Help building something that will go back and forth

[Bighooveman]

Hey
I was wondering if you all could help me. I need to build something that will move a rod of wood back and forth in a fashion similar to a musical metronome.

I am hopeing to make it for under 50 dollars and need it to go about 200 rpms at min.
____
l l
l l
/ l l <----Wood Rod
/ l l
/ l l
/ l l
/ l l
V l l
____________________l___l______________________
l l
l_____________________________________________l

Any help would be greatly appreciated.
Base

 

[russ_watters]

all you need is a small electric motor, perhaps with a reduction gear, and a single linkage attached above the pivot point. Try a hobby shop.