Interesting you say this, as my ACDC shaker is shit compared to the one I had on my TFLE. I don't have much experience with shakers so now sure what they should be like. The TFLE was smooth and the ACDC is violent like you describe.

I think that might of been me. You have to use an allen wrench to tighten the hex set screws that attach the weights to the motor.
I checked mine by removing the box over the shaker and runnin the shaker in coil test mode. Make sure no wires are in the way of the shaker when you do.

I have to take off my plastic cover or else I get that "rattling" sound.....

You can re-position one of the weights on the shaker to make the two weights less out-of-balance. They are both oriented the same by default. If you rotated one 180 degrees, they are fairly balanced and the shaker doesn't do much, but rotating one about 90 degrees is a nice middle ground. I did that on my Metallica, as that shaker was much more violent than those in my other machines. There is a dimple on the motor shaft where the allen head set screw rests, but I haven't had issues since rotating mine off of this dimple. Just make sure the set screw is tight.

Also, I just fixed a rattle issue on my Iron Man shaker that was not caused by the orientation of the weights. Rather, the motor itself had come loose from the mounting bracket. I used some metal strapping to hold the motor down tight to the bracket and that solved the problem. Let me know if you would like some photos of this. Good luck!

Yes, photos please! Good stuff! No shakers perform alike and many seem poorly tuned or balanced.

Here's a pic. I moved one of the weights 90 degrees for illustrative purposes. On this particular shaker I actually have them set in the default position. You can see the metal strap that I used to hold the motor to the bracket.

Shaker.JPG

+1 did exactly the same