Gladys No 97 - Sheffield Society of Aeromodellers

ISSUE No.97
Spring Apl—Jun 2006
Photo by Mike Bowles
The Sheffield Society of Aeromodellers
page 1
The Newsletter of The Sheffield Society of Aeromodellers
Production
Editor :- Mike Bowles
5 Worcester Drive Sheffield Sl0 4JG
Tel:-0114 2304813
E-Mail: [email protected]
The Editorial Team:
Mike Stott - ace reporter and photographer
[email protected]
Terry Gregory - committee liaison, events and progress chaser
[email protected]
Jeremy Storr - proof reader
Colin Troise - distribution
[email protected]
Tel:-0114 2307584
Original items published in The Newsletter of the Sheffield Society of Aeromodellers may be
reproduced in club and society newsletters, providing that both the author and the newsletter
are credited.
It would be appreciated if a copy of the publication could be forwarded to the author of the
item (via the editor at the above address), so that he/she is aware of its use.
Permission must be obtained before using any item commercially.
The views and opinions expressed in any article printed in the Newsletter may not necessarily
reflect those of the editor, the committee or membership of the SSA.
The SSA, its Committee and membership do not accept responsibility for any advertisement
placed in the newsletter by individuals or commercial entities or for any safety (or any other)
advice published in the newsletter.
In other words - Use your common sense and don't blame us if it goes wrong!!
Subscriptions are available from the editor, at only £9:00 (UK) for six issues.
Cover picture: Terry Gregory returning with his Easy Pigeon after catching a “whale” of a
thermal
Rear cover: Gordon Smeeton celebrating his 75th birthday with a few flights at the Redmire’s Sports field with his tamed “Electroflight”
page 2
My Scottish Concourse
Have you tried a “Depron Pusher”?
Servo Mounting
The Saga of Mini-the-Mag
Psst! How about a cheap thrill?
Multiplex Mini-Mag
For Flyers and Camper
A Spitfire and “Mr. Grumpy”
Richard Whiting
Roger Lombard
Tim Scowcroft
Richard Whiting
Richard Whiting
Jeremy Storr
Gordon Smeeton
Gordon Smeeton
page 4
page 10
page 14
page 17
page 18
page 21
page 25
page 27
Editorial
Most of us love the sight of a Warbird, be it WWI or WWII, don’t we? Is it
the sound they make? Is it the shape? Or is it just the association with a time
when we were younger? On page 27 Gordon gives us a clue as to how he feels
about such aircraft. In the past month or so many of us have seen flypasts to
celebrate the Queen’s birthday, or been to air shows where Spitfires and their
1940s associates have thrilled us once again. At the Redmires field this week I
arrived just in time to see Martin Aspinall flying his excellent model. But I was
struck by the fact that it didn’t quite sound like the real thing I saw at Duxford
on the 9th July. Seeing more than a dozen lined up close to the flight line was
impressive, but hearing six Spitfires and six Hurricanes take off and buzz the
airfield several times somehow penetrates every sense that we possess. The
only sounds to top that were the four Merlins on a Lancaster and the super fast
Griffin powered Spitfire doing a low pass along the flight line. The most painful
part of our trip to Duxford was the long wait at the pay desk: the telephone
system was playing up but they still managed to extract £50 from our account.
But once inside the cost was soon forgotten. Well almost, they kept up a constant barrage of requests for further financial support for the excellent work
page 3
Photo by Mike Bowles
Seafire
that they do at the Imperial War Museum. Five pounds for a programme (I
wonder what it told those who bought
one?), four pounds for a walk down the
flight line, two for a sit in this plane,
four for a walk through that one. But
really it must have been worthwhile, I
even overheard Carol telling someone
how much she had enjoyed it, seeing
the aircraft and the flying of course!
If you haven’t been over to Cambridge
to see the museum it is well worth a
visit. The Flying Legends weekend in
July is however something a bit special.
Photo by Mike Bowles
page 4
Whilst we were away this past
weekend I was telling a relative
about the day and he kinda upset me—he had been given two
VIP tickets to the Waddington
airshow but he hadn’t been able
to use them because of another
commitment. Come to think
about it I couldn’t have gone ei-
ther.
In recent issues people have proposed
designing a club model and holding a
competition—where are the designs
guys? Which reminds me that I need to
thank those who do contribute to the
magazine. Thanks guys I really appreciate your efforts. If you are one of
those who maybe think that we are
getting too much from the same guys
then the solution may be in your own
hands, or heads. Don’t just sit there Do
something.
My Scottish Concourse
I must compliment my fellow members for what seems to have been a
marvellous concourse night at the
club this year. Needless-to-say, now
I’m living in Scotland I was unable to
attend, and therefore missed the
opportunity to show off the fruits of
my most prolific building season to
date, with no less than three new
models hot off the building-board. So
perhaps I can squeeze in a personal
postscript to the club night via
Gladys.
