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.
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.
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)
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
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:
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…
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.
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:
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).
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.
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.
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??
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: