MODEL RADIO CONTROL ELECTRONICS 
Another continuation page of the norcim website
covering some model aircraft design and a detailed description of a UHF radio
control system for use on the model control band. Some retro historical radio
systems are also expected to be covered on this page too. You will
also find some related Gooooogle advertising on this page so why not suss out
the suppliers of Model Radio Control Electronics.....There's also a web search
tool at the bottom of this page where you can use this site as a spring-board
to other similar sites....simply add a keyword(s) of the item you wish to find!
We hope you enjoy and please do come back to us soon........The Norcim Team.
DETAILS
OF SOME INTERESTING MODEL AIRCRAFT DESIGN
IS IT A HORTEN OR NOT A HORTEN?.......Nicholas Ingle and his
extraordinary flying machine
Well....to be
entirely honest it just looks just like a Horten flying wing but in actual fact
this gigantic model is based on the Northrop N-9MB which was a 1/3 scale
aircraft used as a proof of concept machine for the XB-35 and XB-49 bombers.
Span is 102 ins.
Major chord 17.25 ins with a minor chord of 7 ins. Section is Eppler 334. There
is a progressive washout starting at the root where it is zero and finishing at
the tip where it is 6 degrees. Control is by elevons.
The model is
configured so that a plug in electric power pod can be fitted. The pod uses an
AXI 2820/12 brushless motor and a 10 cell battery pack from Puffin
Models. It fits onto the centre trailing edge of the wing pushing the machine
forwards.
The model is now
covered and ready to fly. Some research work has been going on however, before
flight testing, to come up with some form of differential drag flaps at the
tips of each wing to help give a ‘Rudder Effect’ when ailerons are used. (note that there aint any rudder on this
machine!....). Although these drag flaps were first planned as a mechanical
linkage, Nicholas is now using an
electronic on-board mixer which gives more control over the drag effect
required.
Nicholas mentions
the fact that the trick in building the wing came from a web site called
THEGOODPAGE...I aint looked there yet but will do so soon. Perhaps
it could be found using the search tool at the bottom of this page?
Nicholas also sent
in a picture of his completed and test flown power assisted glider. In these
days of models 'off the shelf', it's refreshing to see that there are still
some modellers that are designing, building and even test flying models from
scratch. Without these talented people there would simply be no 'off the peg'
packaged products for us to buy! Good on ya Nicholas!!
Span is definitely
not in the 'toy category' at a big 115 inches! This is certainly a man-size
machine that will obviously not only impress the neighbours but will also cause
lots of interest down at the flying field. The propulsion unit for the model is
the AXI 2820/10 motor with the Jeti Advance controller from Puffin Models.
Other info includes a Maximum chord of 10 ins with a Tip chord of 7 ins. The
wing is built in two halves. The central flat part is 30 ins long and the tips
are 21 ins. The extra few inches comes from the fact that three laminations of
1/4 balsa are used on each wing tip. Wing section is the well used Clark Y. The
whole of the 'T- Tail' is removable to facilitate safe transit to the flying
site! Wing loading works out at 11.35 oz/sq.ft. Latest modifications include
the choice of ‘snap-on’ power pod at the front or a pod without the motor for
slope soaring. The latest wing now includes air brakes and ailerons.
THE NOTTINGHAM GAMSTON FLY-IN ………a truly memorable
occasion.
From small
models to large models…..from glow-plug models to petrol
motors….from prop driven models to gas turbines…..from old scale models to the
latest jet designs…….All were at the 2006 Nottingham Gamston airfield fly-in.
OK….Some of these
photos may take a while to download but they are only a small selection of some
of the models seen at the Gamston Fly-
In. The Gas Turbine models were simply Awesome to
watch with true speeds of up to 250 MPH!!!!! But all of the different types of
model and engine type added to this simple but extremely impressive and
memorable local (for us!) event. The ongoing sound system narration was
absolutely spot on with superb details of the models flying at the time along
with smatterings of true Guru modelling history. Always in our memory banks will be the 43cc
petrol engine high wing model of about eight feet wingspan that seemed to be
endlessly up there from dawn till dusk burning lead-free without a hitch of
trouble for the whole of the weekend.