I am not a great model-maker so I
only buy ARTFs, but I do like what I
fly to be strong and safe. Flying objects are potentially dangerous, and
the idea of an expensive model hurtling through the sky out of control
fills me with dread. Which is why I
find myself getting extremely irritable with some manufacturers of
ARTF models. I get annoyed by incomprehensible and inaccurate instructions. I fume at inappropriate
components and design features
which are plainly going to cause trouble. And all three of my winter builds
have engendered irritations of this
kind.
My first effort was a GWS Formosa.
This model seems to have attracted a
popular following, and it must be hard
to find a better model for under
thirty quid. I am delighted with the
Richard Whiting
appearance and flying characteristics
of this model, but from a construction point of view it is not without its
faults. The first thing that struck
me when opening the box is that I
was not dealing with Multiplex quality. In fact every non-Multiplex
model I have bought reminds me just
how good Multiplex models really are.
The foam looked soft and low-density
and there was some minor warping of
the fuselage. It looked quite flimsy
and unlikely to survive even a modestly hard landing. However a carbonfibre spar is included, and once assembled the whole did seem tougher
than the constituent parts. However,
I was not at all happy with the aileron linkages, as they are simply
metal rods glued into the thin foam.
It was immediately apparent that the
movement of the rods would quickly
chovel out the foam inside the ailerons and cause catastrophic failure. In
my view a strengthening of all the
points where link rods are glued into
foam is vital. Another gripe was the
control rod adjustments, which rely
on V bends which are an utter pain to
make and adjust. On the rudder and
elevator links these were abandoned
in favour of adjustable control rod
connectors. Another pathetic design
element was the cockpit fastening
page 5
750 cells, and although these are
adequate, it does require full throttle to keep it airborne convincingly.
I’ve got 3 models using AAA batteries but I’ve concluded they are too
small for decent performance and
endurance. Personally I will not buy a
model that uses AAAs again, but the
fear of burning down a farmer’s crop
– or even worse, my house and garage, prevents me from considering
I painted the finished model in
WWII US Navy colours with a bright present LiPo technology as an acceptyellow cowl, and made some decals on able alternative yet.
the computer using white inkjet De- The Formosa flies beautifully, but it
nosed over a couple of times trying
cal Sheet from Overlander. (This
ROG take-offs on a rough football
works brilliantly, but the finished
decals do need painting with Humbrol pitch, and I subsequently found that
the thin plastic cowl had cracked
clear matt as otherwise the inkjet
image scrapes off quite quickly). The badly and had to be repaired with
tape.
power comes from 7 x AAA NiMh
which relied on a magnet. In my view
the cockpit cover is the last defence
against dropping a heavy battery if it
breaks loose from the Velcro, and
after all this is an aerobatic model. I
fixed this using a front tongue and
rear clip mechanism. The horrible
GWS wheels were replaced after the
first two flights with smaller and
nicer-looking foam-tyred wheels.
page 6
trim control. At least Depron is easy
to repair and strengthen, and it was
quickly ready for the air again. This
time it flew beautifully on the local
field and had done several circuits
when suddenly the wings clapped
hands and down it came again. This
time the repair was more like a partial rebuild, with new motor mount,
and wings reinforced with long bamboo kebab sticks and cross-weave
tape. And yesterday it had another
outing. Its best flight yet with
After three outings this model has a plenty of height and just a touch of
100% record. That is 3 flights, and 3 right trim. Until, after several gentle
crashes! The first came from faulty circuits the wings suddenly folded
yet again at the root. I think the
instructions which I was foolish
enough to trust. They said that 3/8” Mini-Max wingspan is just too large
for Depron so I am now planning to
down elevator was needed for
cannibalise the useful parts for a
straight and level flight. You can
home-design. I reckon I can’t do
imagine what happened. Its first
much worse than Wattage!
flight was a struggle to prevent it
Which brings me finally to my latest
from diving in, and it struck dirt
when I took my eyes off it for a split pride and joy – the RCM Pelikan Tukano which I won from RCM&E last
second to fumble for the elevator
After a hilarious visit to the first
SSA Indoor Session I decided that
an indoor model (and a crash helmet)
was a must-have. I bought a Wattage
Mini-Max from Tags for £25, but
never got around to building it until I
got my new hobby-room set up here
in Dumfries. It bears a passing resemblance to a WW1 monoplane, and
is largely constructed from Depron,
but it looked pretty and was stated
to be capable of flying indoors or
outdoors, even in a light wind.
page 7
year. This model got rave reviews,
which is why I again found myself
feeling niggled by confusing and occasionally contradictory instructions,
and by hardware which is either unsuitable or completely unusable! I do
wonder if magazine reviewers are too
afraid of not being sent any more
free models if they tell the whole
truth about the kits they review! To
be fair, this is a beautiful model, but
if you buy it, read the instructions
but then think it all through very
carefully, because there are some
real sequential pitfalls, as well as the
other problems mentioned here.
