pic: 3081 servo operated dog gear

[MrRoboSteve]

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[MrRoboSteve]

Here's the first winch our team has built that includes a dog gear mechanism to prevent back driving. We're using a servo to actuate the dog. It took about 2 hours to build the servo attachment.

Parts:

Toughbox
.090 aluminum sheet to attach servo
servo
.500x.750 aluminum bar
.125x.750 aluminum bar
AndyMark AM-0096A hubs

[TylerS]

Do you have the servo move the bar out of the way whenever you are moving the to drum?

[Jonathan Cheng]

How well does it disengage under high loads?

[Alan Anderson]

What does the servo actuate, and what does the dog gear engage with? I see what looks like it might be a ratchet, but I can't tell how it would let the teeth move in either direction.

[Camren]

It is pretty simple, there is a spring that holds the locking mechanism in place, and as the spindle is spun the lock positions itself in the gear. Then when we want to unwind the spindle. The motor spins just slightly to release the tension on the lock, and then the servo moves the lock into a neutral position allowing the spindle to unwind.

[Oblarg]

Having used (and eaten through) hand-made ratchets before, the one suggestion I have is to keep an eye out for wear and have plenty of spares.