March 2014

Issue 155

FFLYPAPER (2014—our 35th year)

Do you love or hate “tray Txs”, have you tried one? I have used a tray type Tx now for over 25 years, it started when I purchased my Graupner/JR MC18 com-puter radio in 1988. You don’t have to

hold the Tx as it is supported by the neck strap and you can use longer sticks that you grip with forefinger and thumb. This, in my view, gives greater control of both sticks as you don’t have to hold the Tx as well. OK it’s a bit more cumber-

some to transport and takes up more

space but I do prefer them. My present Graupner MC22 tray also has a couple of small storage compartments for odds and ends.

I bought this new Tx in 2008 as my ex-isting MC18 was 20 years old then. It was still working well and had all the computer mixing I could wish for apart

from only having servo “slow” on one channel. I thought that reliability (100% up to being changed) may suffer even

with the 3 changes of battery I had made. I still keep it charged and it is maintaining it’s 100% record.

I chose the replacement MC22s on the basis of it did what I wanted with pro-

gramming being intuitive and logically menu driven - unlike some I could men-tion. Shame I got it just as the 2.4Ghz revolution got into full swing, it is a syn-

thesized 35Mhz system.

It operated all my existing

Rxs so no need to get new ones. I had not had any interference problems so

35 Mhz was OK for me.

It was getting a bit of a pain to ensure I had my peg for the board and the aerial

was HUGE, getting caught up in the low branches in the pits area. It was then I noticed Weatronics did 2.4Ghz conver-sions for many Txs and had a custom made one for mine. I was reluctant to change all my Rxs for new ones so the Weatronics solution was good for me as

I could switch between 2.4Ghz and 35Mhz by moving some jumper cables

about in the back of the Tx. They sub-sequently produced a switch for the Tx which means changing between 2.4 Ghz and 35 Mhz is just the throw of a (latching) switch.

So any new Rxs I get are Weatronics

ones which have inbuilt telemetry and the ability to be comprehensively pro-grammed from my PC for channel allo-cation, servo throws, servo pulse width and lots more. These Weatronics sys-

tems are used extensively by the large scale “jet boys” as the larger Rxs can

common many channels together to op-erate up to 30 servos even on different voltages.

Weatronics realised that the market for add on Tx modules was limited so are now manufacturing their own Txs. The hand held one has just been released to be followed by the tray type, this looks

“The Business”.

Whilst my current Tx is fine, Graupner no longer produce it having gone for their own 2.4 Ghz route with “HOTT” so future developments will be zero and service may become a problem. So, piggy bank permitting, I may go for a new Weatronics Tx this year. It is all

programmed from a colour touch screen or PC and will be compatible with all my Weatronics Rxs.

I was having to buy everything direct from Germany but they now have a UK

agent based in Grantham so that will make things easier and ensure we have comprehensive UK translations. All the

Rxs have upgradable firmware to keep up with developments and quality is very good - but at a price. I thought the Rxs were expensive but compared

Journal of Felbridge Flyers Radio Model Flying Club

Special points of interest:

Stability and centre

of gravity.

Tray transmitters.

Excellent brush

painting.

Solid state switches.

And BECs

Inside this issue:

Chairman’s Chatter 1 - 2

C of G and stability 2

Lizzie Build part V 5 - 6

Field report 7

NOTICE BOARD Mark at The Hobby Box has a Sale of

ARTF and RTF models at good prices up

and including 8th March. I will post it on the forum and send to all members with the newsletter, if you are interested give

him a call before you go.

Chairman’s chatter Chairman’s chatter Chairman’s chatter --- and and and

disdisdis---connected ramblings ?connected ramblings ?connected ramblings ?

Page 2 Issue 155

to the new Futaba Rxs they seem good value.

--oo00oo--

I will be using solid state switches in my new gliders (no ESC to provide Rx power). I have used Multiplex, Jeti and Emcotec so far and they seem very good. Some incorporate voltage regulators so you can use 2s LiPos (or 5 -6 NiMh)

and provide 5 - 6v for the Rx and some just provide a

switch for whatever battery you are using with no volt-age regulation. Some have magnetic actuation for the

switching and some a physical switch which carries very low current and if it fails will not turn off the power supply.

Using one of these means you can use the higher en-ergy density LiPo batteries, trying to fit a 2200 2s LiPo in one of my gliders I found that it’s length was not

easy to accommodate so looked at what Overlander had to offer. They now do a 2500 5 cell NiMh which is much shorter than the LiPo and will fit the nose of the aircraft much better so don’t discount these new series Eneloop batteries. A 2500 pack takes up the same space as a 500 pack of only a few years ago.

