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View Full Version : Are bolts to hold wheels on, and bearings, considered "fasteners"?


kmcclary
10-19-2001, 09:12 PM
1) Using 1/4" rod is a rather flimsy way to support a wheel. Now fasteners are unlimited, as are hinges, but can we use 5/8" bolts to bolt wheels right to the chassis instead of working with that cheezy rod? (Hey, it's still a fastener, isn't it? :-)

2) The rules say we need to protect the motors. We found two Keyangs and one drill motor in the kit with bent shafts from previous competitions, forcing us to make another trip to Pontiac. We'd like to use something "bearing like", such as a cheap skateboard bearing, to float or support an idler shaft of some kind so that we can PROPERLY unload the motors. Is a bearing considered a "fastener"? If not, would that be allowed? Personally, I'd love to see it was easy according to the rules to protect the motors, and eliminate temptation (or excuses :-) to torture motor shafts.

- Keith McClary, Huron High Team 830

Mike Martus
10-21-2001, 11:52 AM
You have already been contacted regarding the parts that need replacing.

For all other teams:

This is the 3rd year on the kit of parts. We replaced many of the smaller items but we are reusing the motors as they are a large expense along with the controls.

I preformed a visual inspection of the many motors in the 24 kits. I removed damaged motors and replaced them with new from stock. It is possible that there is damage that I did not catch.

We ( Joe Johnson, Hassin Anahid and myself) also did a full operational check of the control system to eliminate problems.

We will provide replacements as necessary.

Just call me 810-402-0317 (pager) and I can make arrangements for you to get them.

We would prefer that you do NOT wait until the day of the competition to swap parts. That is a lot of stress on everyone.

kmcclary
10-21-2001, 01:46 PM
Oh, you've been great, Mike! This thread was definitely NOT to complain about service in ANY way! (And thanks to all for all of the answers to the questions in the other threads! :-) We're dealing with our own part problems on the side.

I was stating part problems as a WARNING to other teams that given how some of these motors wobble now, they obviously have NOT been able take very high side force loads previous competitions have imposed on them, and your warning should be taken VERY SERIOUSLY! <grin> The shaft's metal is either softer than everyone thinks, or else we've REALLY been torturing these things, and the playing field activity is wilder than expected!!!! <grin>

Either way, I would like to explore what the "preferred" method of shaft supports should be to prevent the motor shafts from bending and suffering excessive side forces. My question was to find out what IS legal WRT bearings, and whether bolting on wheels with regular BIG bolts instead of dinky 1/4 shafts IS allowed.

So, how about it? Can we use some big honking stove bolts and washers to attach wheels? Are roller blade / skateboard bearings or other REAL bearings considered shaft "fasteners "or "hinges", or are they all banned and we have to support wheels only using 1/4" shafts and sintered brass bushings?

- Keith McClary, Huron High Team 830

meaubry
10-22-2001, 10:35 PM
Keith,
After talking with Joe J. and Mike M. - we have decided to allow fasteners to be used as wheel axles under the following conditions.
1) NO MOD parts must remain unmodified, don't drill out the center hole on the sprockets to get a bigger bolt through.
2) No precision machining rule remains intact
3) The supporting a motor shaft rule does not change - please support the motor shafts so as not to bend them.

Remember, fasteners are intended to be used to "fasten" - that is there primary purpose - in this case we are going way outside the bounds of the fastener rule, to primarily make building the robots easier and more convenient for everyone. This is suppose to be fun, right?
Bearings used must comply with the rules as written. I would say that bushings are okay, but I don't think roller skate bearings are on the additional hardware list.
Hopefully, this ruling will not cause anyone harm - we didn't intend it to. We are hoping it will help.