Geoff S

Posted by Donald Fry on 17/04/2016 12:34:45: I think you refer to a Futaba standard plug. Grind away. But be aware the ridge is there to prevent you getting the plug in the wrong way round, so note the wiring before you grind. And be careful you don't grind all the way through to the contacts. Certainly be aware of not grinding your way right through to the contacts but connecting the wrong way round isn't a problem. It won't work but neither will it do any damage, which is the main worry. If you get it connected wrongly simply turn it round. I hate those Futaba ridges because it often means that connectors that should mate, don't. Geoff

If it's a DB Cirrus Moth 58" ws I'm pretty sure CoG is 4"/100mm back from the L/E of the top wing in the centre. Check at DB S&S web site but I'm pretty sure that's a very safe setting to start from. Geoff

Here's the method I use successfully on my Stearman for holding the interplane struts. The fuel tube holds the struts very firmly and even without it the struts are quite difficult to remove so the chances of any problems in flight are minimal. The bolts are held permanently on the wing at the top and the strut at the bottom. Geoff

Sunny today at Ashbourne but breezy and chilly. Hadn't flown my Stearman for over a year but I've experimented with a gyro on the rudder to keep it straight on the take off run. The last time I flew it, it swung violently to the left and was impossible to hold. It had never been that bad before. As I was about to install the gyro I noticed the wheels were very worn and some years ago I remembered fitting new foam wheels to a Precedent Funfly which also made it squirm so badly on take off that even the best pilots couldn't control it. So, as well as installing the gyro I also changed the wheels. It seemed to be fine on take off today but with such a strong breeze it was off in 3 or 4 metres anyway. It's a pussy to fly but the wind made landing a bit tricky and I aborted the first attempt but managed a greaser the second time. I decided to quit whilst ahead after the wind strengthened and became quite turbulent. Enough to blow over my Riot on landing and breaking the gears on the rudder servo and, later, to blow the model onto my transmitter and breaking the Perspex arm on the Frsky transmitter tray. I suppose you win some and lose others. Pleased to survive GreatPlanes Super Stearman with Mackay 30cc petrol engine/Hobby King electronic ignition and Krumscheid silencer (which seems quite acceptable in flight) Geoff Edited By Geoff Sleath on 17/04/2016 21:59:53

Silencers on petrol engines are a big issue and these look promising. I got my Stearman out a few days ago. It hasn't flown for 18 months (something of a hangar queen, I'm afraid) so I checked out the engine at home as a first step to getting it back into service. It's a 30cc Mackay with a Krumscheid silencer that cost IIRC in the region of £90. The first thing I noticed was that it's far from quiet despite the expense. Perhaps I'm biassed because I fly mostly electric now but a really effective silencer would be a huge improvement. I remember my 1932 Scott motor cycle was also very noisy but teenagers don't worry about things like that. As an elderly adult I prefer quiet power Geoff

I wear glasses anyway but I'd certainly wear them as protection at our winter indoor flying sessions. We mostly fly small fixed pitch helicopters (eg V911), small 'toy' drones or Vapor or other lightweight fixed wing models at quite low speeds. I don't really think there's much danger to life or limb except eyes. That demo could apply just as easily to any model, multi-rotor, helicopter of fixed wing with either an electric or liquid fuel driven prop/rotor. Geoff

Posted by bert baker on 15/04/2016 11:18:36: I don't have either flying or landing braces on my 58" Tiger Moth but the system is similar to this. In my case I made the hooks go through 180 degrees so the can't come out as long as the top is restrained. The need almost to lie on the wing before they'll unhook. Geoff

Do you mean the interplane struts? I have a Great Planes Super Stearman with a Mackay 30cc petrol engine, which may be a similar kit to yours (they did both). I also got fed up with fixing 8 bolts to hold the IP struts, particularly as all the threaded components are those strange US only imperial threaded ones I've grown to hate. My first step was to fit 4mm bolts at each fixing point, permanently attached, which meant all I had to do was fit the nuts. As I have a stock of metric nuts it wasn't the end of the world if I lost one. But it was still a pain. I ended up replacing the nuts with normal fuel tube, which is a tight fit on a 4mm bolt and the thread stops the tube from sliding off easily. That's much quicker and seems to work perfectly well. Having said that, DBs idea I use on my 58" Tiggie is even better - hooks into eyes at the bottom and a 14g bike spoke pushed through eyes and held with an elastic band at the top. The eyes are simply modified split cotters. Look on DB S & S web site for details. Geoff

