Gyro pre-rotator question
W Ryan H
I see one of the things irritating to most ultralight gyro owners is the lack
of a pre-rotator, and how one would throw over the weight limit for FAR 103.
As I was mowing the grass the other day it dawned on me that the manual
mechanism used to start my mower might make a nifty little pre-rotator. Yeah,
it may take some arm strength and a couple of patient minutes to pull the cord
a few times but wouldn't something like that work ? Just curious if anyone has
every tried it.
Ryan Hulslander
Gyroplanes
It's been done. Credit Rufus Howard (formerly of Northern Illinois) for
building it first. It worked good, not good for a lot of RPMs though and nearly
as expensive to produce as a Wunderlich unit.
Tom
BH206B
I hate to bring this up, but I remember at OSH '95, Scott Malone was sitting in
his "ultralight" Soma (which most people assumed was a tad heavier than 253
pounds) in a line of gyros waiting to take off. As the line began to go, Scott
stood up, gave his rotor a shove to get it going, sat down, hit the throttle
(after buckling in) and took off in less room than the big, powerful gyros with
the prerotaters. I was impressed, and that's pretty hard to do.
Also, Jim Vanek's (Vancraft) father had a neat idea a long time ago, to use a
crank/chain affair as a prerotater. The crank was mounted low on the mast,
right behind the pilot. When you were ready to go, you simply reached back and
"cranked her up." I guess it would work pretty good for us single guys with
strong right arms ;-)
W Ryan H
Please forgive my stupidity, but what exactly is a 'Wunderlich' unit. Is that
the actual name for the little device we all have mounted about our lawnmowers?
Also, I guess I never really measured the amount of RPM's one of those babies
crank when I'm flailing away trying to start my beast to mow the grass. You
might be right.
Ryan
W Ryan H
>Date: 10/18/98 5:55 AM Central Daylight Time
>Message-id: <19981018065558...@ng83.aol.com>
<snip>
>Also, Jim Vanek's (Vancraft) father had a neat idea a long time ago, to use a
>crank/chain affair as a prerotater. The crank was mounted low on the mast,
>right behind the pilot. When you were ready to go, you simply reached back
>and
>"cranked her up." I guess it would work pretty good for us single guys with
>strong right arms ;-)
I saw that little doo-hickey in the early videos, before Vortex got em. I
thought that was pretty neat too. Someone e-mailed me another interesting idea
of using the gear shifter/derailleur <sp?> combo from a bicycle. It has the
sprague clutch needed to do the job and while you crank, you can change the
gears so you get the most speed for the pull.
Hmmmm.... Some really interesting ideas....
Anybody know if the 'hand-crank' pre-rotator is still sold for the
sport-copters or the plans to build one ? I'm curious as to how the whole
mechanism went together.
Ryan
Phil Williamson
W Ryan H wrote:
Ryan,
What do you mean by "before Vortex got 'em?" I've seen many Sportcopter
gyros (I live very close to Vanek's shop) and none so far have the manual
pre-rotor. If fact, the only model out there with that old (but pretty slick)
system is Chuck's old orange VW powered Vancraft gyro.
Also the last time I was out there I notice they FINALLY had the tandem rig
flying. I only had to wait 9 years but It's up in the air and being used for
training. Rod Scamahorn was doing the training (which keeps me away....this man
has an ego that's hard to believe. He's a damn good pilot and he'll tell you so).
Phil
W Ryan H
>
> What do you mean by "before Vortex got 'em?" I've seen many Sportcopter
>gyros (I live very close to Vanek's shop) and none so far have the manual
>pre-rotor. If fact, the only model out
Well, I've been looking at a Vancraft video that showed the single seat
sportcopter with the white enclosure that had the hand-cranked pre-rotator. It
also had footage of the hydraulic one as well. When I went on the internet to
search for Vancraft it was called Vortex, not Vancraft. I figured the company
was bought by Vortex. Was I mistaken ?
Ryan
Phil Williamson
W Ryan H wrote:
I guess I'm just being picky but...:-) There is no such thing as a Vancraft
Sportcopter. Vancraft was the name of the company when Jim's Dad (Chuck Vanek)
ran the company. They had a model called the "Lightning" that was produced under
the Vancraft name. It had the hand crank pre-rotor.When Chuck retired, Jim took
over the business and renamed it to 'Sportcopter'. His first machine under the
Sportcopter name was the 'Vortex' which was the result of several years of protype
flying. This is the gyro that he has (many,many times) looped. He then released an
ultralight (also with the name 'Lighting) that was based on the Vortex machine but
without all the goodies that Jim packages with the Vortex. Several months ago he
started flying his tandem gyro. He also has a side-by-side version of the Vortex
he was working on the last time I was out there.
Jim's attention to detail is second to nobody I know. He was very picky about
how the machine was when it was released. It was behind schedule but like a fine
wine, he would not release it before it's time.
The real confusing part is that both the Vancraft *and* the Sportcopter gyro's
use (more or less) the same body. If you weren't really up-to-date on the Vanek
story you might get them all mixed up.
None of the Vancraft models are available ('cept use). If you saw a Vancraft
video, you were looking at a fairly old tape.
Ship me e-mail if you'd like any more info.
Phil
Gyroplanes
Wunderlich has been producing them for about 25 years now and they can be found
on most gyros all over the world.
Tom
Dennis McGuire
This method is already being used successfully on the Gyrobee.
On Thu, 22 Oct 1998, Jasoncat wrote:
> Try using two model aircraft engines mounted on the hub section of the rotor.
> Start the engines as you taxi out, and even if you have to wait for a while before
> takeoff, your rotor keeps spinning. Simple! Because the engines are mounted near
> the centre of the rotor, they would have minimal effect on performance and would
> weigh next to nothing too.
>
Jasoncat
Start the engines as you taxi out, and even if you have to wait for a while before
takeoff, your rotor keeps spinning. Simple! Because the engines are mounted near
the centre of the rotor, they would have minimal effect on performance and would
weigh next to nothing too.
Jasoncat