--oo00oo--

Most 2.4Ghz Rxs can work with power supplies of up to 9v so 2s LiPos can be used directly (do check if yours

can though!). However most servos will burn out if the voltage is over 6v, hence the advent of High Voltage (HV) servos. If you want to use 2s LiPos, or 5 cell NiMh packs to power your Rx directly but don’t have any HV servos you can get some tiny voltage stabilisers that sit between Rx and servo for £5.25 from Hyperflight. On a 4 servo model this is cheaper than a voltage sta-

bilised switch.

--oo00oo--

Now that’s what I call a “bang” - in 1883 when Krata-toa erupted the bang was heard 3000 miles away, now thats LOUD.

“800,000 year old footprints found in Norfolk” - who are they trying to kid? These footprints, suppos-edly made all this time ago, were washed away by the action of the tide in a couple of days after discovery - why then weren’t they washed away a few days after

being made all those years ago or at some time in the

intervening 800,000 years? I wonder about the ar-chaeologists who come up with these fanciful ideas - or is it me?

Last November the Met office issued their 3 month pro-jection. “For the December to February period there is a slight signal for below average precipitation….. there was 25% chance of winter falling into the driest cate-gory” and what do we get - the wettest 3 months since

records began. You would have thought that with all their computer systems, bright graduates and historical

data they could do better than that. Perhaps the wind and rain blew their seaweed away!!!

Opinions expressed here are the personal ones of the editor not necessarily those of Felbridge Flyers.

Stability, C of G and longitudinal Stability, C of G and longitudinal Stability, C of G and longitudinal

dihedral dihedral dihedral

How often have you heard the comment “The tail is low in the air so the C of G is too far back”? Providing the aircraft is being flown at normal speeds (and not so slow it is about to stall) the way it sits in the air

depends on the angles of the wing, tailplane and thrust line, it has nothing to do with the C of G.

The point that the wing lift acts (Centre of lift) is nor-

mally behind the C of G. As the forward speed in-creases the lift increases and the plane would tip for-ward around the C of G as the lift would increase but the weight of the plane (acting through the C of G) would not. This “couple” of forces needs to be bal-

anced by a downward force at the tail, this in provided by the tailplane. The tailplane is normally set at a lesser angle of attack than the wing so it produces this downwards force. This angle between the wing and the tailplane is known as longitudinal dihedral or de-calage.

As the aircraft speeds up the lift increases, the “couple” of forces makes the nose want to drop but

the tailplane produces more downforce to counteract this, result - stable flight.

The further forward the C of G is the more force the tailplane will have to exert to balance the aircraft, this is why the elevator control is much less sensitive with a forward C of G and why it is more sensitive if the C of G is closer to the centre of lift (or more rearward). If the C of G moves behind the centre of lift things get

very interesting as you would need an upward force at the tail to balance the forces, as the tailpane is de-

signed to produce a downward force the result will be a very out of control aeroplane with extreme longitudi-nal instability, result - CRASH.

So, ensure the angles of the wing and tail are as shown on the plans and ALWAYS ensure the C of G is within the parameters shown on the plans, if in doubt

err on the side of caution and have the C of G at the forward limit.

Often the C of G is shown incorrectly due to typos or metric/imperial conversion problems, so if it is not around 1/3 cord back from the LE (on a conventional

straight winged aircraft) seek confirmation. There are many mathematical methods to calculate the correct position so double check using these web sites:

http://adamone.rchomepage.com/cg_calc.htm

http://www.geistware.com/rcmodeling/cg_calc.htm

No, you can’t change the C of G by moving this symbol about you have to redistribute the weight

in the airframe!!!!

Norman

PS I did run this past our honorary aeronautical con-sultant, John Farley, who confirmed its accuracy.

CLUB NIGHTS

CLUB NIGHTS

CLUB NIGHTS

CLUB NIGHTS

CLUB NIGHTS and other events

CLUB NIGHTS

CLUB NIGHTS

Saturday 15th March - Club meeting and in-

door flying at Sackville School sports

hall. Flying from 14:00, Club business at

around 14:30. No charge for those not fly-

ing. There will be individual 5 min slots for

the larger shock flyers.

Wednesday 2nd April - Sausage Sizzle &

Glider Guide at fernhill Riding, start

19:30. bring alone a chuck glider for some

light hearted competition, Sausage BBQ

for a small charge.

Wednesday 7th May - AGM at The Haven

Centre 20:00.

