Newsletter Spring 2017

From Our Chairman, David Richardson 

I don’t know if you noticed, but we have had some very mixed weather since I wrote last.   Over the past few months some of us have, however, managed to get out and do some flying.    We have been hit by some very cold weather recently.   This extremely cold weather has certainly curtailed our sport.  In spite of the bright sunshine the Lipo batteries do not like the cold!

Let’s hope the weather soon warms up and we can look forward to a spring of regular flying!’

We have a club trainer again.    This means that my Wot 4 foam-e is retired from training. The trainer comes with two Futaba Transmitters and is ready to go. We also have a foam Cub which comes with two Spectrum Transmitters. Both trainers are kept at the field with the transmitters locked in a safe. A number of people have the combination so the trainers should be available when you need them. 

The footballers have, so far this season, restricted themselves to the new pitch on Saturdays.   I don’t know about Sundays. 

We have a group on WhatsApp (see next article)  to tell us who will be at the field. So far there are about nine members who have joined. I always phone one member (who does not have a mobile phone) if he doesn’t appear by two fifteen. 

Please join the group and use it. It makes it so easy to find out who is going. That includes trainers and pupils for those still practicing for their 'A' test. 

A Happy New Year to all.

 

Whats up with WhatsApp?         from Nick Coldham                                       

                It is very useful to be able to know what is going on, be it with family, friends or for social activities like model flying. I first used WhatsApp to organise meeting up for cycling rides in the Surrey hills. WhatsApp is an App (application or program) that you can load onto your smart phone and use to either set up a new group or join an existing group. Each time a member of the group sends a message then you will be copied in and you can, of course, send messages yourself.

The club has set up a group, currently called LMFC (Leatherhead Model Flying Club), which is in use to communicate about flying down at the field. This would include who is going down to the field and when. So yes, this is social media and now owned by Facebook

https://en.wikipedia.org/wiki/WhatsApp .

Because it is on your phone it is very accessible and quick to use; just like sending a text. You can also use WhatsApp to make free phone calls (VOIP - voice over internet) and send photos or documents. You can find out more about how it all works here.

https://www.whatsapp.com

To get started you need a smart phone with WhatsApp loaded. You can load up WhatsApp onto your phone by going to the App store, and searching, or by simply Googling to their web site. If you want to join the club LMFC WhatsApp group then you need to text me (07887668620) as the WhatsApp on my phone needs to know you are available. I can then add you to the club group and you will start getting messages.

If you want out then you can either block chat from a certain group or remove the WhatsApp from your phone.

And what does all this cost? The WhatsApp app is free and the messaging is over the internet and of very small size so most likely to be well within your monthly data usage allowance, so nothing.

You can also load WhatsApp onto your laptop computer (WhatsApp web) which will communicate with WhatsApp on your phone (over your WiFi). It is all very easy to use.

So there we are, that’s WhatsApp, as I understand it and I recommend it you. Let us know when you are next coming down to the flying field! 

 

Why wheels?  From Ian Harvey (Club Secretary)

I sometimes see power model take-offs and landings which, even on Frank’s perfectly tended runway, either nose over and reconfigure the prop (tail draggers) or reconfigure the nose leg (trikes). And I think - I have it so much easier – hand launch and belly land and no one raises en eyebrow. Because generally gliders and e-gliders don’t need or have wheels. Life is so much simpler.

I do wonder why more members don’t fly gliders. Even aside from the beginning and end of the flight, the flight itself is so much (more) fun. Searching out the little bits of lift (sometimes big lift) is challenging, totally absorbing and very satisfying. I generally get 20-30 minutes flying time out of a 1½ - 2½ minute total motor run time.

A 20 second motor run will take me up to about 600ft and from then on it’s “where’s the lift”!  The tree line along the Mole provides wind-generated lift with an easterly or westerly wind. Exactly where it is depends on the wind direction. There is also often good lift between the Recycling Centre and the Mole. But the biggest lift for some reason tends to come somewhere in the middle of Barracks Farm field on the far side of the river. It’s probably thermal lift and sometimes there is a little cloud above the area of lift – I wonder why.

I have a vario in some of my gliders and I have topped out at about 1200 feet when I can barely see the 4m glider and it still seems to be rocketing up. I get quite nervous when the flaps and crow are full on and it still doesn’t want to come down. Then the choice is either “big dive” with its attendant risks of things falling off when you pull out of it. Or, put some reflex on the wings to speed things up and zip quickly off to one side, hoping that you don’t lose sight of it meanwhile.

