Small wheels are on the floor; big wheels are “floating” and can spin freely. We shift between low-gear and high-gear using pneumatics. The robot shifts smoothly, even if another robot is try to push us around.
Nice looking robot. That suspension looks amazing!
Are those zip ties on the front wheel? I know METAL can’t be used as a traction device, but those might rip up the carpet just as bad.
Yep, those are zip ties.
We tuned our wheel coefficient of friction with them to allow tight turns in low gear. The robot pivots about a point just inboard of the wheels with the conveyor belt material attached. The wheels with zip ties are slick enough to slip easily in the turn. We haven’t see any sign of damage to carpets when driving on the big wheels.
i would be nervous that if those zip ties rotated around a bit that they could easily snag the carpet and possibly get a dq, or that they could penetrate the plane of the mesh and get a dq that way.
I think I’m in love with your drive train.
We used a zip tie tool to get them very snug - the remaining rubber on the edges of the wheel holds them in place quite well.
But we will check them after each match just to make sure they’re secure. Thanks for expressing your concern…
zip tie tightening/cutting tools RULE the world!
We had one…but then when a bunch of the rookies reorganized a bunch of stuff before build season that and our stock pile of zip ties disappeared…we all cryed together for awhile…
I love this bot though! Great work!
We used Zip ties on our wheels last year. They work great and do not damage the carpet (at least in the configuration we used, with the smooth side of the tie out and the closing “zipper” off to the side).
HOWEVER…
According to the FIRST Q&A forums:
POSTED QUESTION:
Wire ties on wheels Posted: Jan 15, 2003 12:05 PM _
Regarding rule M17 under Robot Rules, it states, “Traction devices may not have surface features such as metal or hard plastic studs, cleats or other attachments.” My team is not quite clear on what corresponds to hard plastic studs. Would wire ties attached to wheels horizontally across the wheel be considered hard plastic studs or cleats?
[Edited by: first on Jan 15, 2003 12:25 PM]
FIRST’S OFFICIAL REPLY:
Re: Wire ties on wheels Posted: Jan 15, 2003 12:29 PM _
Yes, wire ties attached to the wheels would be considered hard plastic cleats. The problem is that we have seen these systems used before and we have seen them damage the carpet. I question how effective this system would be on the wire mesh or the HDPE.
36F
Sorry to bring bad news, but we wanted to do this to our wheels also. Had to come up with an alternative.
-Mr. Van
Coach, Team 599
*Originally posted by Mr. Van *
**FIRST’S OFFICIAL REPLY:
Re: Wire ties on wheels Posted: Jan 15, 2003 12:29 PM _
Yes, wire ties attached to the wheels would be considered hard plastic cleats. The problem is that we have seen these systems used before and we have seen them damage the carpet. I question how effective this system would be on the wire mesh or the HDPE.
36FSorry to bring bad news, but we wanted to do this to our wheels also. Had to come up with an alternative.
-Mr. Van
Coach, Team 599 **
Wow! Thanks for the warning. I am glad that we didn’t find that out in Phoenix, but I certainly wish we had known about it earlier. I guess that some of the answers to questions do not come out in the updates, contrary to my understanding.
We will have to review all the questions and answers on the FIRST Forum.
In the meantime, does anyone have any ideas on what we could use to reduce our side friction instead of cable ties? We pop fuses like mad without them.
You could always construct some omni wheels. You might bee able to get some tips on them from people like team 857 or technokats (just a few off the top of my head).
try cutting notches intot he wheels or rubbing them with sandpaper cus then the wheels start getting ruff thats what they do on nascars you should try it it worked good fro us last year
I could understand the response from FIRST if the locking heads on the cable ties were on the outside of the wheel. Then the cable ties would definitely behave as “cleats”.
In the configuration we’ve attached the ties, they do not protrude through the wire mesh and, in hours of driving our robot, we’ve not seen ANY evidence of damage to the carpet.
But we will find an alternative way to REDUCE friction for those wheels…
Very nice “anti-transmission.” 
I’m really glad to see that someone, somewhere has employed this system of shifting this season. It’s really a wonder to watch, and after my experiences with a ‘traditional’ shift-on-the-fly transmission, it’s a system I’ll look into perfecting for our own uses.
Thanks for sharing pictures