Gonna build a mallard machine, never seen one though besides on the www. My question is how does it work? Is the prop sucking the
Decoys under? Do the legs have to fold or can they be stationary?

Yes the prop pulls the the frame down, which in turn pulls the decoys under, and water shoots up making ripples. Attach the string to the front of the keel so that it pulls the front/head of the decoy under water. the arms can be stationary. You can just make a square frame and brace the trolling motor in the middle of it and then attach you decoy stings to each of the four corners of the square. make sense?

Yes it makes perfect sence, thank you

Try not to make it too heavy cuz when its just sittin in the water it will have half of the body of the decoy pulled under water.

I just found this, should give you a good idea, I like it better that the square frame idea because it is collapsable. http://www.duckfever.com/mallardmachine.html

Yea ima make it look exactly like the real one do u know where I can get an old motor for hardly anything?

i'de actually put the string 1/2 way between the front and the middle of the deek. It sits much better when not using the prop and when you do hit the prop it pulls down more like a feeder. If you tie it to the front it will constantly pull down on the front of the deek making it look unnatural when not using the prop. But if they get that close you need to have shot them already.....

Yea my buddy suggested the same thing, thanx for the input