Electric Multi-Ratio Rod Drive Prototype

I’m developing a bench-top research rig that needs to spin a 10 mm carbon-fiber rod through a range of gear ratios roughly equivalent to a 21-speed bicycle. The idea is simple: an electric motor drives a chain, the chain engages a compact cassette of sprockets, and I can manually select the ratio just as you would on a bike. What I don’t have is the mechanical design, component sourcing, and fabrication expertise to turn that concept into a tidy, reliable prototype.

Here’s what I’m picturing. The whole unit should fit on a small test stand, plug into a standard outlet, and let me shift through every ratio with a positive, hand-operated mechanism—no electronics or automation required beyond the motor itself. The output shaft (Ø 1 cm carbon-fiber) must stay true and vibration-free while transmitting whatever torque those gears can deliver. Because it will live in an R&D environment, repeatability and ease of disassembly for measurement are more valuable than polished aesthetics.

If you can handle the mechanical design, motor sizing, chain/sprocket selection, and final assembly—or guide me through a build-it-myself kit—let’s talk. I’ll need:

• CAD or detailed drawings
• A complete parts list with suppliers
• The finished, test-ready unit (or a clearly documented build package)