> > 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
The Dragonfly/Quickie/QII can handle an O-200 (100HP).
A one-rotor built on the 13B is 100HP, and weighs less.
Atkins has a one-rotor E-shaft available.
Keith
Keith,
The Atkins e-shaft is cast and is therefore unsuitable for aviation use.
Cast materials always have porosity problems - lower density ( lower
strength) with the possibility of casting voids, even a small blemish within
the material can cause stress risers and intimate failure.
The one rotor with cast iron housings will be about 240 lbs and about 80 to
100 hp, P-port will be closer to 115 to 125 hp, with a higher compression
rotor ( RX8) maybe more. The composite al and iron housings ( being
developed by Richard Sohn) may save you a few lbs. The outrageously priced
aluminium housings will save more.
I forget what the 0-200 weighs.
The price of the ( quality) single e-shaft is the stumbling block at this
point in time - something I'm still working on, however I firmly believe
that there is an area of high demand for this weight and HP class.
George ( down under)
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