Posted by Delta Foxtrot on 13/04/2016 12:19:15: My definitions for what they are worth: Drawing up and building from your own plan: scratch build. Starting from a plan: plan build. Starting from a kit: kit build Assembling an ARTF: assembly. I am sure there are other shades and that this is subjective, but the words ought to describe what is involved in the process of making a model aeroplane. Edited By Delta Foxtrot on 13/04/2016 12:19:35 Now there's an intermediate step between 'Plan build' and 'Kit build' because we can buy a set of CNC cut parts for the plan of our choice but it's not a kit as such because it's still necessary to source all the other wood and parts And there's ARTfs and ARTFs. IIRC my foamie Riot took about an hour to put together when I got it home - in fact I thought I was just looking at my new purchase and then realised I'd 'built' it. OTOH I have an ARTF Great Planes Super Stearman which took my a very long time to complete. A lot of the time was taken up fitting the Mackay 30cc petrol engine and deciding how to install the radio gear took more than 5 minutes. But it doesn't matter at all. It's whatever you prefer to do and most of us do a bit of each. Geoff

Posted by Peter Miller on 14/04/2016 12:53:15: Correction. Size Zero + is 50" span, 470 sq. in. Whatever the wing span, Peter, it sits very nicely in the air and looks the part. Just a couple of questions. 1: Have you employed the plastic paper binder idea you suggest for the Ballerina. It looks like it. 2: It appears to have quite a short moment from wing to tail feathers. Does it affect elevator control? It's certainly up to your usual high standard of design and construction. I really must get on to finishing my Ballerina Geoff

Posted by Martin Harris on 10/04/2016 21:01:49: 5 Ah is a bit over the top for most sports models, but it could have a place in a large model - especially with digital servos. Personally, I avoid NiMH for anything serious. I just don't trust them... Edited By Martin Harris on 10/04/2016 21:04:02 Really? I would trust a good quality subC NiMh pack any time as a receiver pack. Just cycle it to check its capacity and performance if it's an unknown quantity. They have the advantage of being safe to charge in the model which helps a lot if the battery is buried within the fuselage. The Instant large capacity AA packs are OK if you don't expect them to deliver high currents. They have a high internal resistance. I wouldn't use them in a large petrol model for the receiver and servos but OK for electronic ignition where the current draw is modest. However, I would never use any charger that didn't give me information about how much energy had been stored in pack. Those wall wart chargers should never put on one side gently - they should be thrown with great force against a solid brick wall so they are smashed beyond repair. In the case of the OP just charge the pack at around 2 amps, then discharge it and note how much energy the battery stored. Do this 2 or 3 times to ensure it's reliable then go fly. Geoff

The main problem in the first case is replacing 400 brushed motors with brushless outrunners mechanically. It depends on how easily they can be accommodated in the existing nacelles. Assuming that's reasonably easy then lets assume the weight is still 40 ozs (2.5 lbs). The rule of thumb is 100 watts/lb for good performance and with a scale model that's not expected to be aerobatic that will be more than ample. So with a 3S LiPo (11.1 v but I usually say 10v on load to be conservative) 250 watts or 25 amps total (12.5 amps per motor). So you need to find motors that will spin appropriate diameter props and draw roughly 15 amps each. You'll also have to have 2 esc (each motor will need its own) but they're fairly modest and won't be very expensive. Select ones that will cope with (say) 30 amps and they'll stay cool. If you already have the second model with its Astro high quality brushed motors then just fit a 3S LiPo that'll fit and keep the weight/CoG within limits. If you haven't got the Astro motors already then a similar set up as above will be OK. Browse HK's web site for examples. Geoff

Depends on how you've set up your 3 channel model. Assuming Mode 2 (ie throttle left) if you have put the rudder on the RH stick where you'll have the ailerons as the main steering control with 4 channels then you'll notice very little difference. Quite honestly it's a myth that a 3 channel model is easier to learn on than a 4. In fact I think 4 channels is easier because, as you've noticed, things like rolls are much easier. I suppose the models are easier to build but that's it. I built and was taught to fly on a 4 channel conventional trainer. I think the first 3 channel model I built was a Lazy Bee long after I'd passed my A certificate and now I mix 100% between 'rudder' (on the LH stick) to 'aileron' (on the RH stick) because I kept trying to steer it on the ground with the wrong one . Geoff

If it's a simple on/off switch (ie not a change over/ two way type) then your only option if you want it to be the UK convention of up=off and down =on then you have to turn it over, physically. The wiring will make no difference. Geoff

Stewart also played the part of Charles Lindbergh making the first solo transatlantic flight in Spirit of St Louis. Geoff