Page 3 Issue 155

Friday 10th January - Not a bad weekday flying day, warm (for January) with good sun and a wind straight down the runway. Had to push out John Dowd from the recently cleared, but not yet consolidated, winter parking

extension.

Saturday 11th January - Sunny and warm again with a light crosswind. Got Pete Blake’s new foam powered glider model going in better conditions than for its first

flight. Got him some air time even though the Tx that came with the model had no buddy lead. Used the “panic grab back” method but he was coping well and chuffed to bits to get flying. Had to tow his car out though as he got

into the soggy stuff to the right of the track.

Kevin Hill has a plan built model designed by that perma-nently grinning d****y Alex Whittaker, he named it “Bertie” as his wife thought it looked like a liquorice all-sort. It flew pretty much like one as well…… It would not stop climbing. Kevin thought this was a C of G problem but it was one of excessive longitudinal dihedral. The

wing was at too large an angle of attack relative to the

tailplane. We spaced the LE of the wing down by a 1/4” using a pen as a spacer and it flew much better. Kevin will reshape the wing cutout to suit.

Saturday 18th January - Indoor flying at Sackville School, good turnout for some relaxed flying, segregat-ing the larger “Shockies” and having separate sessions for slow fly, helicopters and fast & furious meant mid air collisions were rare. This was a combined Club/indoor

meeting. Keith Lover came along for the meeting so we let him have a fly with some Vapors which he seemed to enjoy, he quite liked the Tx trays so will be looking for

one.

Sunday 19th January - Another balmy midwinter day, warm sunshine and light winds. Great turnout to enjoy the conditions. Muddy underfoot in the parking area and across the field and got a bit soggy in the pits but strip

very useable. We got John Prior’s new D B Piper Chero-kee flying but all was not well. Trimmed out well and fly-ing at half power with no problem, time to climb to check the stall when it dropped into a spin, too low to recover. It came down in the field to the north in a dense bramble bush, prop blade broken, some damage to the cowl and a few small dents in the port wing, otherwise undam-

aged.

Not sure why it spun, C of G in the correct place, eleva-tor throws small and model turning with power on. Turn was quite steep so may have G stalled or motor may not have been providing power as on a previous outing a few days before water got into the ESC and the motor would not run. John had protected it from water since though.

Club night 5th February - Members brought a diverse range of models from large to virtual. Dave Nice had his

Flair Fokker Tri plane which at 85” span is pretty big and beautifully built; in the early stages of construction,

wings not yet started. Kevin Hill brought along his quite small Dragon Rapide, well the top wing and tail anyway. Keith Lover had his virtual Flying Flea, he brought some photos.

John Prior had his almost complete Tiger Moth air-frame from D B Models, this is a perfectly sized model of the Tiggie in my opinion, he has only had the kit for 2 weeks or so, needless to say he is re-

tired. Ian Dinan had his self built quadcopter which had a brief flight in the room, well done Ian, experi-

mentation is not dead.

I brought along my new ASW 27b and my old/new Phase 6. The fuselage and tail is the 30+ years old original but with a new wing (the old having split veneer and much crazed paint). I have put individual servos for each aileron and programmed crow brak-

ing to make slope landings less of a lottery.

Mike Dyke brought is ARTF Fiesler Storch, which is mid sized and looks great, even has matt covering applied which looks nice and scale. He will need to wait for the better weather to fly it as it has tiny

wheels.

I am beginning to wonder if these Club nights are worth the room rent, perhaps we should just have the AGM and one “big name” speaker in the winter

season with the formal Club meetings as part of our indoor flying sessions as we have partly done this winter? Any views?

Monday 10th February - Managed to get a couple of flights in-between the storms, John Prior and me managed to wade to the strip which was dry enough for John to fly his foamy Acro Wot; I hand launched

my small flying wing - good to blow the cobwebs

out.

Saturday 15th February - Indoor flying at Sack-

(Continued on page 4)

Whats been happeningWhats been happeningWhats been happening

Page 4 Issue 155

ville School. Good turn out of members. Jeremy Clark brought along his 2 young boys to spectate, they en-joyed it. Quite relayed flying as the 3 hour sessions make it less frantic and everyone gets to fly without the

room too crowded. Simon and Kevin demonstrated something I have not seen before - a Vapor doing an outside loop! These are the more recent Night Vapors as I can’t even get my original to do a normal loop. Ian Di-nan got a good flight with his home built quadcopter, impressive.

