On May 21, 10:21*am, wrote:

One quick question, will a motorcycle chain system work for a prop?

Hey Canuck,

Where-the-hell you been for the last 106 years? Take a look at a few
old photos and you'll see the answer to your question. Now before
everyone assumes that they know where I'm going with this response,
let me dispell a few myths:

1. it was NOT a bike chain. It was a #35 solid-link chain made by
Diamond. Two props means only 5.75hp per prop, so the #35 was the
correct size for our two brothers from Ohio (same size would work well
on a go-cart).

2. The two biker-brothers from OH were NOT the only ones to use a
chain PSRU successfully. Ben Epps did it in 1907. And some Italian did
it in the teens. Never did identify that plane, but it was a flying-
boat with a high-mounted chain-driven prop.

3 Tortional (sp??) vibration would be a serious issue if you don't
know about the working solution for it. That being a prop-shaft made
of spring-steel. Think tortion-bar suspension. Wil and Orv discovered
this the hard way by cracking two sets of tubular prop-shafts before
treking back home and making a suitable replacement. (Oh yea, don't
forget to squirt a little "Arnstein's tire cement" on the threads of
your shaft nuts or they'll come loose.)

Now would a modern motorcycle chain work? You bet. Would it be really
heavy? You bet. Could you find a suitable airframe that would handle
the weight, deal with the vibes, and last a reasonable amount of time?
Hmmmm. One thing is certain about chains though. They typically draw
1-3% of the engine's power. A belt is usually 5-15%. That's why you
don't see too many belt-driven bicycles out there.

If it were me, I'd be inclined to try two B&S Vanguards driving
outrigger-props via chains or serpentine belts on a test-bench just to
see what I could get. Probably a waste of time, but we are here to
experiment. Too bad all of the small I/C diesels are rediculiously
expensive and super-heavy.

Hey Euro-pilots, got any small diesels that might work with direct-
drive? No dice here in the States. Diesel here equals truck.

Harry