Robot leg sole that does not slip

Hi guys, currently i am working on a CAM driven robot. The speed is rather fast about 4-5 rotation of the crank per second, thats means the leg will be
dragging the ground 4-5 times. The greatest problem i met is the leg slippage against the ground. As my robot will be used for competition thats is why i could not really lower down the speed. Whats the best material for leg traction? The robot will be running on a rubber track that is rather dusty :( , hence the rubber sole used for chair stubs seems useless.
-- Think the reverse, do the reverse. Pants are shorts that are longer.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

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.

hence
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
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
THe study of material vs material is tribology.
I think the dust will be your enemy, acting like a lubricant.

to
may
I
high
lateral-thinking
they
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Blueeyedpop wrote:

I tought that was the study of trilobites.
chris in napa
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I think that was trilobibiology.....

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I thought that was the study of books written by trilobites.
Cheers!
Chip Shults My robotics, space and CGI web page - http://home.cfl.rr.com/aichip
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
that wouuld be trilobibliology

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
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 - http://home.cfl.rr.com/aichip
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Sir Charles W. Shults III wrote:

OK! Now I officially regret my smart ass reply!
chargrinned in napa
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
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
Mike

trilobites
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 18 Sep 2003 00:00:54 -0400, Blueeyedpop wrote:

Hmmm, I guess the poor, dismembered trilobite that wrote about its studies about rubbing explosives on books would be called an autotribotrilobiblioboomographybiography?
-Brian
--
Brian Dean, snipped-for-privacy@bdmicro.com
BDMICRO - Maker of the MAVRIC ATmega128 Dev Board
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Brian Dean wrote:

I wonder what section of barnes & nobles that book would be in?
chris in napa
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
And the collection of autobiographies, of those poor trilobites, who died in similar circumstances ...
autotribotrilobiblioboomographybiographyanthology
This is getting silly I like it.
Mike

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
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 500mm its a 12 legged machine
-- Think the reverse, do the reverse. Pants are shorts that are longer.

to
may
I
high
lateral-thinking
they
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

be
hence
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
http://home.hccnet.nl/raymond.van.elst / Mobile robot, walker and I-Cybie
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

rather
will
silicone
still
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. :)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

How about http://www.walgreens.com/store/product.jhtml?PRODID 637&CATID0760 ?
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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
polyurethane is alos a good choice, and available in a wide selection of durometers.

rather
will
silicone
still
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
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.
-- Think the reverse, do the reverse. Pants are shorts that are longer.

my
lower
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
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

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.