Van door motor cad?

I’m trying to make a cheese cake mechanism that needs a worm and wheel and we have the old kop van door motor and wondering if anyone has cad model or drawings

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Maybe this thread will be useful?

There were two products that I recall, one is a Bosch motor, the other was made by Taigene. There was also a left and right so be careful in that regard that you are working with the correct one that you have.

It’s generally a really strong motor but be aware of a few issues.

First, the shaft has a softer steel. We created a planar groove to mount a sprocket to it and position it by set screw, the set screw eventually dug it’s way all the way around the shaft. We found better results by making a recess hole for the set screw to make it more difficult to slip. Definetly don’t rely on a set screw pressure solely to hold a hub or sprocket in place on its shaft.

Second, the gearbox case is susceptible to shock. We cracked one wide open in competition and the gear and main shaft separated cleanly off the main housing. I should qualify this to say that I suspect it was the way we mounted it that put it at risk as I think we only mounted it by two bolt holes rather than the three it came with.

The motor specs are here. Maybe there is something more versatile in the same range.

https://www.google.com/url?sa=t&source=web&rct=j&url=http://first.wpi.edu/Images/CMS/First/2008FRC_Van_Door_Motor_Spec.pdf&ved=2ahUKEwiC1cv4g8nZAhUHKqwKHbPfBd8QFjAAegQIBhAB&usg=AOvVaw2DxtK5DIRmd8dLoTYDCvfQ

I will say however, it took significant abuse and punishment and you will likely want to put a length of chain between it and whatever you are driving. And it can be backdriven but not easily. You’ll want a spare if you don’t have one

Thanks in my case it’s in a well protected and shock resistant area, do you have any recommendations non how to mount a vex gear to it

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We used a pair of set screws to couple a sprocket, but I did not know of the shaft issue above. Might think about drilling through the shaft and putting a bolt through it.

Set screws aren’t made to hold onto a round shaft. You’ll want to machine a flat onto the shaft that a big wide set screw can sit flat against. Keep in mind, though, that if you modify the motor shaft (either by cross-drilling it or machining/filing a flat on it, you cannot use the motor in future years). Use as big of a set screw as you can and as wide of a flat (without going overboard) so you get as much flat-to-flat contact between the set screw and the shaft.

if you’re still rounding over the shaft, you might want to re-calculate the force/torque you’re putting back on the motor. I’m going to generalize, but most motors are made with output shafts that can withstand their rated torque.

If you have a load with high reflected inertia on the motor, if you try to accelerate or decelerate too quickly, you can slowly start wearing the shaft, and every time you accel/decel, you’ll make it worse until you finally gouge a groove all the way around the shaft.

How about that … the FirstCadLibrary lives via the waybackmachine … I just downloaded one of my models as a test … too funny. :slight_smile:

The Taigene motors have a D-shaped output shaft end.

That’s good. I’d recommend to use as big of a set screw that will fit across the flat. Also, don’t use pointed or cupped screws, use flat-tipped set screws.

If that still gouges out the shaft, really do the calculation of reflected inertia and torque on the motor shaft.

We did that. That’s what the “planar groove” I said we created was for. I suspect that the set screw did not have a flat face though. When it gouged the surface it didnt just gouge it, it literally reshaped the metal like a plow row lifting or pushing the sides of the gouge up and over and seizing the sprocket onto the shaft. That why I characterized tbe steel as softer than I might have expected. It didnt just scrape or shave it, it deformed the metal.

And yes it did have the “d” shape on the end but it was pretty useless being on the end. I think if I were going to mount anything Vex on it I’d try to mount a versahub first. I cant recall the shafts diameter now but I think I would try cutting the shaft down to maybe an inch or inch and half and shape it to fit a versahex adapter d bore or square bore and use that to position versahub with hex bore on two adapters. Just make sure you don’t shorten the shaft too much, you’ll want space for a clamp on the end. Or keep its full length and support its end with a bearing mount.

Bear in mind that the steel shaft is integrated with the plastic gear on the inside. If you alter the shaft you should be aware that it’s not all steel. But honestly I don’t think you can harm if. We destroyed the outer casing, broke it into two seperate halves, before we were able to put it out of service. Which is what left me with the sense that the motor was significantly more powerful than the it’s supporting hardware could withstand. It was made to mount to a door regulator, not a robot :slight_smile:

This is essentially what I try to preach to my students: Don’t mount things directly to the motor shaft.

The stackup I try to push is: motor > shaft coupling > shaft that is supported by 2 bearings (one on each end), then you mount your sprocket/whatever to the secondary shaft. I’d rather replace a $5 shaft, then a $80 motor output (in industry, motors can get even crazier in price so the example is that much more enhanced). Ideally, your motor should never see any force other than the drive torque it is supplying. Our first year, we mounted sprockets directly to the output of a PG188 and pretty much destroyed the motor, both by the set screw digging into the shaft (similar to your situation), and also by putting too much side-load on the output shaft.