First time using Driven Key - Can't seem to get it working.

[layomayolayo]

I have a simple working crankshaft rig utilizing two aim constraints, and two point constraints. I want to set the rotation of this main shaft to drive the rotation of the other parts. How do I get this to work? Or, is there an easier/better way to do this? I am new to rigging, so any help is appreciated. Attached is my scene file. Thanks!

[osidedan]

orient constraint is what you want 🙂 
Orient constraint is a fancy way of saying rotation constraint. Select the main shaft(polySurface119 as it's called in the file you provided), then shift select the first crankshaft piece you want to control. Go to Constrain>orient>option box. Use the following, settings:

To continue constraining the rest of them, just repeat the process. select the main shaft (polySurface119), shift select the next crankshaft piece, do the constrain. Repeat until they're all constrained. I'm attaching a video to show what it should look like once you've done them all. Let me know if you need any more clarification on that!

Edit: I just noticed you mentioned set driven key. Is this for a school assignment? if so, and your teacher wants it to be done with set driven keys let me know, I can elaborate on that method as well. It's just a different way of doing it.