The Gamston site is an old historic second world war airfield with a
huge amount of tree-free space and a full size concrete airstrip. This adds
much to the safety of the pilots when planning and flying low level passes and
eventual landings. The Model to the left shows just how big things have got since
I was a kid with my Jasco control-line balsa model powered by a Mills .75
diesel.
Trade people in
tents and marquis were there supplying loads of simple things that you simply
just forgot to bring…..to lots of new kits, ATF’s, Radio Gear and motors. There
was also a superb fast food van-unit that supplied breakfast/brunches from
first thing in the morning to last thing at night. A Saturday night barbeque
and firework display added to this superb annual event of the
We simply emailed
the club sec Christopher Moore to find that we could attend the event at simply
no cost with our caravan…… And we enjoyed every minute.
MIKE HAWKINS is into some real retro
R/C gear!!!!!
I’m real sorry to
change the subject so quickly here but I just had some mail from these two
guys, which bristled the three or four hairs left on the back of my neck! The
pictures attached with this mail show the type of transmitter that started off
the whole of this hobby of ours during the 1940’s. The first pictures show
Mike’s single channel transmitter built from scratch but to a spec from
yesteryear! Probably late 1940s. Anyway I 
will let Mike fill in the pictures (as it
were).
I have been modelling since about 1955 and used
to fly free flight on Chobham common near
Some while back I was discussing “the good old days”
with a couple of aeromodeller/radio ham friends and we decided it would be good
to replicate a system to show the young ones how easy they have got it today,
so the project was born. See accompanying photos, the transmitter is now
finished and tuned and works very well and remarkably stable for its design but
I put that down to modern components and better construction techniques that
experience has brought. I now have to build the receiver, which will be an Ivy
single hard valve (3S4) but with a transistor relay eliminator circuit. The
model is to be the good old KK “Junior 60” which I already have built and is
flying using modern radio on two channels and powered by an Australian Taipan
2.5cc diesel. I am also the Secretary of the Hobart Model Aircraft Club, http://www.hobartmodelaeroclub.org/
please visit our site.
The second picture on the right shows Mike’s circuit boards. The board
to the left of the picture with the dual gate valve is the carrier transmitter
itself while the unit to the right of the picture is a later antenna matching
circuit designed by the legendary electronic guru F.C. Judd.
Mike has recently
sent more details of further digging back into the past with the resurrection
of a legendary single channel receiver and escapement from now our planets
leaders in R/C technology! (
A member
of our club (also a radio ham) has given me an OS receiver & escapement
that he had used in the 1950’s, see attached photo, but unfortunately he does
not know what happened to the transmitter, anyway the object being to use this
in the project instead of building a receiver. As my time is very limited this
is what I shall do. I have not powered it up yet but I am assured that it was
working ok when last used in about 1958! By the way you are very welcome to use
anything I send you for your website.
73’s until next time VK7DMH.
Many thanks for
that Mike. The valve receiver is to the left of the picture and probably works
on a 45 volts battery supply with another 2 volt battery for the valve heater.
The relay (to the right of the glass valve) looks of the ‘polarised’ type.
These used an internal magnet to keep the normally closed contacts together.
These relays were very sensitive and would respond to a very small change of
coil current when receiving the Tx signal. A typical value of current change
flowing through the relay coil when receiving the transmitter signal was often
as low as one and a half milliamps! Unfortunately very sensitive mechanical
devices (relays) obviously suffered from vibration…..so invariably these
receivers had to be hung inside a fairly large airframe using four elastic
bands. The petrol and diesel engines of the day often caused havoc with their
vibration. The ‘escapement’ (the equivalent in their time of today’s servo) is
shown on the right of the picture. They used their own usually 4v5 dry battery.
Escapements were often a ‘converted’ relay but the coil windings were chunky
and allowed a few hundred milliamps to flow. Escapements because of this
healthy current flow used quite strong spring return mechanisms and did not
seem to be worried too much by vibration. Fitting of these escapements often
involved direct contact to a fuselage former. Escapements used a longish (12
inches) rubber band which was wound up to a hundred or so windings. As the
escapement clicked with each command from the transmitter it produced
sequential left and right rudder. Unfortunately, if engine vibration caused the
receiver relay to chatter…… All of the pre wound rubber band windings for
control of the model could be lost within a few seconds and no further control
over the model was achievable!
More Soon!