 BMFA club affiliation No 0340
July 08
FLY SAFE - Fly Again
Next gathering at St Andrews Rugby Club, July 7th 2008 then September 1st
August is your holiday month
Mike should now have £30 off members to take you to the end of the year. I know what you lot are like - you will forget, do it NOW, thanks, it is overdue.
Our Webmaster is always on the lookout for pictures and useful info to make the site appealing and worth browsers visiting. It is one of the clubs recruiting grounds and our face to the world.
Another web site that needs support to make it a useful recourse is http://www.bmfamid.co.uk All with e-mail should have received this link from Mike recently. I have had a look and with support from BMFA members in the region it should prove to be a good discussion and information point.
A warm welcome to another new member. John Philips who is also a member of Nene Valley Aeromodelers.
I did say I was going to continue with last times guide on how to use LiPo batteries for your Rx and Tx. All I am going to say, I'll explain why in a moment, is that there are available LiPo battery packs that will fit in most Tx s. If you want chapter and verse on this mail me and I will send it. My reticence in putting it in full here is that I do have a concern. It is all to do with cold. I have to do some more delving, but as I understand it at present, during cold weather the performance of the LiPo packs reduces drastically. So all you who fly LiPo during winter lets have your thoughts.
What I do have for you is a piece I have dredged up about fuel. A bit like batteries realy; how many bottles of different fuel do you need. This bit says only one, as long as you follow a few basic rules. Many of us take fuel for granted, and use the one we have always used, because of the pretty colour. So to help you choose just one bottle to take with you read on.
1. Don't listen to the club expert / soothsayer's opinions.
2. Never leave your fuel bottle open. Methanol is hygroscopic, i.e. it absorbs water.
3. Always filter your fuel at least once before it gets to the tank
4. Running 10% nitro methane will prove fine in almost any engine, as it's a good, average mix.
5. Don't run castor oil in a four-stroke.
6. Don't believe all the hype you read.
7. Don't be fooled by the colour of the fuel, it's just a dye
8. Don't leave raw fuel in your engine, as this causes severe corrosion.
9. Check that the nitro methane content is quoted by volume (if by weight then reduce mentally by about 1/3 when spending your hard earned).
10. Be aware that not all synthetics are the same.
11. Don't store fuel in bright sunlight or in hot environments.
12. Never run your needle settings leaner than one or two clicks richer than peak rpm. Set your engine on a half-filled tank with the nose held up.
13. Using nitro methane in small percentages (i.e. 5 - 10%) will prove beneficial on any engine - even those happy on 'straight' fuel.
14. Nitro methane will shorten your flying time. The needle will need richening for any increase in nitro content, and the engine will run hotter - not cooler.
What is the 'wonder brew' then? Well, without naming names, it's a fully synthetic methanol and nitro methane mix with a sufficient quantity of clean running, highly effective synthetic lubricant that seems well up to the job.
The bottom line on fuel is that no matter what the make or name on the can, no matter what the mix or type of fuel, if it's got methanol and oil then your engine will run on it. Furthermore, provided you don't run the engine impossibly lean then you're pretty unlikely to damage anything.
It's not the fuel that damages engines, it's the operator.
Castor has all sorts of properties, some more laudable than others, and it does make a very good lubricant for model engines. However, in the end it kills with kindness. The early aero engines had to be regularly dismantled and cleaned of castor residue, as do our own, because that horrid castor gum will shellac and clog model engines something rotten. Yes it's cheap, it works, and you'll be unlucky if you seize an engine using it, but it will completely destroy your four-stroke over time as it clogs up all the little valves and oil galleries, whereupon the valves will stick open and the bearings will skip and scuff. Castor harps back to the era where automobile engines were stripped and decarbonised every ten thousand miles or so, and any engine run on the stuff soon turns brown with that 'dipped in toffee' appearance!
Running nitro in appreciable quantities will release a commensurate percentage of power. For example, running 30% nitro in your brew will give an approximate power hike of 30%, and that's not to be sniffed at. Don't unduly worry about the corrosive bi-products that nitro burners are supposedly afflicted with, given that you have to run methanol anyway, which is far worse in that respect. It's expensive and heavy, and as it burns quickly you have to carry more of it, which of course means that the more you include in the mix, the shorter your engine run time will be. On the plus side you get more power and a far less fussy engine that throttles better and runs faster. What's more, the idle performance will benefit greatly.