I found three main issues with this
page 8
model:- Firstly, it is said to be designed specifically for the AXI
2814/10 which I duly bought for it,
but in fact the motor mount holes do
not fit this motor at all. (Puffin recommends a Mega motor, which apparently does fit). Nor do RCM Pelikan
have a spinner/prop-adaptor to fit
the 4mm shaft on this motor. Airintake slots are adequate for cooling
but there is nowhere for the air to
escape, so I will have to make vent
holes in the fuselage to ensure
proper air-flow cooling of battery
and ESC.
My second gripe concerned the wing
servo trays. When the pre-cut
hatches were removed there were no
ply servo mounting plates, but you
were expected to “paint” the balsa
underside of the top surface of the
wing with epoxy and then use sticky
pads to fix the servos in place. If it
was ever necessary to remove a
servo, you would most likely end up
having to rebuild the wing! Also the
wing camber was such that the
mounting angle was wrong, and the
depth of the wing such that the arm
would not protrude adequately. The
only answer was to make ply servo
trays with a riser at the front and
epoxy them in. Not difficult, but on a
model of this price and quality this
should have been sorted out better.
The third problem area related to
the tail surface controls. The snakes
were already glued in, but unusually,
the rods did not cross in the fuselage, which meant that they would
have to be bent under considerable
tension at both ends in order to
function. Not good. I solved this at
the servo end by making a replacement ply servo tray allowing the R/E
servos to be positioned close together in the middle of the model,
but the problems at the tail end were
much more difficult to resolve. The
supplied control rods were not long
enough to reach the control horns
without soldering on the supplied
threaded adaptors. However, when
the supplied plastic clevises were
fitted, they extended beyond the
hinge line with the soldered adaptor
hard against the end of the plastic
tubing, and were therefore useless.
Also the supplied tail horns were tiny
little creatures unsuitable for lugging
such a large model through an aerobatic sequence. The fuselage is quite
thick near the bottom of the rudder,
so the commercial rudder horn I
used had to be cut away at the bottom in order to permit any right
movement at all. All-in-all the tailfeather control system as supplied
was a complete pig’s ear!
It’s now finished and looks gorgeous
but I haven’t flown it yet – I plan to
get in a lot more low-wing practice on
the Formosa first, and then wait for
a perfect day to fly this beauty for
the first time. Watch this space …
page 9
Have you tried a “Depron Pusher”?
Depron’s primary purpose is underfloor insulation. In its XPS form it is
a closed cell foam which represents
an excellent opportunity for aeromodellers. XPS stands for extruded
polystyrene (as opposed to EPS – expanded polystyrene – also used for
models but in moulded, not sheet
form). Because XPS is skinned and
closed cell, in most respects it has
the advantage over balsa in both
strength and weight, it’s easy to glue
(UHU POR is excellent), it’s easy to
cut and it’s resistant to impact (very
important to me!). It’s not easy to
get a decent (smooth and/or shiny)
finish but can be painted using water-based acrylics or felt marker
pens. Note: solvent glues will attack
it, so POR (not ordinary UHU), epoxy,
and foam friendly cyano are the
weapons of choice.
If you place great store by scale accuracy and realism in the detail this
article is not for you. If, on the
other hand, you’re happy with something that, at least in the air, looks
“right”, is cheap and quick to build
from a vast range of free* plans and
will give you one or more “jet” aircraft in your fleet, then read on.
If planes such as the F-14 Tomcat,
F-15 Eagle, F-18 Hornet, T-38 Talon,
Saab Gripen, BAe Hawk, EF Typhoon,
GR1 Tornado and MiG 29 include one
page 10
Roger Lombard
or more that interest you go to
http://www.parkjets.com/freeplans.html where you will find plans
for all of them, and many more. Especially look out for those by JETSET44 – a.k.a. Steve Shumate, who
produces planes that are regarded as
benchmarks for flight performance
but whose plans are easy to use as
well. Look for them in “tiled” PDF
format. They will then print out on
A4 thin card on your home printer.
You spend a happy hour taping the
tile jigsaw together and then cut out
your card patterns to mark out the
depron. If anyone has a system for
printing straight onto standard
sheets of Depron, I’m interested - as
will be several thousand others.
Most of the plans use 6mm Depron
and you will need occasional bits of
hardware such as CF rod and/or
tube.
If you’re daunted by the prospect of
“rolling your own” you can buy various
ready cut kits online from Steve
Webb (3D foamy imported from the
US) - http://www.servoshop.co.uk/
index.php?area=aircraft&make=3D%
20Foamy&title=3D+Foamy+Kits
or http://www.foamyjets.co.uk/
(who is BRC Hobbies supplier) to
name but two.
