> > I am 90% done with the airframe of my dragon fly I
>
> am intending to
>
> > power it
> > with a 13b. Any comments? Anyone seen a rotary
>
> powered dragonfly?
>
> > would make
> > quite a buzzz.....
> > --
> > Thanks,
> > Brent Hasty
> >
> > Isn't it a bit heavy Brent?
> >
> > Paul Lamar
--------------------------------------------------
vw engines are around 165 lb average see:
http://www.greatplainsas.com/specsfd.html
I initially began to think about repowering with a rotary when on the list
someone sent out a link to an outfit making alumininum side plates, this
makes it around just 50lbs heavier than a vw for well over twice the hp,
not
to mention reliability issues...
What are other means to put a 13b on a diet, if one were willing to
sacrifice
a little bit of horse power?
I do not think a rotary powered dragonfly is insurmountable.
------------------------------------------------
> I'd think so.. I just about bought a Dragonfly
> project, but was
> discouraged by the weight limit for an engine, and
> who wants to
> fly behind a VW motor?.. If memory serves me
> correct, a c-85 was
> to much weight. A single rotor would fit, but that
> might mean a
> bit of a wait until they get on the market..
>
> Jarrett
--------------------------------------------------------------
What are the dynamics of aircraft performance that are affected by a
engine
weight increase like I am discussing?
Consider the reduction of stall by modifying the Aelerons with a flaperon
mechanism similar to the kitfox and avid?
---------------------------------------------------------------
I owned and flew a Dragonfly for many years. The 13B
is too heavy and powerful for that design.
-------------------------------------------
How can one ever have too much power?
-----------------------------------------
It was
designed around a 1600cc vw, but others have installed
c-85/O-200, Jabiru, Subaru, etc, up to about 135hp.
Mine was powered by the humble VW for 240 hrs or so,
then switched over to a turbocharged Subaru EA81.
Performance increased significantly, and no more 50 hr
valve jobs req'd.
-------------------------------------------------------------
At 200lbs the weight of a 13b-aluminum is equal to the ea81 with
significantly
more power.
Any clue the VNE of the dragonfly airframe? (cant find it on google)
------------------------------------------------------------
There was one fellow out near Mojave somewhere that
had built a single-rotor powerplant for the DF. I
visited his hangar back in the mid-90's. I have no
idea if it ever flew with that engine.
-------------------------------------------------------------
I have a farm I bought to put a fabricaton shop on that is 2500 feet long,
I
hope to be able to get in and out with the dragonfly.
The extra power will help to leap off the ground, but I will have to deal
with
a hot landing...... Again the flaperon idea may help.
Thanks,
Brent Hasty
Be careful with flapperons. If not done properly you end up with almost
enough flap and not enough aileron control just before touchdown. Is the
Dragon Fly really a rough field bird? If you have to go rotary, then a
single rotor seems the way to go. How were you planning to plumb the
radiator? Midships with an intake?
best
George W
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