So far, touch wood, I haven’t lost a glider OOS since about 1960. That was my Inchworm competing in an SMAE National free-flight glider competition at Llangynidr in the Brecon Beacons. The slow burning dethermalizer fuse failed to work and the plane was about 12 minutes to out-of-sight. Although it gave me a silver medal (which I still have) that was the last I saw of it until about a week later when I got a letter saying that it been found undamaged - about 40 miles away near Port Talbot! So I know the power of thermals and the need not to underestimate them. But – hasn’t our sport come a long way since then!

Which leads me to say – “give gliding a try!”. You don’t need a big or complicated glider. There are some excellent 1m and upwards foam models which are quite inexpensive, fly well, catch thermals and bounce. We now have a club trainer e-glider and I would be very happy to buddy with you on that (see photos below).

I have the ambition this year of doubling (to two) the number of glider flyers - so, do give gliding a go! Drop me an email (ian@ianharvey-ip.com ), a WhatsApp message or phone me (07802 323 175) and we can take it from there.

 

 

Training notes – not just for trainees

by Geoff Bignold with a
brief note by Dave Richardson
 

Checking that your model is airworthy is vital to safety and also saves you money. It helps to know what can go wrong so that you know what your checks should cover. The only trouble is Murphy’s Law: - 

“If it can go wrong, at some time or other, it will.”  

Here are some examples of what can go wrong with a simple control linkage involving a servo, a push rod, a control horn and a control surface (e.g. elevator or rudder). All of them have happened to club members while I have been a LMFC member.

Servo

Mounting screws loose or missing – the result of vibration, or of drilling the mounting holes too big, etc. Check them before the maiden flight and again quite regularly.

Servo arm centre screw too loose or missing – usually caused by forgetting to tighten after adjustment. Easily checked – not to be forgotten.

Control slops due to worn servo bearings and/or enlarged hole in servo arm –

replacements may be advisable.

Push-rod

Insecure end-wire bindings – again a potential source of control slop. Ensure that the bindings are well made and supported with good epoxy resin (I used balsa cement on my first model – it was not up to the job and I soon had to reinforce it with Araldite).

Use of threaded couplings (e.g. to clevises) at both ends – if the rod can rotate it is possible for it to become unscrewed at one end. Lock nuts can be used to prevent this but it is better still if you only make one end adjustable and have the other fixed so that the rod cannot possibly rotate.

Clevis detachment from control horn – use of a clevis sleeve, either a commercial one or one made from fuel tubing can help to avoid this.  

Clevis thread wear – eventually (and it came as a surprise to me too!) the vibration can cause the thread to wear so much that detachment of clevis from rod becomes a possibility! This happened on my antique Wot 4. Admittedly it did take quite a lot of flights but replacement of the clevises was urgent by the time I discovered the problem.

Control horn

Loose fixing screws – wear and tear generally results.

Fatigue failure of the control horn itself – another surprise that caught me out. An elevator horn broke in flight. I was lucky - separate elevators with independent horns gave me enough remnant control to enable me put the model down gently in some soft vegetation, which saved the day.

Control surfaces

Broken, split or unpinned hinges – this is perhaps the most common fault. It is important not just to rely on glues. If, during a flight, a control surface ends up dangling then the chances are that you will be going home with a bag of bits.  

Range Check

Transmitters are able to transmit at reduced power in order to perform a range check.

With 27 and 35 MHz transmitters you leave the aerial collapsed. With 2.4 GHz transmitters it is a setting. You must learn how to do this simple procedure and carry it out at the field:

  • When you fly any model for the first time
  • If you make any changes to the electronics
  • Regularly at least Monthly

Failsafe Check

All models are required to have a failsafe. Generally this is restricted to the throttle and means that without a signal the model has no power. IC the throttle is set to tickover, with electric the motor stops.

With some transmitters the model can be set to circle as well.

To test the failsafe on your model set the throttle to some intermediate setting and then turn the transmitter off. After a brief pause the motor should stop (or reduce to a tickover).

This should be carried out at least as often as the range check.

Doing this means that you are less likely to lose your model.

I could go on… but I think this is already more than enough to make the point. Even unlikely failures can and occasionally do happen. Keep checking – it is important.