Power? Well, they will mostly fly
with a GWS type geared 350 but the
popular “bell” type outrunner with an
8040 or better still 8060 HD prop on
a 3 cell LiPo will make them come to
life and beyond that the choice is
yours, although something capable of
pushing out 200 watts ( such as
Tower Pro 2409-12 outrunner at
£24.99) is really as exotic as you’ll
need to get. A word of caution –
whilst a three cell Lipoly capable of
delivering around 15 amps will suit a
wide range of motors the fuselages
can be quite narrow so a long slim
battery such as the Flight Power
EVO20 3s1P 1200 is the sort to look
for – something around 35mm wide.
The cheapest I know of (black) works
out at £2.62 per 1250x800 sheet
plus shipping and VAT but you need
to buy 10 sheets to get that price
(which can make you 5-10 planes – an
opportunity for co-operative buying
perhaps?)
They have slightly unusual flying
characteristics – I mean we’re not
talking high lift aerofoils here –
we’re talking high power/weight ratio
flying planks which are capable of
flying very fast and very aerobatic
but also very slowly at high alpha angles so you bring them in and you can
virtually “harrier” them down vertically. You’ll see demonstrations of
this on the video links on the foamyjet website.
Some tips.
Watch out for being ripped off by
some shops on Depron pricing. 6mm
comes in two colours, white and grey
of which white gives you more options for colour through airbrushed
water based acrylic. For some reason black comes in 800x1250 tiles
whereas white is made 700x1250.
http://www.funflysupply.co.uk/ is a
source of a pack of five white
250x700 sheets for £5.99 – or if
you drive into Denton on the eastern
outskirts of Manchester - he will
sell you an uncut 1250x700 sheet for
the same price. A single pack will
normally be more than enough to
make you a plane.
As I’ve already said UHU POR is excellent glue for Depron.
If it makes you feel better sanding
rounded edges onto your flying surfaces do so but it doesn’t seem to
affect the flight performance.
Because the motor is at one end and
the battery at the other (most of
the models in the photos are around
40” long by 30” wingspan) then
there’s an issue about cable lengths.
The conventional wisdom is that the
cables between a brushless motor
and its speed controller should be
kept short but also that the cables
between the battery and the speed
controller should also be kept short.
Well, thanks a bunch for that really
helpful advice. In practice I haven’t
page 11
had a particular problem with having
the speed controller next to the motor so a long way from the battery
but these days I tend to compromise
by positioning the speed controller
on or around the CG which conveniently splits the difference.
flying skill than of any lack of benefit in having a rudder. Nor have I
(yet) built one with canards but both
the Gripen and the Typhoon do feature fully operational canards which
I imagine will help still further with
high alpha flying.
Most of mine use a “stickmount” arrangement but the plethora of new
outrunner motors and appropriate
mounts mean that you can simply
mount onto a ply bulkhead at the
rear. In practice I find it unnecessary to set either down- or sidethrust on pusher motors.
I use twin aileron servos with dubro
connectors and 1mm carbon fibre
pushrods – these are set so that
they can be adjusted from outside
the fuselage. Having learned the
hard way I now also rig the elevator/
stabilator servo the same way – so
that the trim can be adjusted without having to hack your way into the
interior.
Several, if not most, of the models
have full flying “stabilators” which
can make for a certain tightness of
the buttocks as you check out the
trim on the maiden flight. If it’s not
right shut the power off and the
“depron plane effect” comes into play
– the plane “harriers” more or less
level down to the ground. I don’t
bother with rudders but that’s much
more a statement about my (lack of)
Super Bandit (black)
page 12
Incidentally if you’ve read this far
without any particular interest in
adding a “jet” to your fleet there’s
also an excellent Steve Shumate plan
for a depron Fokker Triplane – see
the link below.
http://www.rcgroups.com/forums/
showthread.php?t=425387
MD (now Boeing) F-15 Eagle
MD (now Boeing) F-18 Super Hornet (grey)
MiG 29 (Desert camo)
page 13
Servo Mounting
Tim Scowcroft
simple CAD/CAM. “What is this?” I hear
you mutter. CAD/CAM is the ability to
design and manufacture using computers:
solid modelling techniques and machining
with numerically controlled machines.
You may or may not know that it can be
quite difficult to mount thin wing servos
within the confines of an aircraft wing.
The normal method with a moulded model
is to glue them in with epoxy or sometimes a hot glue gun. Both of these methods work: but in the case of the epoxy,
unless you cover the servo in tape or heat
shrink, the job is permanent. You may say
well that’s fine I will only remove the
servo if the model crashes and then it
may be a write-off or a major repair. In
the case of hot glue I have known it to
come loose or not be a good bond or even
soften in high summer temperatures.
(“What, with our summers?” I hear you
say.) [Ed. Here I am sweltering in 90 plus
degrees.]
