 BMFA club affiliation No 0340
August 08
FLY SAFE - Fly Again
Next gathering at St Andrews Rugby Club, September 1st then October 6th
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.
CLUB?!!
I have rattled on before about what makes a club a good vibrant club. In my experience flying clubs have a wonderfully diverse membership. All sorts of people from all sorts of backgrounds. The one thing that brings them together is a passion for flying. But to keep the club dynamic there must be more! Social interaction (club meetings etc) with discussions, perhaps some fun flying competitions. To be honest, anything to keep interest in the club buoyant. A club made up entirely of individuals will keep struggling from crisis to crisis, reliant on the goodwill of the suckers who year after year keep the committee manned. I understand the pressure on time from other sources, but when you join a club you make a moral commitment to the club. i.e. not just to take for granted a flying site, but what you can give back in return. Introduce a new member, help a less experienced flyer, listen to others and exchange ideas.
I would encourage you to take a look at some of the photos below of the last gathering of my French club.
    LiPo's
After my foray about LiPo's a while ago I have received the following from Wayne Giles. Many thanks (I have included the graph, and it saves me writing anything else!!)
Although I am no longer a club member, I still get your newsletters and saw your comment about poor LiPo performance at low temperatures. I am attaching a plot I did over two years ago comparing a Kokam 3200 3 cell pack with a 9-cell GP3700 NiMh pack. Both types were the best available at the time for electric powered flight. If you look at the plot of ESR (Equivalent Series Resistance) against temperature, you can see why LiPo's are struggling at low temperatures. From 35*C down to 5*C, the ESR of the NiMh pack increases by 36% whereas the LiPo increases by 104%. This means that the load regulation; i.e. the volt drop at the pack on load, of the LiPo more than doubles at the lower temperature. This is a function of the electrochemistry within the pack and therefore applies to all LiPo's. A further problem affecting the life of the LiPo is also relevant. At low temperatures and high currents, the self - heating effect (I2R) in the LiPo is much greater and will almost certainly shorten the pack life. I believe this to be a major cause of early Lipo failures, as does Bob Smith (See his "Technology" column in June's issue of Quiet and Electric Flight.)
Regards,
Wayne.
 As Always, Fly Safe,
Stu'
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 August 06
BMFA club affiliation No 0340
FLY SAFE - Fly Again
For those of you who have their glasses on we start the new newsletter year with a new masthead - well spotted.
Next gathering at St Andrews Rugby Club September 4th - Monday
£60 subs to Mike ASAP we are still the cheapest in the area, with well cut grass.
Don't forget Lads, check the website frequently (those of you who can) for any breaking news and info, and please pass on info to make sure everyone knows.
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Well we have had our customary summer month off from the monthly meeting and the newsletter. No doubt many of you have been holidaying in exotic places and others have had more time to fly. I know our esteemed President has been over the pond, not to the manic bit below the 49th but to the civilised bit above, Canada. Hope you had a good time Tom.
The scorching heat of late should have given the glider boys hours of fun. There were certainly some superb thermals about. On a slightly more sombre note, the nights have perceptibly started to draw in; so do make the most of the evenings we have left. The late summer and autumn late afternoons and evenings do offer some splendid flying times. We do have a great flying area, so get out there, and put it to good use.
As you all know the club strives to run on the lowest subs it can survive on. To that end, it has been decided to save on postage costs by issuing the hard copy newsletter bi-monthly. The majority of the newsletters are delivered via e-mail anyway. To make sure everyone is in the know of breaking issues, Jez our Webmaster, posts breaking news on the FFF website he so lovingly maintains. So I ask you web users, when you see other members make sure they have the news you have.
Notes of the AGM Meeting
Club balance sheet
The balance sheet had been included in the Newsletter issued on the 16th June, with the treasurer's recommendation to increase the subs. to £60
Election of Club committee members.
Tom Webster was re-elected President.
Mike Pearson was re-elected as Secretary Treasurer
The secretary read out the report from the Safety Officer explaining the need for a safety representative at the field. After some discussion, Miles Wood was elected as Safety Deputy under Safety Officer Stuart Cooper. Stuart was re-elected as Safety Officer.