Posted by John Privett on 09/04/2016 11:16:41: Posted by Denis Watkins on 08/04/2016 09:31:53: 2mm spacing board mount stand offs But it's 0.1" spacing - ie. 2.43mm Actually 2.54mm I'm sure John had a slip of the finger. Geoff

I'd agree with Martin, particularly when the first sentence of the article is: "The internal resistance provides valuable information about a battery as high reading hints to end-of-life." Even poor batteries can maintain their capacity (energy) whilst being unable to deliver useful current (power to a first approximation). Geoff

How does a Taranis measure each cell unless you have a suitable telemetry unit connected to the receiver (via the S Port?)? You must have to connect the balance plug to something. My Frsky telemetry enabled receivers only report on received signal strength (RSS) or voltage without additional units. What are you using and which of the values in your opening post refers to its results? I've only ever added a battery current telemetry unit but cell IR might be interesting to measure, though not as useful. Properly made measurements of IR are quite possible but they have to be done properly. Measurement of supply source resistance or impedance is an old established technique and well understood. It just needs to be done properly under defined conditions. I use a Wayne Giles meter and it gives similar results to my iCharger and the values are consistent with what would be expected of old and new packs. Geoff

Posted by Ben Kelly on 06/04/2016 21:43:07: Hi Geoff, I hope you don't mind but i decided to have a go at removing the wind turbine from your photo to give it, as you said, a more vintage look. Not at all, Ben . I've removed unwanted items from photos of mine in the past. However I rather like that wind turbine. It doesn't intrude on our flying but gives an indication of both wind direction and strength. Our quad fpv fliers tell me its about 800 metres away. Geoff

It's quite easy to make an estimate of the effective series resistance (ESR) of the whole pack assuming you have a wattmeter. Just measure the voltage off and on load with a known current. ESR = offload voltage -on load voltage /current. Dennis Watkins: Measuring IR or ESR of a cell puts no undue strain on the battery and certainly less strain than in normal use. Whether it puts any strain on the user depends whether or not you like to know how your power system is behaving. Me? I like making valid measurements. I suppose because I made a living doing it for 30 or 40 years. Geoff

I'm a bit confused. Which is the Taranis telemetry reading, presumably from a Frsky telemetry device? Quite honestly I wouldn't trust any of those readings because they are so different. The 7 in 1 readings are definitely wrong. Any cell with an IR as high that would deliver almost no usable current. 100 milliOhms at 20 amps would drop 2 volts at the battery terminals for each cell, so with a 4S LiPo that would be 8 volts - over half its nominal value. Find someone with either an iCharger (which gives IR readings during charge) or, better, a Wayne Giles meter and use that as the standard to compare the other readings. Geoff

One of our members who was a very competent self taught heli pilot turned up with a medium sized aerobat ( Cap?) with an OS52fs engine he'd bought rtf on eBay and proceeded to test fly it. He took off, did a few circuits then rolled and looped before a slightly rough but reasonable landing. Our club chairman asked him how long it was since he flew a fixed wing and was surprised to hear that it was his first ever flight not on a simulator! So Martin may well have a perfectly successful career with a 'proper' aircraft Geoff

Posted by Biggles' Elder Brother - Moderator on 05/04/2016 18:47:41: Hehe! Love the idea of an SE5a doing strip long knife edge! BEB Well, I have seen Ian Redshaw prop hanging a well overpowered 1/4 scale SE5a I'm not much of a whizz-bang pilot but I do really try to fly smoothly and gracefully with lots of touch and gos as often as not. There's often a spin at some time, too. Though occasionally I play silly beggars with my electric conversion Limbo Dancer but prop hanging is beyond my capabilities. Geoff

Well, I suppose the thing I hate most is crashing Fortunately, I seem to do less of that these days than I used to, which means my model storage is getting fuller and fuller as I can't resist acquiring new models either through building or buying artf. Which leads me to the thing I seem to be having most difficulty with - selling models to make room for more. Buying's easy but selling involves cleaning up, checking over, photographing and either advertising or taking to a swap meet (something I haven't tried). I really must do it because I want to buy and build a DB Cirrus Moth and won't have anywhere to store it if/when I do. Geoff

Yep, so did I. Just watched it on the iPlayer. Moreover it looked like a proper workshop and James was wearing proper workshop clothes and had dirty hands and fingernails. Tom Sharpe : We got married in 1967, too and my wife is still using the Qualcast Super Panther push mower I bought her at the time - well you don't marry a market gardener's daughter and do the gardening yourself, do you? Geoff