On Sunday 4th of June I set to work.
Terry supplied a sample Hitec HS125
servo. I measured this and drew a suitable model. See below:
From this I was able to model a mount.
Quite a simple rectangular unit was all
that was needed, with recesses to locate
the servo mounting tabs and allow the
servo lead clearance.
Pete Cubitt sells a proprietary servo
mount and it was one of these that
prompted Terry Gregory to ask me if I
could make an equivalent or better.
As you may or may not know this year I
have become one of the great unwashed
and returned to education at Sheffield
Hallam University where I am studying to
become a Design and Technology teacher.
What you may not know is that this is no
longer just woodwork, metalwork and
A couple of cut-outs were placed at the
technical drawing. The world has moved
end to allow access to the arm mounting
on and we are now taught the black art of screw. Three mounting holes were added
page 14
to mount the unit onto a plate and positions were marked for the servo mounting screw holes. Hey presto! The design
was done.
At the university the 3D model file is
exported and converted into an STL file
(stereo lithography). This file is used to
run the computer controlled router. The
router, fitted with a 3 mm round nose
bit, took 15 minutes to produce a
“modelling foam” model.
Once two of these models had been produced they were sanded and separated
from the piece of base material. These
were then glued onto a piece of acrylic
sheet to form a pattern.
two part silicone resin poured in. 24
hours later we have a block of silicone
with the patterns enclosed.
The block of silicone was removed from
the casing and the patterns removed. We
now have the silicone mould or soft tool
from which the final servo mounts would
be made. Oh yes, by the way! This process is called rapid prototyping.
Around the edges of this sheet four
walls of acrylic sheet were raised and a
page 15
be removed and refitted as many times
as you like without the additional mess of
more epoxy and cleaning epoxy residue of
the servo every time it is removed.
The next step was to fill the inverted
mould with a mixture of micro balloons
and epoxy. This was a mix of about 30%
micro balloons by volume in 15 grams of
epoxy. Once this was set the moulding
was removed and the lower surface
sanded flat. You now have two HS 125
servo mounts.
The mould itself I have been told is good
for about 30 mouldings so I will be able
to make considerable use of this unit
over the coming years. If anybody out
there wants a pair of these servo mounts
I can be contacted on 07780 995441 or
0114 267 9467. My Email is
tim.scowcroft@ btinternet.com.
I knew giving up work would be of use to
me one day.
Once the mounting holes have been
drilled they can be fitted into any wing
that you take a 125 servo. The servos can
Photo and Poem by Richard Whiting
page 16
The Saga of Mini-the-Mag (Ode to a Multiplex Mini-Mag)
“You know you want one”, Jeremy said
And what he said was true
But that was just the half of it,
For Jeremy craved one too!
With ROGs an empty dream
It struggles just to fly
More dozy yet than docile
It lumbers round the sky
And on the sixteenth day of June
A Friday to be sure
Though they were many miles apart
Both went to a model store
“You’ve either got to beef it up
Or cover up that name”.
Carol spoke the truth of course,
It really was a shame.
The very same time, on the very same day
In Lancaster and Leeds
Each one purchased his heart’s desire
Plus other modelling needs
“But here’s the answer” then she said,
“I’ve got a brand new tag.
As you insist on fishy names
Just call it “Minnow-Mag”
Richard, set on a budget tight
For a Permax decided to settle
While power-mad Jeremy splashed out
On brushless heavy metal!
But Richard wouldn’t let it drop
He had another ploy
“I reckon that a different prop
Would liven up this toy”
The two then laboured mightily
With superglue and kicker
But Richard could not bring himself
To affix a German sticker
And so another Jiffy Bag
From Overlander came
With a 6x4 Electric Prop
An APC by name
So on the PC he contrived
New decals to design
With Overlander’s vinyl sheets
In colours more benign.
A smaller receiver was installed
To save an ounce of weight
Then increased aileron throws dialled in
Not just on Dual Rate
“And Mini-Mag’s a silly name”,
He said with great disdain,
“I need to have a better name
Emblazoned on my ‘plane.”
And what a difference this has made
A total transformation!
It whizzes now through loops and rolls
To cries of great elation.
“Piranha” I shall call it.
“That name will add some bite,”
But all of this was done before
The model’s maiden flight.
From a standard 7 x AA Pack
Twelve minutes plus is wrought
And banished all the doubts and fears
Of what on earth he’d bought
The Permax couldn’t do the job
Performance was so tame
It quickly was apparent
That it didn’t match its name!
So Minnow-Mag’s got back its teeth
Performance with some bite
And it keeps its name “Piranha”
To Richard’s great delight.
page 17
Psst! How about a cheap thrill?
No, I mean it! If you fellow aeromodellers really want a cheap thrill, get a
GWS F3A Formosa.
