Pulling Cars

[M4 Sherman]

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.

[MGoelz]

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

[Scott Morgan]

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.

[Joe Ross]

http://www.chiefdelphi.com/forums/sh...ad.php?t=55032

[FunkyRatDemon]

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)

[Qbranch]

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

-q

[mtaman02]

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.

[Qbranch]

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

[Protronie]

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.

[WernerNYK]

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...

[willy_d]

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

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.

[Qbranch]

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...

thank goodness for water and elbow grease

-q

[bigbeezy]

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).

[KTorak]

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