Sunday 16th February - At last a flyable Sunday, good

sun, wind down the strip, exceptionally clear and 8 de-

grees. Only 5 of us turned out, one in the morning and four in the afternoon. Wet underfoot but strip useable with drains doing as well as can be expected. Perhaps a few of us went down slope soaring……(but I expect Stu-art wished he had waited for stronger lift - see Forum).

Lots of Buzzards who were unimpressed with our models as they thermalled ever upwards.

Wednesday 19th February - Getting fed up with the mud and water and longing for summer. Reasonable day

with wind straight down the strip. Four of us turned out

to fly but did not stay long.

The muddy water splashes on your trousers leaving muddy marks that when dry leave dusty smudges where you have been sitting. There is mud in the car boot where your willies have been, mud on the interior of the doors and seats where you swing your legs in and the car gets dirtier and dirtier which makes it look bad as I

seldom clean my car anyway. You can’t put your model down without it getting covered in muddy water and your wellies give you a wet bum when you kneel - ohh, when will this rain EVER stop? And just to cheer you up

we have March to come which often proves cold and snow to look forward to at Easter. Do you get the feeling that this terrible winter is getting to me…………..

Wednesday 26th

February - A bit drier underfoot and a good bright day with a sometimes blustery wind, got caught in a short shower. Kevin did

a low pass a bit off

line and got caught in the hedge. John Prior recovered the model and it was flying later.

Taj Manning of Mid Sussex Flyers with the BMFA S E

Area have been trying to get model aircraft flying

introduced to our young people. They have ap-

proached schools with a view to coming in to run

sessions but got little enthusiasm from that area.

They expanded this to ATC units and the enthusi-

asm is there.

On 15th February Stuart Willis, myself and a few

other interested members from local Clubs met at

Crowborough Training Camp to help get the cadets

interested by building and flying some BMFA Darts.

It gives you faith in our young people. They were

kitted out in their smart uniforms, showed great

interest, were exceptionally well behaved and to cap

it all - called me “Sir”. Thinking of introducing this

as a new Club rule at the AGM - don’t think that will

be voted in. One of our “old boy” members, now

living on the Isle of Man, used to call be Sir which

he said was spelt “Cur”…..

Crowborough Training Camp is extensive with MOD

security, parade grounds, cinemas, gym, lecture

rooms, dormitories, etc. Those helping were dined

in the Officer’s Mess. During half terms as many as

300 military cadets can be on site. It is a little “run

down” and in need of some decoration but must be

just post war. With the current emphasis on reserve

forces it may well get a makeover.

We all brought along a selection of models but one

really stood out. It was a D H Cirrus Moth that was

quite large with exceptional realistic finish and de-

tailing. It was

built by Tim

Maslen, here

is a picture to

whet your ap-

petite, I have

asked for

some more

details, I will

feature it in a

future news-

letter. Yes, it

is fitted with the OS in line four.

Air Training CorpsAir Training CorpsAir Training Corps

The nose of Tim Maslen’s Cirrus Moth

Thank you Overlander

On page two I mention an Overlander 5 cell NiMh eneloop pack for one of my gliders. When it arrived I found that a 6 cell

pack would fit in the space available and reduce the nose weight I would have to put in the model.

I contacted them and, yes they could add an additional cell in the configuration I needed. They would weld in the conduc-

tors, incorporate my powerlead and shrink wrap it for me if I posted the pack to them with a drawing of how the cells

need to be configured.

I posted it an a Wednesday afternoon just before the Post Office closed and it was back with me on the Friday morning,

all for just over £8 including return postage - great service Overlander.

Page 5 Issue 155

Well it is now early Feb 2014 and my Lysander is fin-ished all bar a little fettling here and there. I had hoped

to be at this stage by Christmas 2013 but I had some

issues with the slats which I had to make again, no problem as first flight will not be until spring anyway if the weather ever gets better.

The original slats which I made months ago warped badly in storage and the impact adhe-sive joining litho plate to balsa failed so these were as much use as a sun roof on a submarine and went in the bin. Sticking anything to litho

plate is not easy but its such a useful material in modelling I tried experimenting and found that RC Canopy glue does a great job. I cov-ered the new slats with glass cloth and resin straight away and no warping problems now.

So on with applying paint. I cannot spray paint to save my life so have become reasonable at brush painting over the years and Spectrum

enamel will brush on well so the entire model including roundels and letters is brush painted.

Fortunately the colour scheme is a fairly easy

one to do, grey/green camouflage on top and

all black undersides so grey first followed by green, then all the black and in quick time the models was looking more like a Lizzie. For the roundels and letters I made mock ups in paper to see how they looked and

when happy made stencils from sticky back plastic, this worked well with little or no colour leakage. The roundels re-quire building up in several stages which is time consuming but

straight forward.

