Piers Bowlan

No one mentioned Cyril Carr's Avro 707. Nice looking model if you are a lover of 1950's deltas. Is anyone planning to build one? I had the plans blown up 150% at my local copy shop. Looks promising... Edited By Piers Bowlan on 23/11/2013 19:06:51

My wife's Disco 3 has an electronic hand brake and this is a right pain. The car started drawing attention to itself by screeching very loudly when the brake was 'switched on'. It got so bad that something had to be done as I was worried it would get stuck on somewhere or worse, 'let go' all by itself!. The LR dealer said that it needed a new servo unit;- £1100 plus fitting. However, I have the car serviced by a father and son business and they are really great engineers. They re-fitted the offending unit which fixed it but even this necessitated dropping the suspension first. What a design! That was a couple of years ago but it has now started 'screeching' again so I have told my wife to leave the car in 'Park' (it is an auto) and not to apply the hand brake. It is complication for the sake of it, the mechanical hand brake on our old Disco 2 never needed any attention. I won't bore you with the fun and games we had with the electronic tailgate lock!

On a more serious note Bandit, if you have noticed some squirelly behaviour in flight then I assume that you have a reasonable amount of differential dialled in to your ailerons either mechanically or on your Tx? Aileron differential will counter adverse yaw if it is present. Also, have you tried some coupled aileron and rudder? Another thought is to try moving the C of G forward a tad (technical term), this can have a secondary effect of improving the yaw-roll couple (although it will improve pitch stability at the expense of elevator authority). I think someone mentioned counter rotating propellers as well, - this is worth a try if not very scale. In fact anything that reduces the aeroplane's tendency to yaw will be helpful in reducing the naughty wing dropping tendencies that the aeroplane may exhibit. Nice smooth flying is helpful. Don't over bank on the base turn and, like I said, keep your airspeed up. Like my (full sized) flying instructor said to me many years ago whilst discussing false landings, 'it is better to over run the landing strip at taxying speed than to stall the aircraft in on the approach. The former you will probably survive, the latter you won't!' As for people who can 'see' the pitch attitude of a model aeroplane when it is on the approach, - they must have better eyesight than me!

Yes an aircraft can stall at any speed and in any attitude. Is this helpful and stop Bandit writing off his DH88 - Er, no! BEB has the answer- don't move the elevator. Job done!

Hi Bandit, Reflexed ailerons may help, as will flaps to some degree, although they do have the effect of moving the centre of lift inboard and therefore making the aircraft laterally less stable. Not so good. Wing washout is the real solution but short of building a new wing this is not much help to you. Have you considered fitting a gyro to the rudder channel? At the point of stall if the aircraft is not in balance (skid or slip) it will tend to drop a wing in the direction of the yaw and auto-rotate into a spin if not checked. Many factors can cause the aircraft to yaw, from adverse yaw caused by the ailerons, slipstream and lateral balance to name but three. However if the aircraft is in perfect balance it should stall straight ahead, even in a turn. However in reality very rarely is the aircraft in perfect balance. Other factors that can affect this behaviour is whether the aircraft is climbing/descending, turning, C of G position, configuration and power. The DH88 does not appear to have a very big rudder so perhaps loss of rudder authority at slower speeds may exasperate the loss of directional stability and so a tendency to yaw in the critical landing phase. Fitting a bigger rudder to a graceful scale model is not an option but a gyro to help tame this wing dropping tendency might be of help. When all else fails keep your speed up! Just my 2p worth.

Steve, I take it you measured the voltage of each cell of the battery? (they should be pretty much the same). Have you got (or downloaded) the instructions which tell you if/how you can change the LVC setting of the ESC. It should also tell you how to change the ESC timing although I have never had to do that - yet.

It seems unlikely to be the battery & much more likely to be the ESC . Steve, buy another battery AND ESC and if it turns out to be the motor then we are all wrong!

Lithium batteries (ion or polymer) carried by passengers and crew as carry on baggage must be for Portable Electron Devises (cameras, phones. computers etc.) and must be OEM which are tested and certificated (not copies or fakes). Therefore regardless of their Watt /Hour rating they are not allowed on passenger aircraft either as hand luggage or manifested cargo. No LiPos are allowed as checked-in baggage. So, no, you can't legally take your LiPos with you on an aeroplane. Link here. As you can't take glow fuel either that just leaves a glider to take with you on your hols -as long as the Rx pack is not a LiPo!

I would second what WolstonFlyer says. I would put my money on a duff ESC but check all the wiring for bad joints etc. I have good service from the Turnigy Plush ESCs too. There is no such thing as an ESC that is too big in my book! A watt meter is a good investment, I have had mine for years. Good luck sorting it out.

Stephen, The Fantrainer has a short tail moment and long nose moment, necessitated by the rear mounted engine/motor. it also has a small fin/rudder or at least much of the tail is in the turbulent slipstream from the fan, reducing it's effectiveness. A bigger fin and/or a longer tail moment would make it more directionally stable so less likely to fish tail. Just my 2p worth. Piers.

