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-   -   How good are your tires?? (http://www.chiefdelphi.com/forums/showthread.php?t=16823)

com 21-01-2003 23:49

How good are your tires??
 
My team and I have been working around the clock to build one of the best drive trains we can. luckly we have finished this new base with some new radical wheels. With these new tires we were able to push one of my mentors around on a steel legged chair on a title floor. We found it very easy to move him around even though our robot only weighted 55 pounds. What do you guys think? Is being able to pull dead weight 4 times your own weight pritty good.

n[ate]vw 21-01-2003 23:53

Quote:

Is being able to pull dead weight 4 times your own weight pritty good.
Not necessarily. Our robot last year had beastly rubber wheels that allowed it to drag a large weight around. The wheels actually gave us too much friction and we had trouble with the motors drawing too much current. You need to find the right balance between good traction and allowing the wheels to slip a little to be kind to your motors.

jonathan lall 21-01-2003 23:55

Well, that all depends on a number of factors. How well can you steer? How good is your lateral traction? How are you on carpet? I'd be interested to know what you've put together.

Sachiel7 22-01-2003 00:10

RAPTAR has selected some nice tires this year...
They are designed for skid steer (our DT) and pivot well, and maintain good friction for the ramp mesh.

Wayne Doenges 22-01-2003 09:10

I concur with n[ate]vw about traction.
Last year we had awesome traction. We used conveyor belt material on 6" wide, 3" diameter cylinders. Our 35 pound base could pull me (205 lb) across the carpet with me laying on my side on the carpet. One problem though, it wouldn't turn worth a ..... well you know.
So you have to play a balancing game between traction and control.
Good luck this year.

Wayne Doenges

DaBruteForceGuy 22-01-2003 11:40

If you think about it, it is quite easy to slide a "mentor" around on a tile (probably lenoleum) floor. We forgo the chair part, and can push pretty much anything around, including mentors, on our slick waxed surface.
Try it on carpet, then you will get a good idea of how much power the drivetrain really has.

com 22-01-2003 12:37

Its not always a trade off for Maneuverability or traction. Often teams solve this with plastic front wheels that will slide sideways. This works but the plastic wheels don't give the best traction. Im not even sure if the plastic wheel idea would hold up to the steel mesh this year. My teams base has extrem maneuverability and probly one of the highest coefficients of friction from the wheels that I have ever seen in my 4 years of robotics. This is all done on the basic 4 wheel drive princiable. Im not telling how we accomplished this but I will give a hint, im sure some of you will figure it out, 'battle bots do this a lot with there drive train'.

Robots and brakeable objects don't mix, Oh and don't let the little 9th graders that don't know what there doing put a medal ruler in your chain and sprocket setup. ARGGGGG what I have to put up with

com 22-01-2003 12:47

If you think about it, it is quite easy to slide a "mentor" around on a tile (probabl
 
probably lenoleum floor...
Yes it is,
Lets just say, the floor is old and needs a good wax job.
Steel on lenoleum reminds me of glass on glass, both smooth but bind very well.

galewind 22-01-2003 13:16

tires with air?
 
We're toying with the possibility of using modified tires that are from a handtruck that will have a significant footprint for better traction (tubeless). We're intending on keeping the wheels fairly shielded. Is having an air-filled tire bad news? Does anyone else use non-solid tires?

It's understood that we'll want to keep a few extra on-hand, but i'm not sure exactly how many of these we should expect to go through. I know those tires are designed to take on a significant amount of weight, which shouldn't be a problem with 4.

All ideas appreciated.

DaBruteForceGuy 22-01-2003 14:36

Re: tires with air?
 
Quote:

Originally posted by galewind
We're toying with the possibility of using modified tires that are from a handtruck that will have a significant footprint for better traction (tubeless). We're intending on keeping the wheels fairly shielded. Is having an air-filled tire bad news? Does anyone else use non-solid tires?

It's understood that we'll want to keep a few extra on-hand, but i'm not sure exactly how many of these we should expect to go through. I know those tires are designed to take on a significant amount of weight, which shouldn't be a problem with 4.

All ideas appreciated.

Yea, pneumatic tires are a great concept, but they are a lil much (if u know what i am getting at). If u look at the reason they were invented, they are made to absorb irregular sufaces on the riding suface. We really don't deal with complications liek that on the rock hard, flat carpet surface. We have all concidered them in the past, but it just turns out to be overkill, the foam insides or softer rubber should be sufficient for the rap curbs and such when it comes to impact and shock absorbtion.

Cory 22-01-2003 15:44

Re: Re: tires with air?
 
Quote:

Originally posted by DaBruteForceGuy
Yea, pneumatic tires are a great concept, but they are a lil much (if u know what i am getting at). If u look at the reason they were invented, they are made to absorb irregular sufaces on the riding suface. We really don't deal with complications liek that on the rock hard, flat carpet surface. We have all concidered them in the past, but it just turns out to be overkill, the foam insides or softer rubber should be sufficient for the rap curbs and such when it comes to impact and shock absorbtion.
Pneumatic tires will potentially have a huge advantage on the mesh...anything that can conform to the surface in any manner will

Pneumatic tires are great. we used them last year, and one set lasted through three competitions just fine...ours were very vulnerable, and we never has any issues with stabbing/popping.

P.S. I'd say that wire mesh is an irregular surface:D

Cory

DaBruteForceGuy 22-01-2003 15:52

Re: Re: Re: tires with air?
 
Quote:

Originally posted by Cory

P.S. I'd say that wire mesh is an irregular surface:D

Cory

:ahh: DOPE!!*stabbs self with pencil*-- your right....
I forgot about that..... But i guess that just because we havn't given the ramp much thought....:rolleyes:

Gope 22-01-2003 16:09

Last year, in low speed, our robot could pull it's weight(130) with a goal (120 i think) with a 160lb engineer laying flat on the carpet floor holding the goal(talk about traction). And the thing is, we weren't even among the strongest robot at nationals.

So, don't expect to be the strongest anywhere you go.

team222badbrad 22-01-2003 16:23

BAH traction is not a problem...

Mike Norton 22-01-2003 20:46

Quote:

Last year, in low speed, our robot could pull it's weight(130) with a goal (120 i think) with a 160lb engineer laying flat on the carpet floor holding the goal(talk about traction). And the thing is, we weren't even among the strongest robot at nationals.

Some teams out here have been working on traction for a long time. If you think you have a strong robot just look at the teams that put everything into their traction and motor train.

We were good in strong last year but was as strong as are track could hold. The Breco flex tracks do rip apart under high loads.

I think the best way of getting the most traction is by a track system. but it will take years of proving different design to come up with one that works.

Traction is good but a good driver will always win over a good robot.


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