Pulling Cars
 

My team got our robot back today, and we decided to see if it could pull a person in a cart. The robot did it with ease. Then we decided to pull my Toyota Tacoma 4x4 with a nylon strap. To our amazment, it actually worked, even with three people in the car.

So I was wondering if any other teams have tried to pull anything heavy with their robot.

Re: Pulling Cars
 

I can't say that we have.
I think we are too emotionally attached to our robot to risk any destruction.:D

Re: Pulling Cars
 

There used to be a truck pull competition at one of the off season competition events our team attended. Whoever could pull the truck the farthest won. They haven't held this event for years though.

Re: Pulling Cars
 

Re: Pulling Cars
 

The biggest thing we've pulled is my Co-lead in PR and Marketing, Brannden. He is a big guy, we call him "three and a half people", we've pushed him w/ our amzing tracks

(and me in the mascot costume around the commons on a wheely cart)

Re: Pulling Cars
 

Our 2006 shooter pulled a 2500 series GMC pickemup truck a good distance... we stopped because we were lauging too hard... :yikes:

-q

Re: Pulling Cars
 

Now thats a big truck, do you guys have any video / pictures of it. I do recall that 2500 GMC Pickup being a heavy vehicle.

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Unfortunately no... it was a spur-of-the-moment type thing...

really, its not surprising that it did pull the truck, we were using a gen1 am pneumatic shifter and then you factor in the 2:1 reduction in the sprockets, i figure we had about 50lbs of pushing force, so, if the truck's in neutral and the parking lot around MCC (our place of robot work), it shouldnt take a whole lot of force to move. its allll about the bearings then ;)

-q

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I once pulled a overloaded C-30 Chevy 1-ton van cross a parking lot on a Honda XR-600. I'd love to see a robot do that.
Better yet... I can get my hands on a Kenworth tri-axle dump truck if you want a real challenge. :eek:

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I'd argue that the largest limiting factor here would be the traction of the robot's wheels with whatever surface it is driving on. Weight of the robot will also come into play in determining the frictional forces...

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turns out, wearing sneakers, on a nice day, with both arms... i can overcome a little static friction too!

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I push cars around every day in my Auto class...

It actually doesn't take much force at all. The only real factor (as mentioned by someone above me) is the wheels, and whether or not the robot can pull without losing grip and spinning wheels.

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Our '06 Robot had some nice wide BrecoFlex tracks and those signature FDM sprockets we love to use... no traction problems there.

which reminds me... once i was driving the '06 robot in 2nd gear (14 ft/s) on the huge basketball court at one of the high schools in our township... on those nice smooth floors you sure can get some speed... it was all fun till i tried to take a turn and made some chainsaw-looking-skid marks on the floor thanks to the tracks... :ahh:

thank goodness for water and elbow grease :o

-q

Re: Pulling Cars
 

sounds like a cool idea.

our robot from this year could probabily do it with its AM 2speed with servo shifter, 3:1 gear ratio with the sprokets, 2 small CIM's/side, and our wheels are 8" solid Mahogany 2" thick with the IFI high traction tread. ya it should be able to pull a car.

once you get the wheels on the car moving its pretty easy to pull (as long as no resistance is being added with distance).

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My sophomore year on team 93 at the championship in Houston; after we didn't get picked we pulled a 18 wheeler with trailer around the parking lot of the Astrodome with our bot.

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624 has had two robots with very strong drive trains.

Our 2002 robot (Tankbot) pulled a car in a parking lot. Unfortunately there is no record of this. Here is the five wheeled tank in an unfinished state:


Our 2006 shooter robot had an unbelievable amout of traction (neoprene coated wheels, which ended up not being the best idea). Here it is pulling Kyle (~135lbs across carpet, low gear, full contact).

In addition, here it is pulling Mr. Pramik, one of our mentors that year (~250lbs across carpet, low gear, full contact).

Those might not be the same as pulling a truck, but there is a whole lot more friction to overcome.

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Now thats pulling power! :eek:

Where was your robot when I paid $350.00 to have my rig towed less than five miles? :D

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Actually, Eric is a bit mistaken. We pulled a semi tractor without the trailer. We did pull a Ford F350 with our team trailer hooked up behind it. We've got video footage of it on our school's server. I'll put it on our team's website and post a link to it on Monday.

In all honesty, the only issues are having enough weight on the robot and enough traction from the wheels to the ground. As it turns out, just about any rubbery material will grip asphalt very well. Then all you need to do is overcome the resistance of what you are trying to pull and once the vehicle (or whatever you pulling) is moving it is fairly easy for the robot to keep it going.

I like the idea of a tractor pull with robots. Could this be an IRI event in 2008??

Sean

Re: Pulling Cars
 

We haven't pulled much w/ our robots. On the other hand, it's really fun to stand on our older robots and ride around. Sometimes we chase people too, (but only as a joke). DONT USE ROBOTS FOR EVIL!!!:ahh:

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As promised...

This is video from 2003 when our robot towed an F350 and our team trailer along with a few other vehicles.

http://www.aasd.k12.wi.us/Tesla/firs...2003Movies.htm

Like I said before, its not as tough as you'd think.

Sean

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NICE!

-q

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You guys have way too much time on your hands =). Good to see the 2003 robot still going strong.

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I have actually had that on a "would be cool" list for a few years.
They make small sleds for use with 'person powered" tractor pulls.

if we only had a little more time......

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Robot tractor pulls might make good entertainment at IRI.

Congratulations on your 931st post, Chris. :D (My favorite number!)

Re: Pulling Cars
 

Although it's not as exciting or interesting, a bathroom scale on a solid wall and a patch of carpet could be used for the same purpose. If another scale is added for weighing robots, you could then pull coefficient of friction numbers instead of raw pushing force, which would make the 5 & 6 foot weight classes able to compete. The downside being, of course, the pushing power competition is not a spectator sport.

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I've gotta try this with our 2006 Tank (nickname) robot...I bet it could pull at least a car.

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Team 348's 2006 robot, "The Commander", with 12 wheels, pulled a 87' Dodge Dakota. It could have pulled more, but the wheels and hopper are not connected, but all connected to a metal rod. The wheels were moving so much, that they could not keep a grip when we added a 2002 Chevy Avalanche. Our 2007 robot could do it, but with an eight of an inch clearance, it bottoms out very easily.