pic: VEX Pro Winch 'Dog Gear'



It’s a dog gear!

Or some other such orthogonally translating torque transmitting rotating mechanical device.

That’s a very… interesting “dog gear.”

How much torque is on it? How well has it held up in testing?

I like it.

I’d wager it can handle a lot of torque.

If you have any issues with it disengaging, replacing the nuts with something more smooth would likely help.

Wow, I like it. Very simple design. I see that you have two hubs with bolts and nuts to make them catch. I’m having a hard time seeing how it’s released. From the picture it appears that it’s released by actuating the gearbox. Is that right? If so, are the winch and the gearbox on completely separate shafts?

Is that a ratchet wrench I see on the shaft next to the gear box?

And nice move on bolting the seat belt material (which is what I presume it is). Practice robot?

That assembly looks familiar! (Student on the team here)

We have a 100:1 gear ratio coming off the bag motor. We are going to test a 70:1 ratio on the practice bot to increase winching speed but that may not be implemented.

As far as testing goes, we went to a pre-bagging scrimmage last Sunday and practiced for about 3-4 hours. The only mechanical problem we had was that the hub on the motor side became loose due to the set screw loosening…we put a much larger set screw in. Problem solved.

If you look behind the bag motor and the versa planetary gearbox, you can see a pneumatic cylinder. That is actually what engages and disengages the whole winch assembly.

The motor is mounted to a linear slider. The cylinder is mounted to the motor via the custom brackets and then attaches to the launcher frame on the left. When the cylinder fires, the entire motor assembly with the motor output shaft slides into the engaged/disengaged positions.

The right side of the assembly is a separate shaft from the motor output and is hard mounted.

That is a ratchet! It really helps reduce the winch from turning in the wrong direction once the shooter is cocked.

We are building a practice robot. Rebuilding the launcher from scratch with a few tweaks in mind. The assembly pictured is on the competition bot.