On May 22, 10:17*am, wrote:
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

Geschwender used the Morris Hy-Vo chain in his redrives, and they
worked well. That chain has teeth that engage sprockets that look like
gears instead of sprockets, and as the chain curves onto the sprocket
the teeth spread and get tight between the sprocket teeth so there's
no slop.
See http://www.alternate-airpower.com/
and http://www.fairmont-mn.com/altpower/psru.html

Dan