Looking for suggestion on a Gearbox replacement/sub

[ohdan56]

Greetings:

We are looking for feedback/guidance on finding a substitute or replacement for this gearbox:

http://www.andymark.com/product-p/am-2880.htm



We are trying to avoid paying the steep cost (at least in our eyes, LOL) of this part. We are creating some mobile targeting systems for our archery club, and this is our current design solution for the drivetrain that will carry mock deer, bear, and turkey targets around the auxiliary gym.

Any suggestions are welcome, and if someone knows where we can get some of these for cheap, that would be awesome. Cheers,