The committee will review whether it is appropriate that Miles takes the BMFA A certificate.
Allocation of other club tasks
These are unchanged: Mike Downs continues to assist with mailing of the Newsletter, Liz Butler continues as Welfare Officer.
Agree next year's subscriptions.
It was agreed that these should be set at £60.
Any other Business
There was some discussion concerning the development of the Marina and its possible impact on the Club.
The excavation is now proceeding rapidly. We do not have a date for when berths become available. In previous discussions with the farmer and developers it has been indicated that they do not consider our flying to be a problem so the expectation is that the club can continue using the present site. We have to see how the situation develops. There may be a possibility of relocating again within the Fennis Fields if necessary.
Mike Pearson
Secretary
On to other things now.
Don't forget to keep the gate locked on entry and exit please.
Mike is still keeping a watchful eye in conjunction with the BMFA on the proposed air traffic order surrounding Coventry airport. I will keep you up to date if anything happens! As the wheels of bureaucracy turn somewhat slowly - don't hold your breath.
A bit more on electric thingies.
This may well be a bit simple to most but it is a very simple explanation.
Do you understand milliamps??
Remember to get more out you have to put more in, i.e. you have to charge for longer, or charge at a higher rate.
Formula for charging empty packs,
1) Add 20% to value of capacity, i.e. 800mAh becomes 960mAh
2) Divide by charger output, if you have a 60mAh charger it will take 16 hours to charge the above.
Look at it this way; you see Rx packs for instance with 500mAH or 600 mAh or more written on them. Think of them as 5 gallon, 6-gallon etc. fuel tanks, i.e. the larger the number the longer the running time, it does not mean that the pack is necessarily any more powerful. In fact quite often the higher the mAh in the same size of cell can mean it is less powerful. It is like comparing a sprinter with a marathon runner, the bigger number will run forever but does not pack the punch. So a big number is great for transmitters and receivers, but it is not always the best for motor running.
FLY Safe, fly again and enjoy - make the most of the weather while it lasts! Stu'
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 August 03
Annual General Meeting Report
Mike Pearson reviewed the past year and stated that in his opinion the club subscription should remain at £42. When this proposal was voted on it was carried unanimously. So, if you didn't attend the meeting - only about twenty members did - please forward your next year's subscription to Mike without delay. The club year commences in July, so until you have paid up you are technically not a member. Get out that cheque-book NOW!
He went on to outline the position as regards the proposed marina construction and the consequent loss of our beautiful strip, which has never looked better. However, it appears that the sale of the land is not yet definite, and that if we have to move the farmer will allocate us a suitable portion of the field where the gymkhana was held. In point of fact, we used to fly there in the early days, so all should be well.
The only other matter raised concerned the number of recent crashes attributed to radio interference, and the possibility of the club purchasing a frequency monitor. However, it was pointed out that a frequency monitor gave no assurance that interference would not occur during the course of a flight even if none were present before take off. Further, there would be problems as to who should look after the monitor so that it was generally available at the field, and the subject was not pursued.
Note: There will NOT be a meeting on Tuesday 5th August as this is the peak of the holiday season. The next club meeting will be held on the 2nd September.
Electric Fence: We have had several instances of the cattle trampling down the electric fence recently. If you don't want your model covered in revolting, evil smelling cow-dung every time you land - and cow-pats have an almost magnetic attraction for models - then close the fence gate and switch on the current if you are the last to leave the strip. For those with poor memories UP IS OFF (mnemonic - U PIS(S) OFF!) and surprise, surprise, DOWN (ON) is the opposite of up!!
My thanks to Charles Aitkenhead for the preceding information.
