have plastic on the threads) instead of using loctite which became a real problem when the PEM nuts broke loose. In hindsight I would not recommend using self locking screws with PEM nuts.

It looks like the new design addresses the problems we had. The extra tangs in the center of the rim sections should give the rim sections support in the center which is where our rims bent inward and the use of Socket Head Cap Screws are much better than Philips screws. Overall looks like a much better design.

Now if only there was a better way to attach the tread

[Kevin Sevcik]

The only real problem we had with the wheels was the nuts coming loose, but it was a huge problem. They'd come loose during a match and disappear and we'd be left with a half-together wheel. We had 2 complete spares but we still ended up using some plain nuts when we finally ran out of parts with nuts still on them.

[Lil' Lavery]

116 opted to try out the IFI wheels last year as well. We used 2x 8"x1" in the front and 2x 8"x2" in the rear. We too had some problems with the nuts coming loose and even falling out (even with loc-tite). Even with the wheels protected by the frame and bumpers, they took some warpage along the 3 outer plates (hopefully this new design will fix that). Finally, during QF 2-2 at Peachtree we had a tread come loose. One of the rivets holding the end of it on actually sheared in half. Due to being unable to remove the half still attached to the wheel, and not having the foresight to bring out a spare from the pit (and our design probably not giving us the time to switch out the wheel), we were forced to wire tie the tread back to our wheel for QF 2-3 (which sadly, because of an error on my part, the drive motors were not plugged in, and we lost).

[Arefin Bari]

Team 1345 used 2 IFI wheels last year (8x2) and 4 kop wheels. We didn't have any real problem, I must say that the students put it together very nicely. However we were using the kop transmission and not Andy Mark. Even though we were in some matches that were brutal (against 61, wow what a match). matches, I don't think enough torque was applied to the IFI wheels in our configuration to cause any problem. I am planning on using IFI wheels again (after seeing the improved one) and also planning on using Andy Mark transmission. Thank you IFI for providing us with these wheels.

[Peter Matteson]

For those of you who had trouble with keeping tread attached we had a solution to this. Use rivets with oversized heads. I believe McMaster calls them big head rivets. Once we swtched we never popped a tread again, and to be honest the one we popped was user error on installation (aka: my fault).

From what I can see IFI incorporated many of the suggestions that were made over the course of the season which is good to see. I thought they did an excellent job of listening to teams that made direct constructive comments and suggestions and seemed like they really did want to improve the product.

[Alan Ing]

Some teams mentioned that they had trouble with the bearings and that the sideplates were getting bent.

We didn't have this problem and as a suggestion, teams might want to consider modifying the IFI wheel like we did. In our application we weren't confident that the bearing support/sprocket holder would be as robust as we were used to, so we machined solid hubs and spacers to mount our own bearings and sprockets. I know it adds time and weight, but it really stiffend up the assembly. Like I said we only had problems with the three rim sections getting bent, not the sideplates.

We basically enlarged the center hole in the sideplates to 1.125", took some 1.75" round aluminum bar, and turned both ends down to 1.124" leaving the center section at 1.75" drilled and tapped the 1.75" section to mount the sideplates on either side and installed 8mm ID bearings on the two ends of the hubs. 8mm bearings are common inline skate bearings and work great with 5/16" bolts. 8mm = .3149" which allows a good slip fit for 5/16" (.3125" bolts). I know a lot of people advocate 3/8" and 1/2" bolts for wheel axles, but we have never had a problem with grade 8 5/16" bolts when properly supported for wheels (no long spacers between wheel hub and axle mount). Long spacers between the axle support and wheel hub puts a bending moment on the bolt where the spacer meets the wheel. If the hub is long enough to reach the axle support, the bolt will mostly be in shear.

[Madison]

Originally Posted by Arefin Bari

Team 1345 used 2 IFI wheels last year (8x2) and 4 kop wheels. We didn't have any real problem, I must say that the students put it together very nicely. However we were using the kop transmission and not Andy Mark. Even though we were in some matches that were brutal (against 61, wow what a match). matches, I don't think enough torque was applied to the IFI wheels in our configuration to cause any problem. I am planning on using IFI wheels again (after seeing the improved one) and also planning on using Andy Mark transmission. Thank you IFI for providing us with these wheels.

In this arrangement, the IFI wheels see no more torque than the Skyway wheels, so it follows that they're at least as strong as the plastic wheelchair hubs. I don't know if that's saying much, though I've never had trouble with the Skyway wheels.

[AdamHeard]

Originally Posted by M. Krass

In this arrangement, the IFI wheels see no more torque than the Skyway wheels, so it follows that they're at least as strong as the plastic wheelchair hubs. I don't know if that's saying much, though I've never had trouble with the Skyway wheels.

To back this statement up... The last two years we have had 4 cims in the KOP gearbox to a six wheel drive skywheel base. We played aggressive defense both years and have never damaged a wheel.

[Madison]

Originally Posted by cromat44

To back this statement up... The last two years we have had 4 cims in the KOP gearbox to a six wheel drive skywheel base. We played aggressive defense both years and have never damaged a wheel.

Come to think of it, driving Skyway wheels that have been turned down to 'slicks' on a lathe with the provided Kitbot gearing, we've never spun a wheel, nevermind damaged it.