Van door motor

[Ben Fitch]

My team may be using the van door motor this year. I was wondering if anyone has any pictures or knows how to hook this motor up to a shaft or something usefull.

[Raul]

The shaft on the van door motor looks like it is hardened, but is is not. It is pretty easy to mill a keyway slot or double-d on it and cut it to the length you need. As an alternative, if you have limited machining capabilities, try using a "trans-torque coupler". In this case you need to find the appropriate size for its shaft diameter.

[jdiwnab]

We used the Van Door moter last year. We attached a large sprocket to the shaft that is on the output side. A word of causion: the moter may be strong and may have a worm gear, but it also has a break that prevents both the gears from breaking and from it exceding about 30 ft-lbs of torque. We had the moter directly contolling our arm last year with about an 8:1 gear ration in the sprockets but it was too much for the van door and it couldn't lift the arm very much and was very hard to control . For lighter uses, like pulling and the like, the van door is very good, but don't try to control a large arm with it like we did.

[petek]

Cybersonics used the van door motor to drive our telescoping tower last year. We had it driving a linear chain attached to one section. There is a little info on it in our 2004 Inventor submission . There are a couple of animations at the bottom of this page which show how we used it, though not in detail. There's also a video of it working.

We put a 20T sprocket on the motor shaft, driving a 38T intermediate, connected by a shaft to a 24T which drove the linear chain. The linear chain & sprocket worked just like a rack and pinion, except we wrapped the chain half-way around the sprocket.

In this configuration we could lift the robot at about 1 ft/sec, and were able to llift ourselves with two other robots part-way on us. The tower drive was one of the most reliable parts of that robot. In testing it lifted over 200 lbs. Which, btw, is way beyond what the FIRST torque specs say it should be able to do - by a factor of three!

[Joe Johnson]

The van door motor is a great motor but it has some limitations.

#1 it is thermal protected which means if you stall if (or run it near stall) for too long, it will give up. This makes it hard to burn up but a pain if you really need to lift and the circuit protection will not let you.

#2 It really does not like running into a brick wall. If you are running it at full speed and your arm hits its end of travel stop, it will let you get away with it a few times (under 6) but not much more than that. After that, the teeth will have a noticeable bend to them (if you pull the cover to check them out) and you can actually see the motor slow down as that section of teeth mate with the worm gear (this is very obvious at low voltages).

Other than that, it is a pretty good motor that can give you many matches of useful, reliable service.

Joe J.