He is way too late, I have already made one.
This is how I normally make finger engines.

But over on HMEM, I once got a competition going for the fastest build, but it must use a coathanger, or part of one, somewhere in the engine.
It was a great success, and some very novel and unique designs emerged.
Because it was my idea, I didn't submit it for judging, but this one was my contribution, called 'Crusoe', it ran, and still does, very well indeed.

As far as I can remember, somewhere around an hour to make.
Apologies and grovels now being accepted.
Bogs the master chippy.