Page 16 - MFW Dec 2024

parts with recessed bolt heads and captive nuts to More (and more!) testing…
connect all the carbon tubes to the aluminium parts. I made a pair of longer blades. I was getting better at this
Unfortunately the bolt heads were bigger than the ones I’d and they were another improvement on the previous set.
measured and they split the fittings as I screwed them in. I Fast taxiing runs showed the blades might be up to the job
also found everything very difficult to assemble – in and then it was a matter of gathering my nerve to give it full
addition to the frustrations of working with tiny 2mm bolts throttle. Although it’s less obvious on a gyro fitted with a
and nuts! A redesign was in order but the original looked modern, high-powered pre-rotator, take-off is the hardest
okay and was strong enough to withstand the trials so the part of gyro flying because the machine can’t be flown
rebuild was scheduled for after the test flights. safely until the blades are flying. Forcing it into the air is
likely to induce blade flap with potentially catastrophic
A name… results, so it’s a matter of travelling fast enough to induce
When it came to a name I remembered Victor Borge, the autorotation and gradually stepping up ground speed until
Danish musical comedian who did a skit on “inflationary the blades are up to flying revs. With a miniature that
language”. As my version was an augmentation of the couldn’t provide any of the tactile input experienced by the
original Dominator I decided that DomiNiner would do pilot of a full-sized machine, judging when that might be
nicely! Meanwhile the pilot acquired a version of my name, was always going to involve some experimentation! Dave
though people reckon he looks a lot younger than me . . . captured the vital run on video. I had used up a lot of
runway when I finally
g a v e i t i t s h e a d ,
whereupon it leapt off
the ground and in a split
second did a flip half a
metre off the ground,
d e s t r o y i n g t h e
blades in the inverted
l a n d i n g ! D a v e ’s
comment at the
end of the video
s u m m e d i t u p
beautifully – “Well
at least it got off the
ground Jim!”. We
had a bloody
good laugh and I
headed home to
make another
set of blades.

DomiNiner in original configuration ready for first trials
Testing times
By now I was getting nervous. When you build a plane Back tracking to start maiden trial run.
from a set of plans or a kit you have a reasonable (Mount Edgecumbe in the background)
expectation it will fly. Doing it from scratch adds more
uncertainty and I decided to maiden it (or not!) privately at While I was about it I designed some more meat into a
the flying strip before showing it off to the rest of the guys. A couple of the printed parts and rebuilt the engine mount
suitable day finally arrived and flying mate Dave took a few area as planned.
pictures for posterity. I started by seeing how the blades
auto-rotated as I taxied up and down the runway while I Trial 3
got used to the controls. We reduced the steering ratio on The pre-rotation method proved to be a problem as I had
the front wheel and did a few other adjustments, then the to stand behind the machine to do it. I needed to flatten the
pre-rotator was employed. It soon became apparent that rotor as the front wheel lifted to get the gyro to balance on
the rotor disc area was insufficient to get the gyro off the the main wheels, then apply power until it lifted off but I
ground. So much for the calculations: I wish I’d stuck with was unable to see what was happening. In typical model-
my gut feeling and made the blades longer! I wasn’t too flying fashion everything happened faster than I could
upset as I’d had a ball finally being able to play with it after react on the controls and the result was inevitable. It was
all the months of effort. time for the long-term solution.
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