You can buy the F3A Formosa for less
than thirty quid from most model
shops and when you consider this includes the motor, gearbox, prop and
spinner it really is incredible value.
What’s more, it only needs three micro
servos for full E/A/R control – there’s
another saving! Even better, it flies
exceptionally well for 4-5 minutes at
full throttle on a 7xAAA 750MAh battery – and as AAAs are the cheapest
rechargeable cells you can buy, you can
make up your own flight packs as cheap
as chips. If you’ve never made up a
battery pack, it’s dead easy – I’m sure
Terry Gregory would be happy to give
you some tips, as he did for me when I
got started.
Richard Whiting
It is not surprising GWS have labelled
this the F3A Formosa because this
baby is fully aerobatic, even in its basic
form. Inverted flight, multiple rolls,
bunts (outside loops) – both down-
wards, and upwards from inverted, vertical figure-eights – all the most contorted multiple patterns are achievable.
And a whole industry seems to have
sprung up around this model, with everybody and his dog offering brushless
upgrades for it. Overlander can offer
The instructions say that this model is about three different options from
inrunner/gearbox combinations with
for advanced or expert pilots, but I
had flown nothing more demanding than aluminium motor mount, to HET direct
a TwinStar before flying the Formosa. drive outrunner. Bell motor and ESC
combinations can be had for less than
Still I must say that the first few
£25. I can only imagine that the perflights were bum-clenchingly exciting
to say the least, and I found I needed formance with these power-trains must
be ballistic, but be sure to use
a few minutes to calm down between
stronger control surface hinges if you
flights! It’s not that it is incredibly
fast, but it is highly manoeuvrable – to go this route. With a brushless motor,
the extent of being quite twitchy, even I’d expect it to be possible to propwith 50% dual rates and 40% exponen- hang and do vertical climbing rolls, but
of course your thrills no longer come so
tial on the ailerons! It is perfectly
cheap! You may need to consider Li-Po
stable enough to easily hand-launch
yourself, but as soon as you start twid- batteries too, if you want to add
power, so it could start to get quite a
dling the sticks, things happen fast!
page 18
ramming everything into the foam firewall. It shortened the model by about
four inches, but the airframe and control surfaces were undamaged. So I
got a new prop, cowl and motor-mount
from Hillcott Electronics – all for unBut the best thing is, you don’t need to der eleven quid including postage, and
spend any more. You can enjoy throw- with the addition of a new ply firewall
she’s as good as new and flying beautiing this thing around the sky for peafully.
nuts if you just stick with the basic
version as it comes, and you can always There are some tips I can share with
upgrade it later if you win the lottery! you. The cowling is very flimsy indeed,
but costs £6 if you need to replace it,
I’ve got some much more expensive
models, but this has definitely been my so it is worth using cross-weave tape
inside it to add some extra strength. I
firm favourite all year.
damaged mine on the second flight
It is cheap and easy to repair too. I
ran into turbulent air in the lee of a hill when it nosed over trying an ROG takeoff from a football field. But I
on finals recently and the resulting
nose-dive from about twenty feet com- mended it with diamond tape and it
lasted until the big crash mentioned
pletely flattened the nose – breaking
above.
the motor-mount and prop, crushing
lot more expensive. The Formosa has
been such a phenomenal success for
GWS that they have even brought out
a Formosa Mk 2, which is bigger than
the Mk 1, but is more expensive and
does not come with a power system.
the cowling beyond recognition and
Having now tried the model both with
page 19
and without the supplied undercarriage, and even with some alternative
wheels, I would recommend dispensing
with the undercart completely, and
going for hand-launches, but do be sure
to strengthen the bottom of the cowling as mentioned above. I mainly fly
from a meadow with long grass, so soft
landings are usually not a problem for
me. And as it can cope with quite a
strong wind, it can land very sweetly
and softly with a bit of headwind to
slow the ground-speed. I had five
great flights this very morning in a
10mph measured windspeed and it
landed almost vertically as soft as thistledown.
Be sure to paint the model to make the
top and bottom completely different
colours. This model is so aerobatic
that even with a high-contrast paint
scheme like this, you can
easily lose orientation for a
moment or two. I abandoned the supplied decals
for a WW2 US navy scheme
to provide this high contrast.
Use stronger control surface hinges than the ones
supplied, and ensure the
metal link-rods are very
firmly glued into the foam
ailerons and elevators. (The
bends in the linkages may
need some alteration to
make them a precise 90 degree angle too). The ailer-
page 20
ons don’t need differential however, so
it can be flown with quite basic TX kit.
The cockpit cover is foam and as light
as a feather. (Experience says don’t
leave it anywhere near the prop when
you bench-test the model!) Don’t rely
on the supplied magnetic cockpit-catch
system though. I made my own which
has all the aesthetic and practical sophistication of a bent paper-clip, but it
keeps the cover firmly on.
