Robot leg sole that does not slip

This rather reminds me of those people who drive extra fast to try to get to a petrol station before they run out. I wouldn't completely write off lowering motor speed - perhaps the traction gained by reducing slippage may outweigh the loss in axle speed, and so actually increasing the overall speed at which the chassis moves.

I'm not sure if anyone fully understands the way friction actually works - I don't think there's any way to tell if two given materials will have a high or low coefficient of friction. Just get hold of a few and test them.

But, if it's a rubber track, that does suggest a couple of lateral-thinking type solutions.

1. Suction pads - if you can get them to work, they could be ideal for gripping a smooth rubber track.
2. Spikes - sharp points that actually dig into the rubber (make sure they won't make you pay for repairing the track first!)

Just a couple of suggestions.

Another, more conventional solution - whatever material you use, just try increasing the area of the feet in contact with the ground, and the weight of the machine. That should have a noticable effect.

Tom

THe study of material vs material is tribology.

lateral-thinking

I tought that was the study of trilobites.

chris in napa

hmmm i definately try a few materials on the track today, and maybe suction caps as well. BTW the weight of my robot is 7.5 Kg and the length is about

lateral-thinking

I thought that was the study of books written by trilobites.

Cheers!

Chip Shults My robotics, space and CGI web page -

Oh- then the study of rubbing explosives on books written by trilobites might be tribotrilobiblioboomology...

Cheers!

Chip Shults My robotics, space and CGI web page -

OK! Now I officially regret my smart ass reply!

chargrinned in napa

Well, Presently I am sooo fried, I can't beat that one. Vascillating between beer and coffee. couldn't decide, compromised instead.

Mike my best shot would be: tribotrilobiblioboomography Recording where the pieces of the poor C4 laden trilobite and his book ended up

grr

Hmmm, I guess the poor, dismembered trilobite that wrote about its studies about rubbing explosives on books would be called an autotribotrilobiblioboomographybiography?

-Brian

I wonder what section of barnes & nobles that book would be in?

chris in napa

And the collection of autobiographies, of those poor trilobites, who died in similar circumstances ...

autotribotrilobiblioboomographybiographyanthology

This is gett>

I'm thinking a silicone based rubber. That can be quite soft, and 'sticky' feeling, even when dirty. The paper pick-up rollers in the copy-machine at work are also this silicone rubber compound. Even while dusty from the 300.000 papers it has already picked up, it still grips.

-- Bye, Ray

How big of a footprint per leg? Go to a sporting goods store and check out the gloves that football receivers and halfbacks wear. 'Bout $25.00 USD a pair. The palms are covered with a material similar(?) to this. Feels sticky, won't rub easily across much of anything. Enough of the stuff that if cut and glued might be just what you're looking for. Haven't tried it just thinking aloud. :)

polyurethane is indeed a good choice but still the slippage problem is there, so currently we are researching on other materials. I have tried silicon and it proved quite effective, somehow it is a bit sticky and soft. Maybe we have got to have a suspension mechanisim on the foot of the leg to absord the shock, and hopefully it can grip better on the surface fo the rubber map. Will be posting the pic of the bot soon, and hopefully the suspension mechanism.

Go to the local library and find a "CRC of Physics and Chemistry". You'll find tables of coefficients of friction (both static/kinetic) between materials. Then with a "possible list", Happy shopping!

Remember that silicon rubber is a really neat material and seems a good choice, but it will cause pretty good drift if you navigate by counting distance traveled.

You may also just want to find an old soft compound tire (used on many sports cars) from a local garage. Take a fine razor blade and "shave" off what you need. It is an excellent material.

Bruce

How about

Washable lint roller, uses a sticky rubber compound.

Also, specialty inline hockey wheels for indoor use often are formulated to be extra soft and sticky.