I promised to report on my progress with the
Ringmaster Biplane after it flew, and since it's
Ringmaster weekend, I'm going to indulge myself,
so here it is.
What this plane is, is two Sterling Jr. Ringmaster
wings attached to a S-1 Ringmaster fuselage and tail.
The bell crank position, L/G position and C.G. are
identical to the S-1. I'm sure I'm not the first person
ever to do this.
I've been pleasantly surprised that , so far, no one
has disputed it's provenance as a true Ringmaster.
Since Matt Kania designed all of the airframe except,
the struts, and wing mounts, I feel it's an honest and
true Ringmaster blend. Not for O/T though!
The good news and the bad news is that it flies
like a Ringmaster. No better and no worse. Several
people have flown it and everyone agrees that it's
a decent flier. Len Bourel completed the full pattern
with it on it's fifth flight (and his first) and that just
about says it all.
Everyone was happy with the LA.25 power but I
think it might be better with an LA.40. I think I can
feel the drag of the second wing. At 30.4 Oz and
400 sq/inch , it isn't heavy, but flying in yesterday's
strong winds, I feel I want more power overhead.
The engine is a LA.25 with a metal back plate and
venturi NVA. The stock OS muffler was included in
the balance calculations and works well.
I changed the prop up from a Master Airscrew 9-4
to a 10-6 and that works better.
The plastic clunk tank is mounted inboard and is on
muffler pressure.
The entire power system is pleasant and reliable.
The lines were 60' - 0.15
Several people seem interested in building a bipe,
so here's a few things that might help.
I used Adobe Illustrator's " Blend/steps/ expand"
function to generate the Jr. Ringmaster ribs. Then I
stuck the printout to the 1/16" balsa and hand cut them.
This is fast and accurate. If anyone wants to build a
Bipe or a Jr. Ringmaster, I can send them a PDF file
to print.
I always build up my profile fuselages but it isn't
necessary for this plane. The important thing is to
get the wing mounts aligned " Zero/Zero" to the
thrust line. This is easy but important.
The separation of the wings is dictated by sitting
the top wing on top of the S-1 wooden "canopy"
and the bottom wing on the bottom of the S-1
fuselage. If anyone is interested, I'll happily send
them a simple drawing of the struts and mounts.
The lead out guides are mounted to the struts and
needed to be adjust much farther forward than
I expected. The picture shows them in the
"too far aft" position.
So that's about it. This is a nice sport plane and
something different for Ringmaster events.
I think Matt Kania would be pleased.
Topic: Ringmaster Biplane flies! (Read 4643 times)