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More Autogyro Stuff
 Much to my surprise there was a lot of interest in the autogyro article of last month - even though it was mercilessly hacked to fit - with many kind comments and requests for more information, especially as to the design and construction of the rotor hub. I promised several people that I would do a follow on showing the hub construction, so here it is. Everything is made from 3mm lite ply except for the hinge material, which is Polypropylene No5, and the bearing sleeve, which can be brass or aluminium tube. I used aluminium tube with an outside diameter of 10mm and an internal diameter of 8mm (about £3 from B&Q for a metre length) and running sealed 8mm x 3mm ball races (available from any model shop that sells r/c cars). This allows the use of a 3mm Allen cap bolt for the
 mast and nylock nuts for hub retention, which greatly simplifies transportation as the rotor is easily removable. The glue used to assemble the bearing tube to the hub centres is 5 minute epoxy. The hub shown is suitable for rotor diameters up to around 36 inches. Beyond that and you'll have to scale everything up a little and use slightly thicker PP for the hinge material. I'm currently using .030 inch thick PP on a 32 inch rotor with complete success. Revs are in the order of 1200 to 1500, which I found surprising.
As the rotor diameter increases, so the revolutions decrease, so some balance can be found between blade mass and rotational forces on the hinging material.
Tests (not mine) have shown four blades to be the most efficient, very closely followed by three blades. More than four shows no benefit, and two are very poor and have other problems all of their own.
Note the incidence shims on the blade tangs. These are merely strips of 1/32 inch ply about 1/8 inch wide attached to the upper surface at the leading edge of the tang and set the angle of the blade compared to the hub.
I hope the foregoing is useful to those of you interested enough to have a go, and if you are interested enough, be prepared for all the strange looks you'll be getting in B&Q and so on whilst measuring polypropylene containers with a micrometer! Q
Any Use?
Where was the C.G?
You know how it is; you come to fly a model you haven't used for a year or two and realise you have no idea where the C.G. is located and, as ever, you can't find the building instructions! To overcome this problem when you build or buy the model just insert a dress making pin into the bottom of each wing on the C.G. point once you have it finalised, then you can never forget. It's also useful if you are experimenting with moving the C.G. around as you have an inbuilt reference point to work from. The head of the pin makes a nice Braille locator for your fingers too!
And..
Solarfilm Backing & Oil
If you're restoring an old model which will involve a re-cover, you may be interested to know that cellulose thinner dissolves the coloured, adhesive backing of Solarfilm which is usually left all over the airframe when removed.
Also on the subject of restoration; if the model is oil soaked a good method for getting rid of it is to lay a couple of layers of toilet tissue over the affected area and iron with a very hot iron. Replace the tissue as it absorbs the oil and keep this up until the tissue remains clean, then wash down with methylated spirit. Leave for a day to dry thoroughly and then apply several coats of 50/50 thinned Clearcoat. When dry cover with your choice.
On The Grapevine
The word on the strip is that the “morning crew” are fast becoming known as the “Frog Club”…
Why?
`Cos they're all just about to croak! :-)
Okay, I'll get me coat…
Quote:
Here's to me in my sober mood
As I ponder, sit and think.
And here's to me in my drunken mood
As I gamble, sin and drink.
When my flying days are over
And from this world I pass
I hope they bury me upside down
So the world can kiss my ass.
- Anon. G :-)
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 August 02
A.G.M. Report
A good turnout attended the A.G.M. on July 4th, in excess of thirty members being present.
The meeting was opened with a vote of thanks to Derek Kent and his helpers for their efforts with the electric fence.
The balance sheet was discussed and approved by all present. Next years subscriptions were then discussed, the outcome being that no increase in fees was considered necessary for next year. The meeting therefore approved a subscription of £42 as per last year without any controversy.
If you didn't pay your subs' by the end of the meeting, please post them with a completed application form to Mike Pearson. (Address at the end of this newsletter) These are due from 1st July so please don't delay for too long!
Bill Sewell addressed the meeting to say that he no longer wished to be considered as club chairman unless elected to this position. No vote was taken on this, but the view of some members was that officers of the club should be seen at the field fairly frequently, and Bill's business commitments had prevented him doing this other than on rare occasions in recent times. The matter was left for further consideration.
The subject of Safety Officer was discussed, as Chris Bland, our current Safety Officer, is not rejoining, so the post will have to be occupied (to satisfy B.M.F.A. regulations) by someone else. It was pointed out that one person could not be ever present at the field and so should we have two or more officers? When volunteers were requested no one was prepared to offer their services, so once again the matter was left in abeyance.