Hope this gives you something to think about!
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A brawl over a model airplane landed one man in the hospital and could send another to prison for more than five years. At about 8 p.m. Gregory Dean Hunt, 48, of Medford, was flying his radio-controlled model plane in a field north of McAndrews Street when a homeless man on a bicycle approached him to argue about the little plane, Medford said. "These two did not know each other," "We are not sure what Mr. Hobson's problem with the plane was. He was flying it in a safe area and was not disturbing anyone." Hobson punched Hunt in the face and kicked him, knocking out six of his teeth. Meanwhile, the model plane buzzing overhead spiralled out of control and made a crash landing. The white, turquoise and purple "Hangar 9" plane, valued at $800, hasn't been found. After beating down Hunt, Hobson pedalled away on his bike, heading south along Central Avenue. Witnesses told police Hunt then pursued him in his 1996 Chevrolet Tahoe, Budreau said."Mr. Hunt then swerved across the road to crash into the side of Hobson's bicycle and pinned his legs against a chain-link fence," Budreau said.Passers-by called 9-1-1 to report the crash, and police, firefighters and emergency medical professionals responded. Hobson's leg was broken just above his ankle. He had surgery Thursday at Rogue Valley Medical Center. He was cited and released on charges of fourth-degree assault and first-degree criminal mischief.Hunt returned to the scene shortly after police arrived and was arrested after a visit to the hospital to treat his facial injuries. He was charged with second-degree assault and first-degree criminal mischief. Second-degree assault is a Measure 11 crime that carries a mandatory five-year, 10-month prison sentence upon conviction. Hunt remained lodged in the Jackson County Jail late Wednesday on more than $1 million bail. "It's safe to say there were some poor choices made by both parties," Budreau said.
As always FLY SAFE. Stu'
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July 07
BMFA club affiliation No 0340
Hi all,
Miles here again with the AGM report.
1 - The club fee remains the same as last year, £60. Can members please send their dosh ASAP so Mike, our fearless leader, can balance the bank book.
2 - The need for a welfare officer, after Liz stepped down from this position, has been filled by Bob Blair, who is no relation to Tony, who has also stepped down. Thanks to Bob for taking it on. He is well qualified for the job as he is a school govenor and caretaker. How’s your finger Bob? More on that in a bit! This position is to comply with the B.M.F.A guidlines
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3 - Committee stays the same as voted at the AGM meeting.
4 - I.D Cards: Can all members that have paid for this year please send a mug shot to the Great Richard Hughes at his email address - rich_iehughes@yahoo.co.uk so he can issue the new card that will need to be present in your car windscreen when at the flying field.
5 - Fence: This has now been handed back to the old but goody guys who I would personally like to thank, because if the fence went wrong with me we would have had a lot of stuff all over the strip by now. So thanks for taking back the job. It was also mentioned that the battery has been tampered with and been disconnected. This conduct must STOP. If you don’t know how to switch the fence on or off please get in touch with me or Mike who will be only to pleased to show you how! Also, please DO NOT use the battery for charging other equipment. Those that are doing it, STOP IT!! Or the old but goody guys will HAVE YOU !!!.
6 - Frequencies: It has been brought to my attention again that some of the new members have not been asking other members what frequencies are being used and just switching on their transmitters. This practice must STOP as we are all aware of the risk of shooting other planes down. Not only this will be bad for ones health by the time the other members have sorted you out but you will have to go through the whole scenario again WITH ME as safety officer. And you WILL be named and shamed.
7- Lawn mower: It has been agreed at the AGM that only designated persons will use the mower. You may be a aware that it has been missused and poor old Richie, the faithful mechanic, had to put it right again. This time it has cost a lot to put right. Just one point I would like to mention is for myself for cutting the grass twice a week - donations would be gratefully received!
8 - Mike is going to get Chris to take his BMFA examiners test so that we can do B tests. So if any member would like to take the next step up the ladder, you can do so.
That seems to be it for the meeting.
