[partsman]

that would be great but first i need to learn how to build a crank arm.
Thanks so much

No problem there just go to this link: The Flying Crank Ghost - Instructions, Part 1 Doug has a great description of a crank arm for a motor for his flying crank ghost along with pictures. You can do this no problem.

 

[partsman]

But even the motor to a head dropper is still a motor that turns, it just goes in two differtent directions, you can still achieve this effect with a one way motor.