graeme jones

The TT instruction booklet has a photo of all 4 engines in the range on the cover, and inside. That's 54, 75, 91 and 130. The 91 is the only one shown with the large nut first, the other three show the small, slotted nut first. All 4 exploded diagrams show small nut first. In any case it's only the hex part of the nut that is "small" or "large". The small one has more threads because it has the male part of the cone. The large one has only a couple of threads because it has the female part of the cone, into which the male part fits and is supposed to lock. As I said before though, this does not prevent the prop coming off the shaft, it locks together as one piece and might just as well be one big nut. Model Stationary and Marine Steam Engines by K N Harris is the only one of my collection of model engineering books that mentions lock-nuts. It says "nine times out of ten if lock-nuts ARE used in a model (and they are rare enough anyhow) they are wrongly fitted, the THICK one should be outside, it takes the weight!" Now this is in a different context and is talking about plain nuts, but was one of the reasons I tried mine the other way round. It still came off, allowing the prop to fly off as well. Tellingly, it could be screwed back on the shaft still in one piece. By the way, the spanner I used was a bit bigger, a 400mm adjustable, but the torque that can be applied is limited by the size of the prop not the size of the spanner. The TT nuts are simply badly designed and do not prevent the prop flying off the shaft. Replace them with an OS set and at least you won't be hit by the prop, but it will still come loose. I also tried the method of having a helper switch on the glow plug once the starter was already turning the motor, with mixed results. From memory I did at least get a couple of flights before the engine stopped in the air because the prop had worked loose. The glow plug supplied with these engines is TT's own, a Red Line RF. Substituting an OS F made no difference. The fuels I tried were MT Special 4 Stroke 5% and Castor Straight, again making no difference. I couldn't get the recommended 11 X 10 prop for running-in so used a 14 X 8.

As I said in my first post on this thread, I had exactly the same problem some years ago with a TT91FS. It doesn't matter which way round you fit the nuts. I tried both and they still come off, with the prop, still locked together as one unit. Fitting an OS nut set stopped the prop parting company with the motor, but the prop still came loose. The idea of the fuel mixture being too rich can't be right either, as a read of the TT running-in procedure should suggest - "Because of the extremely rich needle setting used during break-in, you may be required to keep the glow plug igniter attached". My belief is that the metal of the prop driver is simply too soft for the job, the serrations squashing flat as soon as the nuts are tightened. Re-cutting them won't help, they will just squash flat again. My LMS did try to get me another driver from Amerang, but they were never in stock. Perhaps the solution is to fit a driver from another manufacturer, if one can be found to fit. By the way, I have a pair of TT52FS's which do not have this problem. Their drivers seem to made from a much harder alloy, the serrations being as good now as when they were made. Graeme

The exploded diagram in the Thunder Tiger 4 stroke instruction booklet shows the nut with the slots fitted first and that's the way they come out of the factory. Graeme

Merco - I had exactly the same problem trying to run a Thunder Tiger 91 FS. I was hit twice by the prop, which came off as soon as the engine started, luckily without injury. Amerang said I was running it too lean, Model Technics said it was too rich. The supplied locking nuts are useless, they just come off with the prop, still locked together. I replaced them with OS locking nuts and did manage a few short flights, the engine stopping each time in the air because the prop had come loose, but been retained on the shaft by the OS nuts. In the end I gave up and bought an ASP 91 two stroke. Before anyone asks, yes I did use a very long spanner to tighten the prop nuts. Graeme

This year's map is now available -http://bmfa-nats.org/power-nationals/airfield-map Graeme

OG - have you tried using the 7 cell pack when it's not fully charged? 6 X 4.2 = 25.2 7 X 3.7 is 25.9 7 X 3.6 = 25.2 If it's a voltage issue there should be a point where the ESC can't tell the difference. Otherwise, is there a faulty cell in the pack of 7? And have you put the throttle TRIM all the way down to trigger the arming system? Graeme PS I had a similar but unrelated problem with a K-Force ESC. Testing different batteries and props I found it wouldn't work with 9 cells, but was fine with 8 or 10. Edited By graeme jones on 04/07/2017 19:47:02

John - on a true delta i.e. a triangle, balance at 50% of the root chord, since that is 25% of the Mean Aerodynamic Chord. I've just checked my Pete Russell 363, with a root chord of 39" it balances at 19" from the tail. As you are building a scale aircraft, it should balance just forward of the main undercarriage. Graeme

Martin - I haven't seen this version of the plan but I have built 362 and 363 from the original plans. You are correct, the trailing edge is straight i.e. no dihedral. It's some time ago but I believe I used identical packing pieces all along the TE and held the LE at the correct height on a balsa strip cut to size. If you are stuck let me know and I'll dig out the original plans, on which I've probably drawn the bits needed and made some notes. I've still got one of the 363's powered by an HP40R with a tuned pipe. I can't remember what I had in the 362 but it was probably an OS20, possibly a 25FP. Either way power was more than adequate. Graeme

Martin - I've been a regular although not frequent user of RCWorld since it opened, by mail order and in person. Never had any problems with their service. Having said that, while they may have fulfilled their contractual obligation (by refunding the cost of the missing items), they have obviously missed an opportunity to score some points for customer satisfaction by supplying the OOS parts as soon as they were back in. Yes they would have had to pay the postage, but that's their problem, arising, I assume, because their computer let you order more than they had in stock. Graeme PS under the Distance Selling Regulations, you do of course have the option of sending the whole order back and having a full refund, including delivery charges. You may have to pay the return postage though, if that is specified in RCW's terms and conditions. If it isn't, they have to pay your return postage charge. Edited By graeme jones on 23/03/2017 14:30:00

Gonzo - it's even further from South Wales, and like you I'm on insulin. Won't stop me going to try the campsite out though, provided the NHS ever lets me see the orthopaedic consultant to sort my back out. That's preventing me from driving for more than 15 minutes at the moment, never mind 2 hours. Graeme

Steve - the USA equivalent is Balsarite, made I believe by the same people as Coverite. See www.coverite.com Graeme

And there's the possibility of a total ban on IC powered models because of noise and emissions regulations. Graeme

Cuban8 - it is possible to get the system to admit that the UK warehouse does still have covering film in stock, it just isn't easy to do it. See previous posts re. clicking on flags. I think the system is supposed to show the flag of the nearest warehouse to the customer which has an item in stock, provided said customer has logged in and confirmed location, but it doesn't. Mine seems to default to Hong Kong, except for batteries where it shows UK. Graeme

I was curious to see what was being posted on Hobbyking's own forum about all this, so I just had a look. Nothing. No mention at all. In fact no posts on any topic since 27 October. i.e. 10 days. Has nobody noticed or don't they care? I've tried to give HK some feedback but they haven't acknowledged receipt, too busy I suppose. No answer to my "RMA" re. the missing prop driver either. Again, too busy or don't care? Graeme

No response to my first request so I tried "live chat". Very difficult to use. Seems to have a mind of it's own, sending half of my message before I'd finished typing. Then I was asked questions which I'm sure I'd already answered in the tick boxes at the start. The outcome was that I have to complete another claim form, which I've just done. Was it this difficult with the old site? I've never had a problem with an order before. Graeme