looking for source of counter rotating props

I am looking for a source for matching left/right - clockwise/counter clockwise propellers for an engineering project. Motor speed can be adjusted for either trolling motor props or equivalent of a small outboard engine (prop for 1 to 6 hp outboards). Great posts here discuss the outward vs inward rotation of the dual props. That is what I want to test as a school project.

And help or suggestions for propeller source is greatly appreciated.

 

Counter rotating propellers so small are going to be hard to buy. If you can make a CAD file, a 3D printer can get it done in a couple of hours.

 

Thanks Gonzo - that seems to be a likely means of obtaining them. I'm guessing there would be a way to flop or mirror the design for an exact match.

 

Flipping a CAD is really easy. Where in WI are you?

 

APC makes a matched pair of 20.5 x 20 and 20.5 x 22 contra rotating props. My assumption is that the aft prop needs slightly higher pitch to get best efficiency.

You could cut them down or use them as is if your motor does well at less than about 400 rpm. Solar or human power is where I think those props could work well.

 

literature

http://www.cembercimotorserviskitaplarikutuphanesi.com/propeller-type.htm

literatures are available on this page
oktay çemberci

 

Are you looking for counter rotating props on the same shaft or just a left and right hand pitched prop of equal pitch

 

Try tower hobbies (dot com) for pusher and puller model airplane props up to perhaps 16" diameter. Selection might be limited in 3 blade designs. Assuming you can handle the gearing part, the props themselves are quite inexpensive.