Just a couple of things regarding safety:
We all know it has been a wet month and all of us are keen to fly when the sun does pop its head out, so please take your time setting up your plane, don’t forget to stake it down, which is in the BMFA rules, and one other point, be aware of what you wear! Baggy clothes can sometimes get snagged and pull ones hand into the prop', as Bob, my mate, needs all of his didgets, don’t you!
So that’s all chaps, fly safe enjoy your fingers! And pray for better weather.
Smiles from the good looking one in the website gallery!
Bye bye,
Miles
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 July 03
The Model Autogyro - an overview
The development of the model autogyro has paralleled full-size development except for the fact that it has occurred some fifty years later! There were good reasons for this as we shall see. Fixed wing models, of course, were flying successfully long before the full-size.
Principle of Operation
There is no drive to the rotor of an autogyro. The motion of the rotor and the resulting lift depends entirely on autorotation resulting from air flowing up through the rotor blades as the machine moves forward. It's exactly the same principle as applied by nature in the flight of the sycamore seed as it autorotates to pastures new.
Provided the incidence of the rotor blades and the angle of attack of the rotor disc fall within certain limits the rotor will achieve the magical autorotational state which
 produces low drag and lots of lift. An autogyro depends on a high angle of attack (of the rotor disc) to begin acceleration, and while the angle of attack remains positive autorotation will be maintained.
Even though the airflow is up through the rotor the speed of the blades through this upward airflow is such that they still manage to produce considerable lift.
There are a lot of “angles and dangles” that have to be within certain limits before an autogyro can be made to fly successfully, just as in fixed wing, and it's the exploration of these limits that make the whole subject so fascinating. The autogyro is one of the last methods of flight where there are still things to be learned and discovered or invented that the modeller can explore and make for himself.
Forward Steps
Recent advances made by a few dedicated souls have finally solved the problems of successful single rotor autogyro flight without the assistance of damping devices, such as stub wings.
The main problem that beleaguered designers has always been the dissymmetry of lift, both in models and full-size. The advancing blade produces more lift because it has the forward speed of the machine added to it. This produces a roll effect in the direction of rotation, usually straight into the deck!
One of the problems that beset would be gyroists was that while they realised the fully flapping rotor head, where the advancing blade can unload itself by rising or “flapping” as in later full size Cierva autogyro's, would solve all their problems, the weight of such a device would destroy the very performance they were trying to achieve from it. This was caused by over estimating the forces involved and the assumption that a rotor hub would have to be helicopter like and heavy. It wasn't until a Spaniard built one from lite ply and piano wire that people realised that the job could be done quite simply and with very little weight.
Not asleep yet? Well okay then, some development history at model size.
 History of Configurations
The simplest configuration at model size is to have Twin Rotors, one on the left and one on the right of the model, and have them rotate in opposite directions, thus equalising the lift produced. The blades are fixed rigidly to the hub. Control is by rudder and elevator. The rotors are usually mounted on the ends of stub wings, which greatly contribute to flight despite claims to the contrary. Dave Brown pioneered this layout in the UK through the seventies.
Next we have the Co-Axial type where two rotors contra rotate on the same shaft. This negates the rolling effect nicely and also produces lots of lift. The blades are also fixed rigidly to the hub. Control is also by rudder and elevator. Various angles are quite critical but co-ax' types are excellent fliers and can look pretty scale too.
Next we have the Teetering Head variety. The blades are fixed to the hub. The hub can pivot on the rotor shaft, so, as one blade rises the other falls. This is the system which a lot of modern full size gyro's employ but for some reason is not wholly successful at model sizes. Without some damping device, such as stub wings, the model will still roll into the ground.
Next we come to the real breakthrough, and the true autogyro; the Direct Control Flapping Head. This was invented by a Spaniard, Emilio Cabeazas, and revolutionised autogyro flying. Actually, it's virtually the system that Cierva invented for his full size gyro's all those years ago. Flapping systems have been used before but were based on heavy helicopter mechanics which were totally unsuitable for “real” autogyro use which require a disc loading of less than 5 ounces per square foot to be capable of the very slow flight for which autogyro's are famed.
 In this system each blade is hinged at its root which allows the blade to move up and down or “flap”. This gets rid of the dissymmetry of lift problem because as the advancing blade comes around producing lots of lift, it will unload itself by rising upwards without adding unwanted torque to the rotor. The system is stable and requires no stub wing or other damping device.
