ASP180 4 stroke Prop Dilemma

Briefly here is my conundrum. I have a 180 4 stroke (30cc) laying around. The model I planning on using it in would need a pusher prop. Previously the engine had various 2 blade props in the 17 - 18 range (Super Chipmunk). But the present project requires a pusher and three blades. Possibly 16 x 3 x 12? But where from? Large IC props in pusher format are like rocking horse s**t.

If I can not solve this little problem the alternative is a 2500W electric motor, HV 120 ESC and a pair of 5 cell lipos, all extra expense.

I've seen a propeller system on the Internet. It has an alloy hub, available in three and four blade types. Has the advantage of selectable pitch settings via a supplied key, the blades come in various lengths and styles. Just wish I could remember the maker, think it was German. Pretty sure you could find it on Google.

Phil F51 told us of his dilemma

If I can not solve this little problem

How about looking into having the 4 stroke re-timed to run "backwards" which would then allow you to use a conventional tractor prop as you would if you went electric?

Brian - I think your talking Ramoser Vario props. Got one already for the PC21. Good but expensive. But they are not "pushers".

David - Now that's an idea if possible. I would think the cam shaft would be reversed somehow. I'll speak to Just Engines later see what answer I get.

Phil informs us that

I would think the cam shaft would be reversed somehow

I had assumed that the inlet and exhaust cams would be driven separately as in Laser engines, if both cams are on one shaft I fear that the idea will be a non-starter (in both senses of the hyphenated word!).

DavidTappin wrote: I fear that the idea will be a non-starter (in both senses of the hyphenated word!).

After wasting another afternoon of my life surfing the Net till my eyes drop out I have come to the conclusion that at present this project is dead in the water. I'll hang it up back in the hangar again. The engine definitely needs a 16 inch or maybe 15 inch three blade pusher prop. I may nick all those new servos back out of it too.

Hi Phil,

What's the plane? Maybe I'm putting two and two together and coming up with 42 but could it possibly have a canard?

Chris001 wrote: could it possibly have a canard?

You could be right there and if it has it will probably sit in the roof archive till doomsday. And all for a prop. The 160s' that I have seen have got 3 blade props but maybe 15 x 3 x 7

I take it you've looked at the Master Air Screw range:
www.masterairscrew.com/collections/3-bla...propeller-rev-pusher

Sussex and Wheel Spin both sell the make, maybe they would be willing to add on the pusher in their next order?

I think I may have got it sorted. Back to Master Airscrew's page and have ordered 3 blade pushers, 2 x 16 inch props and a 15. Grand total $52.37 (£43.93) Free shipping via DHL. See what happens. I won't start fitting the engine till I have the props in my grubby mitts.