Bouncing turns

[Sachiel7]

Well, at the DC Scrimmage last Saturday, I saw quite alot of bots w/ this problem...
Luckily ours wasnt one...
But anyway, the 12" pneumatics wheels seem to be used ALOT this year. Mainly, I would assume to climb the platform from the side, which based on last weekends results, isnt going to work quite as well as people would hope...
We personally stick with our 8x2" wheels, spaced out 26" wide (roughly)
I'm not too sure how to eliminate the issue. If you're not planning on going up the platform, try to get some smaller wheels with a little less traction. Or, you could make 2 big omni wheels for the front or back 2 tires of your bot using a bunch of smaller omnis.
I would make sure your tire pressure is full though. That was an issue with a few of the 12" 4x4 bots...

[blindguyinanorg]

someone posted earlier that they painted the back wheels with poly somthing or another. the robot will rotate around the front wheels because the back ones slip.


also with the tire pressure deflate the front ones and inflate the back ones. you want it to rotate around one wheel set and slide the other.

we just stuck some casters on the back that come up when we are climbing the platform

[Elgin Clock]

Somoene actually suggested using a wax type substance like armor-all on the tires? Would that work, or be legal?

[blindguyinanorg]

Originally Posted by Elgin Clock

Somoene actually suggested using a wax type substance like armor-all on the tires? Would that work, or be legal?

yes, anything to reduce the friction

there is another post about this(by me) but it ended up in the pnuematics section sence i said pnuematic wheels HA!

http://www.chiefdelphi.com/forums/sh...ad.php?t=25061

[ChrisH]

The Schmoebots had this problem as well. They solved it by simply removing the tires on one end and running on the rims. There's a little bit of slip from the different diameters, but it doesn't seem to cause any problems.

[Greg Perkins]

Originally Posted by ChrisH

The Schmoebots had this problem as well. They solved it by simply removing the tires on one end and running on the rims. There's a little bit of slip from the different diameters, but it doesn't seem to cause any problems.

or make a wheel outa lexan or delrin

[Ruffryders1273]

Originally Posted by Jones571
This was a problem at the UTC scrimmage 716 was bouncing out of control they didn't have the problem as bad after taking most of the air pressure out of there tires.

We did have this problem but after our first match we deflated our tires to the recommended 35psi(instead of 50psi), we still get some bounce but only in low gear.

[Random Dude]

Originally Posted by Elgin Clock

Somoene actually suggested using a wax type substance like armor-all on the tires? Would that work, or be legal?

Hmm. Well, I would think wax could be a bad idea, since it could(would?) rub off easily onto the carpet, something which FIRST would not like.

However, what does work, is wrapping some sort of material around the tires...

[Collin Fultz]

we had this exact same problem last year. the cause was too much top weight and too much traction. we looked like we were convulsing while turning. we could never figure out how to stop it and just kind of lived with it. on the bright side...we never lost a pushing match. good luck!

[Peter Matteson]

My team, 177, has perrenially had this issue we finally broke down and made omniwheels for the rear. Our experience shows that having lower friction in the rear wheels increases manueverabilty while retaining control compared to the fronts. Most teams who saw our bot at the UTC scrimmage can attest to it's speed and manueverabilty with these wheels. We were also never at a loss for traction.

[Eric Bareiss]

Originally Posted by Elgin Clock

Somoene actually suggested using a wax type substance like armor-all on the tires? Would that work, or be legal?

No you can not do this, once again a case of "if you don't know don't answer"

<R15> Lubricants may be used only to reduce friction within the robot. Lubricants shall not be allowed to contaminate the playing field surfaces, balls, or other robots.

You can use anything that will stay on your wheels, tape, paint, glue. But nothing that will rub off and contaminate the field.

[Kevin Karan]

wax wont rub off. Though you would loose so much traction that you probably wouldnt be able to climb to the bar anymore.

[gnormhurst]

I assume everyone is talking about 4-wheel-based bots. I guess if you were surprised that it wouldn't turn well, the lesson is to think carefully before committing to a major design decision.

Our bot has only two wheels, midship, and plastic skids on the corners. It turns nicely in any radius we choose and turns on a dime.

And it can't climb the steps at all. Engineering is the art of making tradeoffs. We'll go for the bar from the side.

Has anyone built a bot with a rear-end differential and steered wheels like a car?

[ngreen]

Originally Posted by Eric Bareiss

No you can not do this, once again a case of "if you don't know don't answer"

<R15> Lubricants may be used only to reduce friction within the robot. Lubricants shall not be allowed to contaminate the playing field surfaces, balls, or other robots.

You can use anything that will stay on your wheels, tape, paint, glue. But nothing that will rub off and contaminate the field.

Be nicer than that. You can use anything that will not rub off on the field. Armor-all when used right won't damage the playing field while making your tires a little slicker. I wouldn't reccomend it though. However tape may not be used. The only tape that is allowed is electrical tape as an electrical insulators. I don't want to be offensive about this but it is not good to post about someone else not knowing the answer and having incorrect statements in your own comments.

[jparkteach]

It has been posted elsewhere but our team came up with it early on during the design stage once we realized that we might have some problems turning. Zip-ties on either the front or the rear wheels. On all four wheels is overkill, you may want to put them on the wheels farthest from the center of gravity of your robot in order to keep as much traction as possible.