Plus Emilio made a gimbal device so that the whole rotor could be tilted for control in both roll and pitch. This meant the system was controllable right down to zero airspeed unlike rudder/elevator jobs where you have no control at very low airspeeds as no air is flowing over the control surfaces. Problems solved! Yet more was to come.
An American by the name of Jim Baxter simplified the design of Emilio's hub by using a flex hinge made from polypropylene sheet. This made it much, much easier to construct and worked as well as the “proper” hinges. The PP also lent itself to simplifying the gimbal too.
One other problem remained, and that was that it could take a long, long take off run for the rotor to “spin up” into autorotation, especially at larger sizes.
Enter another American, Lee Wayman. He went a step further and invented the Flapping Poly' Delta Head. What he did was to add delta to the blade hinge. Delta is angling the hinge line of the blade forward, usually around fifteen degrees. Its action is as follows:
As the advancing blade comes around it produces lift and begins to rise, but because of the delta hinge line as it rises its incidence is also reduced and this increases the rotor speed due to the reduction in drag. The higher the rotor speed the more the lift and so on. This meant that take off runs were shortened enormously as spin up into autorotation was faster.
These advances have now made possible all manner of own and scale designs that some of us have dreamt about for years. They are slightly harder to fly than fixed wing but this is mainly due to having to learn a new “method” of flying. Anyone can do it, no special equipment required, so why don't you have a go yourself?
From James Hunt
Nine years ago I moved to Rugby on business with a view to stay in a flat for 6 months travelling home at weekends. I have been here 9 years going home every other weekend.
After a month here I joined the Fennis club and made a lot of friends.
Over the last couple of years I have had a couple of blips having to spend time in hospital, last year losing 4 months of my flying time, however I was visited my some great members (you know who you are) and over the last 9 years wish I could calculate how many happy flying hours I have put in at the club. Flying is my de-stresser in life and I am going to miss it.
I want to thank everyone for the friendship I have enjoyed over this time and for allowing me to be one of your club examiners.
Time has come for me to hang up and leave my mates to return to the frozen north.
Jez, please forward newsletters to my family home, I wish to hear all the news.
James Hunt
You can join James for a “goodbye” flight after 2pm on Sat' June 28th and Sun' 29th.
Quote:
He did it alone. We had a cast of a million.
Neil Armstrong, regards Charles Lindbergh G :-)
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 July 02
An Ill Wind
Well! The month of May, and so far June as well, has been one of the longest periods of sustained high winds that anyone can remember. There's hardly been a decent flying day in the whole period; even the birds were walking. It's unlikely that a big Zenoah turning a 22 x 12 could produce such a blast. About the only flying that went on involved sweet wrappers and supermarket carrier bags. There's one flying from a T.V. aerial in my street right now.
It's attached to the house of an obnoxious little man who plays his music too loudly, let's his dog do its business on everyone else's garden and has a lawn mower that sounds like a fleet of unsilenced Hirobo helicopters hovering above your head. If you don't notice it as you walk by (the bag, not the little man or his lawn mower) it'll flap loudly `till you do. It's the best advertising Sainsburys ever had.
 Everyone's keeping a watchful eye on it in anticipation of it pulling down the entire aerial, which has already become rather floppy and leans, in calmer moments, at around 30° from the vertical. I'm looking forward to some torrential rain in the hope that it'll fill the bag with water.
I've often watched it and wondered about the stresses involved, it's a lot like those tubular wing joiners they're all using nowadays. One supermarket carrier bag full of water versus one 6 foot long, 1 inch diameter aluminium tube (already hanging at 30° don't forget) and mix into the equation 65mph gusts and the odd crow and fat pigeon. The fixing bracket looks decidedly shaky too and may yet produce a spectacular result.
Hopefully, we'll have a cold snap and the water will turn into ice, and with just a little bit of luck the whole lot will drop onto the head of our obnoxious little neighbour and justice, in it's own way, will have been served, and at least some good will have come from those damnable high winds!
Kite flying anyone?
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Bring & Buy
The Bring and Buy held at the June club meeting was a great success. In excess of twenty-five members attended and many faces not seen for a while were there. We were also delighted to see Dennis Bancroft after an absence of several years. Nice to see you again Dennis!