Make sure your ESC can cope with the
amperage – I’d recommend a 15-20amp
ESC for some safety margin. I use the
supplied 9x7 propeller and it pulls over
10amps at full throttle.
I can’t think of any model which gives
so much “bang” for so few bucks!
Every aeromodeller should have one!
Aerobatic thrills really don’t come
much cheaper!
Multiplex Mini-Mag
Jeremy Storr
Photo by Mike Bowles
It was the advert that got me. It
didn't actually say, "Ve haf vays...",
but the words were almost as sinister, and persuasive: "You know you
want one", and I knew I did. What's
more, it promised, "No workship
required", which was just as well, as
workship is taking aeromodelling a
bit too far.
Of course, the connoisseurs among
us tend to think of foamies as junk
models, just as gourmets think of
Big Macs as junk food. I admit Multiplex have given the Mini-Mag a
McDonald's colour scheme, topped
with a liberal garnish of red and yellow Ms, but this is no junk model. It
offers a useful solution to a problem
faced by all aeromodellers in the
early stages - the transition from
rudder/elevator to full-house controls.
I was tempted by the Mini-Mag because I have had so much pleasure
and use from my Multiplex Pico Cub
over four years and the Mini-Mag
offered ailerons, a slightly more
compact airframe in tough Elapor,
and a brushless option powered by
the Permax BLX22-18 for a lively
performance. I wanted a model that
would be realistic in appearance, relaxing to fly, but with some aerobatic capability. The Mini-Mag, as
its name suggests, is a smaller, taildragging version of the tricycle undercarriaged Magister. It has just
enough dihedral to fly well on rudder and elevator, but can be converted easily to ailerons at any
stage. It ought to be an excellent
confidence builder for modellers
taking early steps in electric flight
and wishing to progress. As with the
page 21
Photo by Mike Bowles
Cub, floats are available, which require a special rudder assembly. The
motor supplied is a Permax 400 6v
with Gunther prop. A 3:1 gearbox
can be used, as with the Easy Glider.
brushed motor, and is sold with the
Multicont BL-17 speed controller
(which appears to be made by Castle Creations), a prop adapter and
an APC slowfly 8x3.8 prop.
I bought the kit from Leeds Model
Shop for £42.50. Although I
asked for the BL-X22-18 motor I
was persuaded that the instructions specified the slower revving
BL-X22-13. It was not until I got
home that I spotted the tiny misprint slip on the front cover which
corrected this to the '18' motor
(i.e. 1800 RPM/V). The Leeds shop
was happy to exchange the motor,
but why couldn't Multiplex stick
the misprint slip over the misprint
itself?
I decided to equip the model with
four HS55 servos. Only two are
needed for rudder and elevator, in
which case the ailerons are left uncut. I used one of the new style GWS
8 channel receivers - a bit bulky, but
full range and cheap.
The tiny, thimble-like outrunner
weighs half as much as the Permax
page 22
The neat box contains a one piece
wing, tailplane, fin, two fuselage
shells and canopy. Bags contain all
necessary hardware and wheels,
although my kit was missing the
grub screws, nuts and washers for
the pushrod connectors, which the
Leeds shop kindly supplied.
Construction is very straightforward, using slow cyano and activator almost exclusively. First the
snakes are installed in the fuselage
shells, which are then joined. A robust undercarriage mount is installed, followed by the plastic Permax motor mount. I adapted this to
suit the brushless motor by drilling
six 3mm holes in the front face for
cooling, widening the bolt holes, and
strengthening its attachment to
the fuselage with two 1/8" ply
strips extending behind the mount.
The rear ends of these strips act
as a stop for the battery which
would otherwise collide with the
motor in a crash. I put two extra
screws through the front mount
face into the front ends of the
strips.
Canopy clips and lugs, and horns are
then installed. The wing, retained
by a single bolt, is strengthened
with white carbon spar tubes glued
into a joiner. HS55 servos do not
have long enough leads to project
beyond the wing root for connection to the receiver, so I chopped
the excess off the rudder servo
and grafted it on to one aileron lead
with solder (staggering the three
wires to avoid short circuits). The
other I extended using a length of
lead from an old defunct servo.
A GP1100 8 cell battery, in two
sticks side by side, fitted perfectly
and brought the CG to the exact
position. The ESC lies above the
battery in my set-up, to protect it
in a crash.
The trickiest job was adding the
McDonalds stickers which provide
colour and visibility. You can work
up quite an appetite flying the MiniMag.
Flying
The instructions say the model is
designed for hand launching. In
Photo by Mike Bowles
page 23
fact, with the brushless motor, it
takes off perfectly from the
ground and climbs out briskly. The
Permax motor mount seems to lie in
the fuselage aperture at an angle
which reduces the downthrust
slightly, and there is a tendency for
the model to rear up somewhat under full power, but this can be corrected by mixing in a little downelevator with the throttle.