Hi Bill, it is all about the amount of heat in the tip of your soldering iron, not temperature. So you need 100w or even 200w and a really big copper bit in the end of your soldering iron. Tin the wire to be soldered and the plated connector in the XT60 plug. Push the wire into the metal plug and apply heat to the side of the tinned plug. The solder will melt and the wire will slide into the hole in the plug. As he said you must plug a male and female plug together when soldering or you will ruin a lot of plugs.

Wot's a computer virus? (Shouldhavegotamac) now retreating to the bunker!

In the mag pro-plan article, Cyril makes reference to 'Balance as necessary to get the C of G in the position shown on the plan...' Unfortunately I cannot see any reference to this critical piece of information on the plan. On page 66 the photo caption says, 'The C of G isn't absolutely critical so don't fret too much in this respect'. So not much help there then- but I will try not to fret! Great model though, I will watch your build blog with interest Dane.

Thanks Daz, I have bookmarked the link and will give it a go sometime soon I hope. I have a fairly major house rebuild /extension on the go at present so don't even have a workshop just now!

I like the nose hinge idea for battery removal (I might copy that!). What are you using to stop it hinging in flight?

Fascinating stuff Daz and a real insight into a form of construction I have not considered before. I must give it a try, although not with something quite so challenging! Do you use a cad program for designing all the component parts? Last question, where do you get your grey depron from? Piers

Very impressive Daz, thanks for showing us. I have not used depron before, if it is not a silly question how do you get the complex curves of the fuz, particularly the nose. Also what did you finish it with?

Robin, I have two or three of these 40A switch mode Turnigy Plush ESCs and very good they are too. Having said that I would use the 60A version if my motor/prop combo was drawing 39A, regardless of how hot the ESC gets. The extra weight of the larger ESC is minimal in the scheme of things especially considering just a few years ago we had to contend with the weight of a NiCd pack! As for cost, how much is your model worth compared to the cost (your cash and your time) of a replacement model? I have just checked the spec of the G25 motor and I see it says 32A max and 44A for 15sec. So maybe a smaller prop (11X8) might be a good alternative option with your 40A ESC. Alternatively use a bigger motor (and ESC) . Edited By Piers Bowlan on 08/10/2013 05:23:38

1). Dragon Dancer 2). Miss Lizzie 3). Swamp Rat 4). Mini Jazz 5). Whizzza

'Cheap battery powered helicopter', surprised it had a LiFe battery. Anyway, the battery sounds shot so try a 2s 1300 mAh LiPo. Yes you will need a new charger. I would think this might do and is cheap enough, here. It all depends on how much your boss wants to spend on it to get it flying. As far as the higher voltage of the LiPo is concerned, try it and see. If it is not flying now, it can't be any more broken than it is!

Looks wonderful Tony. Will you be flying it at The Hastings MFC Autumn Fly-in, 25-29 September or is it still at the testing stage? Looking forward to the plans becoming available - hopefully before not too long.

I think HK have a cracking web site which must be one of the reasons why the company has become so successful, UK LMSs please note. There is stacks of product information and specifications even if some people might have issues with the accuracy of it sometimes! Then there are all the product photos. How many sites have you seen with just one out of focus picture and no close ups. I think the best thing about about the HK Website are the reviews. If you see half a dozen negative comments about an item in your basket then you have been warned! Perversely people still seem to buy some items that are clearly turkeys. As always, buyer beware! Off thread slightly (sorry) I have bought a couple of cheap and cheerful models from HK that have been a load of fun even if the quality was not great-I wasn't expecting much for the price. I have also bought stacks of servos without a single failure- perhaps I am just lucky or maybe it's that I read the reviews carefully as well as other forums.

Nice one Percy. Plan still available from My Hobby Store, Ruhig Tigre, plan MAG 147. I will have to look through my collection of old RM mags to see if I have Nov 1990 although I don't remember it. Could be a home for my OS 52 FS. A winter build perhaps. Is it too early to mention Winter?

Martyn, when you remove the landing gear don't forget the nose gear is responsible for quite a bit of nose weight, so removing it will move the c of g aft. You will need more weight in the nose as the LiPo won't move any further forward. I used a 3300mAh 4s Lipo which did the trick as well as giving longer flight times.

Paul, the fan unit of my (silver) kit version Vampire was not glued in but held in place with bolts through plastic mouldings. Perhaps HK have reduced their QC on this product line? The Wemotec mini fan pro from Puffin models is priced at £35.95 on their Website. Just make sure you specify the right adaptor for your motor shaft, 2.3mm, 3.2mm or 4mm. I didn't have any problems with my fan unit, perhaps I was just lucky. I wouldn't bother to add a wing spar as the wing is thick with lots of glueing area, it;s as tough as old boots- I have tested it! . Do reinforce the booms though as Martyn said. Two strips in each boom, one along the underside and the other at 90 degrees on the inside, along the length of each boom terminating mid-chord of the wing. Just make sure the carbon strips are correctly inserted into the slots and you haven't accidently introduced some bend in the booms before you run cyano into the slots. One last point, make sure the servo wires cannot get sucked into the fan!