There were plenty of bargains to be had and several very nice models changed hands over the course of the evening. Just about everything you can think of connected with modelling was for sale by someone, and at very low prices.
All of this and lively conversation in the company of like-minded people went to make it a successful and enjoyable evening.
Trade at the bar looked good and so should ensure we keep the venue. Mission accomplished!
So, if you missed this one, do come along to the next one and bring something to sell. People really will buy almost anything! (With the possible exception of used glow plugs!)
See you at the next one?
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An Idea
There's a use for those old SLEC tanks that burst like a balloon full of water when you crash. No, really!
 If you remove the clunk fitting and rubber “O” ring you can use a couple of them to make a really good fuel and air tight connection between your fuel bottle and your fuel pump.
Just drill a couple of holes in the cap of your fuel bottle slightly smaller than the diameter of the threaded bit of the clunk fitting. Then, fit the “O” rings and carefully screw the fittings into the cap allowing them to cut their own thread. Make sure you don't drill near the edge of the cap or your pipes will foul the neck of your fuel bottle. If the material of the cap is too thin you can fit a couple of ¼” 28 UNF nuts to them as well inside the cap.
Now connect silicon tubing as per the picture. Put a piece about an inch long on the vent fitting and connect your feed from your pump to it when it's not in use. That makes the entire fuel circuit air tight when not in use and automatically vents it when it is. Good eh?
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A.G.M.
The next meeting on July 2nd will be the Annual General Meeting held, as usual, at the St. Andrews Rugby Club, and will begin at 7.45pm. You can pay your club subscription at the meeting once it's been decided what they are to be!
Please attend if at all possible and patronise the bar! Thanks.
There's no club meeting in August so see you in September!
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Free to Good Home!
From Bob Clark: If you know of anybody who is looking to start up flying and is short of "pennies" for gear, I have a 72” span VMAR Apache trainer for 4 channel and 40-46 engines. Everything airframe wise is there, it just needs radio and engine plus a set of wheels.
It's gathering dust in my garage and I would rather somebody had some use out of it. - Bob.
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Shows & Displays in July
(Model Shows in Blue)
July 6 - 7 Woodspring 2002, Yatton, Bristol.
July 7 Summer Air Display, Old Warden, Beds.
July 13 International Airshow, RNAS Yeovilton.
July 13 - 14 Flying Legends Airshow, Duxford.
July 13 - 14 L.M.A. Main, RAF Cosford.
July 13 - 14 Shuttleworth Festival Of Flight
July 20 Sunset Display, Old Warden, Beds'.
July 20 - 21 Royal Int' Air Tattoo, Fairford, Glos'.
July 20 - 21 Eastnor Castle Model Spectacular.
July 22 - 28 Farnborough Int' 2002. Hampshire
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The Fence
Last Thursday the “morning crew” found the electric fence trampled down and the cattle lying all over the strip. The electric pulse unit wasn't working and couldn't be made to work. A considerable amount of trouble was taken before it was found that someone had wound the wire around a metal post! This, of course, connects it to ground and quickly drains the battery.
The fence has to be moved periodically to allow the cattle to graze the long grass which would otherwise sour. Please do not move it to a different position! By all means lay down as many posts as you require allowing you to make your landing approach, but please return them to where you found them. If, by some chance, you have to tension the wire then wind it onto a plastic post, not metal!
Once more our thanks to the “morning crew” and especially to Derek “The Fence” Kent and “Flymo” Jeffs.
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New Model Shop
“HOBBY HUT”, 70 Lower St, Hillmorton, Rugby.
Had a nice phone call from the owner of a new model shop in Rugby the other day. The proprietor, Paul, has invited local modellers to drop in and let him know what type of things they'd like him to stock. He doesn't have a lot of experience with radio control modelling so needs your input and advice.
He offers a 5% discount to Fennis club members and can order anything you like.
So pay him a visit and have a coffee and a chat and tell him what you'd like to see on his shelves. I'm sure you'll join me in wishing him every success.
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Quote:
Air racing may not be better than your wedding night, but it's better than the second night.
Mickey Rupp, air racer and former Indianapolis 500 driver. G :-)
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