Painting the ex-haust system a realistic colour can be very diffi-cult as the hues tend to be very subtle and on full size aircraft the exhaust system

changes colour according to its temperature. The Lysander has an exhaust collector ring built into the cowl as do many other aircraft and when cold these appear grey / silver and a coppery shade

when hot. So I experimented on a test piece ap-plying a coat of silver paint and while it was still

wet brushed in some black to dull it down a bit

and then worked in some very small amounts orange and I ended up with a gunmetal base with some cop-pery highlights. This looked ok to me so I tried it on the model and it went well. When it was dry I rubbed

in very sparingly some powdered pencil lead to dull the fresh looking paint a little. Gem of wisdom here – you can lead a horse to water but a pencil must be lead.

Now all the painting was done time to install all the equipment, receiver, engine, tank, onboard glow etc. During construction I had been checking how the C of

G was looking and moving what I could to get it right

without ballast. This paid off as the C of G is good with the tank empty. No doubt this happy result was assisted by using a heavier engine than Dennis Bryant would have used but he like all the designers of those

Lizzie build part V Lizzie build part V Lizzie build part V --- Max Max Max WoodheadWoodheadWoodhead

Page 6 Issue 155

days had supplies of helium filled balsa to build the tail end not available to us mortals.

During building I put LED lights in wing tips, tail and spats.

I could have bought a commercial unit to switch these on and off via a radio channel but I chose to make my own. If

you take the amplifier from and old servo, discard every-thing else, the out put of this can drive a mini reed relay

instead of the servo motor so you have an RC switch for very little work/cost. Well I wired it all up, it works and I even got the red and green nav lights the right way

round.

My Lysander wing has six ser-vos and two lights so twenty two connections that have to made to attach the wing. Originally I used Multiplex six way connectors for this but

this was a bad choice as they

are difficult to plug/unplug. I replaced these with two twelve way connectors that

are so easy to use with one hand in a confined space. While I was at it I retro fitted my Kyosho Spitfire with this connector making five plugs down to one and no more plugging flap into aileron and

taking the wing off to fix it.

I finished off making a dummy radial engine from scrap balsa. Before flight I need a pilot figure but I

do not have one yet so I weighed the model as is and it is 4 oz over target at 10lb 4oz without pilot figure. I could reduce the weight by leaving out the on board glow system and be under the target but will leave it in place. The wing loading is 32 oz per sq ft. Some say the wing cube loading is more im-

portant guide, I don’t know about this anyway WCL is 14.3 but is that good or bad ? We will see.

So now I must wait for first flight and imagine how it may go. First objective get air-

borne and deal with trim prob-lems, second objective find out about slow flight and the stall without delay as landing is compulsory, only then if its still flying get a pass in for the

camera, day dreaming mode

off.

Max Woodhead Original in the National Aeronautics & Space Museum USA

Page 7 Issue 155

Committee and General Journal of Felbridge Flyers Radio Model Flying Club

Editor:

Norman Carter

“Mertony”

Furzefield Road

Baldwins Hill

EAST GRINSTEAD

W Sussex RH19 2JN

Phone: 01342 327077

Email: felbridge.flyers@btconnect.com

Home page: www.felbridge-flyers.org

Current Committee:

Chairman – Norman Carter (01342 327077)

Secretary – Chris Searle (01342 325535)

Treasurer – Ian Stone (01342 870661)

Mem. Secretary – Andy Musgrove (01342 719424)

Webmaster & BMFA rep – Stuart Willis (01293

402733)

Member – Bob Cutter (01342 713175)

What a wet and stormy start to the year, surprisingly our

field drains are working well and most of the water is piped

to the stream which has, on occasion, been very full.

Some sheep got into the fields in mid January, fortunately

apart some hoof marks no damage. After a week they were

rounded up and put into a field with secure fences in Shaw-

lands Farm.

After the continuous rain on 31st January the field was

largely underwater but it drained off in 24 hours, see the be-

fore and after pictures of the summer parking area and

stream.

We are planning

some work on

the winter park-

ing area, The base is firm as much

rubble has been laid over the years. The problem is a layer of

mud on the surface. We are expanding the area and will lay

more rubble. We will scrape off the top layer of mud before

Field Report Field Report Field Report

consolidating the

area with some

crushed concrete

or limestone. It is

work for a ma-

chine so are work-

ing on arranging

this when the

ground gets bet-

ter, if the rain

ever stops.

I HATE WINTER!!!!

Daffs doing well