On the first flight, in a 5 - 8 mph
wind. the performance ranged from
docile to lively, depending on the
throttle, with no fraught moments
apart from when the prop flew off
under full power during a loop. The
model settled down into a long and
easily manageable glide and very
gentle touch down. On the second
flight the motor worked loose, so I
used lock thread on the bolts. Rolls
were rather slow and barrelly, so I
increased the aileron throws
slightly above those recommended.
The Mini-Mag flew for twenty minutes on one charge.
As yet I haven't really put the
model through its paces because I
am a little concerned about the motor. It seems rather noisy at low
revs and it locked up completely on
the third flight. I had to ditch the
model in the rough on the edge of
the field. When I flicked the prop
over there was a loud snap which
page 24
freed it and it ran properly again.
There was no apparent damage inside the motor so for the next few
flights I will take it steady and see
if this problem recurs.* If not I
predict this model will bring me
many hours of enjoyment, like the
Pico Cub. It represents excellent
value, in the Multiplex tradition.
By the way, here's a strange coincidence. I learned that Richard
Whiting, who, wooed by the advert,
has lusted after a Mini-Mag as long
as I have, bought one in Lancaster
on the same day, at the same hour,
as I did in Leeds, completely without collusion. I wondered if we
would get them mixed up next April
when we fly together in the Lake
District. But Richard’s superb customised décor in blue will prevent
that. (See page 16)
Specification:
Wingspan
1010mm
Fuselage length overall 820mm
All-up weight min.
580g
Wing loading min.
26g/dm2
Power system min.
Permax 400 6v
RC functions: Elevator, rudder,
throttle; optional ailerons.
*Postscript: further flights showed
no problem, giving good rolls and
inverted flight.
For Flyers and Campers
Gordon Smeeton
Photo by Gordon Smeeton
Bo Peep Farm Caravan Park: If you
fancy a bit of model flying at the
same time that you are caravanning
or camping then this is a site for you.
Bo Peep Farm is situated on the
B4100 off the A4260 just a few
miles South of Banbury. The site is
part of an 83 acre arable farm where
12 acres are dedicated to caravans
and tents. It is a very attractive site
situated well away from any roads
and housing. It has an excellent toilet block with all of the usual amenities. There are very nice walks within
the site and some interesting places
to visit: all quite easy to get to.
The attraction for model flyers is
that there is an adjacent field of
about 15 to 20 acres on which we are
welcome to fly. The field slopes down
to the South and the recommended
launching point is well away from
trees and other obstructions.
The site owner, Andy, is himself a
keen flyer but his plane is a twin engined Cessna.
The other interesting thing is that a
regular visitor to the site is Noel
Cross. He is so keen on model flying
that it is also his business: Noel has
been model flying since the age of
six. He now concentrates on helicopters and giving lessons on flying
model helicopters. He is engaged at
the present time test flying a pair of
IC helicopters for a well known manufacturer.
One perfect evening I was there he
gave me a demo of one of his indoor
helicopters and an indoor aeroplane
both flying on Li-poly batteries.
page 25
Photos by Gordon Smeeton
His company is called “Skids N Skills”
and his business card says he provides flying lessons, setups, repairs
and building services. If you are interested his telephone numbers are Bo Peep Farm can be contacted on
01295 810605
01295 264072 and Mob 07790
878635
page 26
A Spitfire and “Mr. Grumpy”
Gordon Smeeton
The excellent attention to detail on this model is shown here in the cockpit
I have got to that stage in life where
one tries to forget birthdays: they
seem to come around much quicker
every year.
But it is sometimes useful to celebrate
especially when you have sons who share
the same interests: in this particular
case - aeroplanes.
For my latest birthday my sons presented
me with a 1: 32 scale Spitfire made by
Corgi. Detailing is very good and all the
bits that should move do: the wheels
retract etc..
The Spitfire in question is a Mark 1A.
It was flown by Wing Commander
George Unwin DFM and DSO. He
flew right at the beginning of
the war and is attributed as
being the 14th most successful
pilot.
On one occasion during the Battle
of Britain he was shot up and had
to make a crash landing. He had
climbed out of the cockpit getting ready to jump but he
changed his mind and climbed in
again and landed safely: he was
able to fix the problem, climb
back in and fly safely back to base.
But why is he known as Grumpy? Douglas Bader was one of his fellow comrades and one night Bader had kept
George awake as he filed away on one
of his false legs. George Unwin complained and was told by Bader not to be
so grumpy: the nickname stuck.
The Corgi model has been created to
commemorate Grumpy's flying skills and
comes complete with a model of Grumpy,
two ground crew and Grumpy's Alsatian
dog: the dog was shot by a drunken commanding officer who did not like to hear
the dog barking.
page 27
Photo by Mike Bowles
page 28