There being no other business, apart from complaints about the field mowing which have already been addressed by Mike Pearson, the meeting was closed.
Don't forget, there is no meeting in August, but we hope to have a speaker for the September meeting.
Thanks to Charles Aitkenhead for this report.
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Other News
Safety Officer
Further to the A.G.M. report; Stuart Cooper has volunteered his services as Safety Officer. Stuart has rejoined our club this year and has some safety experience.
Any safety issues you have should be directed to him. See him at the field or `phone -
Thanks Stuart. It's appreciated.
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“A” Certificates
Our B.M.F.A. examiners, James Hunt and Mike Pearson, want people to go on a list to take their “A” certificate. It's my understanding that testing will take place on weekends. Ring Mike if you want to be added to the list.
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Help?
Dave Willis asks, “Is there any club member who is willing to spend some time at weekends to instruct me?” Dave is only available then. Please help if you can, as I know Dave is on the verge of selling up unless he can find someone to help him along.
Ring Dave.
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New Members
I'm sure you'll join me in extending a warm welcome to our newest members. Welcome all!
One member who has rejoined after an absence of many years is Barry “Castor” Clay. Barry is a lifelong modeller and has been seen at the field with many unusual aircraft over the years. If you need any advice on modelling matters just ask him. He also used to be a sign writer, so I've chucked him a couple of sheets of aluminium for new signs at the field! So when they appear you'll know who to thank! Thanks Barry.
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Norman Wilkinson
Norman, who is 80, has recently returned home from hospital after a major operation. I'm sure you'll all join me in wishing him a speedy and full recovery. He's been flying for many years virtually one-handed after suffering a stroke. How he does it I don't know. I've tried it and I can't do it.
Norman was a Halton boy and served with Second T.A.F. in WW2. If there's anything you want to know about Mustangs, Lysanders or Typhoons, he's your man! He has more hilarious anecdotes than anyone I've ever met. Plans are afoot to reform Bat Squadron (he knows what I'm on about!) so hurry up and get well (enough to fly!) soon Norm'!
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Shows & Displays in August
(Model Shows in Blue)
3 - 4 Woodvale Rally. RAF Woodvale, Nr Southport.
10 - 11 Large Model Assoc'. Duxford, Cambridgeshire.
15 - 18 Eastbourne Int' Airshow. Eastbourne, Sussex.
17 - 18 Large Model Assoc'. Catton Hall,
18 Shropshire Air Show. Sleap, Wem, Shropshire.
24 Sunset Flying Display N°4. Old Warden, Beds'.
24 - 26 Yorkshire Giant Model Spec'. Rufforth, Yorkshire.
25 - 26 The Great Yorkshire Air Show. Elvington, Yorks'.
31 Battle of Britain Airshow. Shoreham, Sussex.
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The Fence
On Saturday 6th July at around midday the wire was once more found wrapped around a steel post! Please, if you have to wrap it around something then make sure it's plastic!
No further problems since this though. Fingers crossed!
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Gate Keys
New members, or those who have lost theirs, can purchase a gate key to the field for £2. Available from Mike Pearson or myself.
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Hobby Hut
Paul from Hobby Hut, 70 Lower St, Hillmorton, Rugby, has asked me to include his opening hours, so here they are:
11 - 4 Sundays
12 - 8 Weekdays
Closed Wednesdays
10 - 6 Saturday
The Sunday opening could be useful, eh?
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Adverts
Don't forget you can advertise your for sale and wants in this newsletter. Provided you let me have them about a week before the end of the month I can include them here. See me at the field, e-mail or `phone.
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Quote:
Professor Focke and his technicians standing below grew ever smaller as I continued to rise straight up, 50 metres, 75 metres, 100 metres. Then I gently began to throttle back and the speed of ascent dwindled till I was hovering motionless in midair. This was intoxicating! I thought of the lark, so light and small of wing, hovering over the summer fields. Now man had wrested from him his lovely secret.
Hanna Reitsch, German test pilot describing the first helicopter flight. G :-)
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