Page 20 - MFW June 2024

MILLS BOMB

Build Log

Nick Ward

Some of you keen model builders will immediately It had been well broken in, but had never flown. On a
recognise the following dilemma; a build project was whim, I clamped it to the bench and filled the 1 oz tank. It
started despite the existence of another major project (the fired up first time after priming and ran without missing a
3 year old DB Centurion) I had promised myself must be beat at half throttle for over 7 minutes until the tank ran dry.
finished before anything else was attempted. However,
several factors manifested themselves to prompt a spur- As the motor finally quit, I reflected on how
of-the-moment decision to embark on yet another ‘quick’ reliable/consistent the engine run was compared with the
build. Wasp’, and I distinctly remember thinking “Why the hell
haven’t I put this into a plane?”
Sound familiar?
I had allocated a precious ‘free’ afternoon for breaking-in This prompted, over the next 24 hours, the making of a
two ‘new-in-box’ motors on the bench. shortlist of available Outerzone plans for future potential
build candidates utilizing this little gem of a motor, keeping
The more important motor was the Centurion’s in mind I owned an unused ‘new-in-box’ OS15LA which
magnificent OS95fv, which had been sitting quietly on the would also eventually need a home.
shelf pleading to be at least bench mounted and tested for
4 years or more. This had been fitted with a heavy Master Having browsed through a list of David Boddington
Airscrew 16x6 ‘Classic’ prop. It started first time, and using designs, many suitable for the OS10LA, I noticed his Mills
the manual guidelines, three 12oz tankfuls of fuel were put Beam and Mills Bomb, the latter being for a 1.3cc diesel,
through, resulting in a total of 37+ minutes of initial break- which I equate to some extent with the performance of an
in. OS10LA. On reading the build notes, I suddenly had the
urge to immediately try to construct one of these quirky
The other was a little ASP .061 Wasp, with the idea I might looking (some might argue “downright ugly…”) beasts.
put it into a Simplex 40 in the future. The all-sheet Jedelsky wing and spruce warren-girder
fuselage meant a very quick build which wouldn’t really (I
I spent over an hour with the Wasp trying to get it to run convinced myself!) impede the finishing off of the
consistently, using two different glow head/plug Centurion.
combinations, but finally gave up. I couldn’t maintain a
steady run, despite following the manual instructions. By the end of the next 24 hours, I already had the full-size
Frustrated with only partial success, feeling disappointed plan, had bought a couple more mini servos, allocated the
with the Wasp’s performance, I noticed I had a 10 year old appropriate balsa from my ‘stash’ and had indeed
OS10LA lying in the workshop, already mounted for constructed the two wing panels. The Centurion would
bench running. have to wait just a little longer…

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