Robin Colbourne

On the P-38 Lightning the propeller rotation was changed after the prototype crashed, so there is something to be said for 'suck it and see.' Castoring nose or tailwheels are for masochists only. If your twin has a central rudder, then a linkage to that with a spring inbetween would be the first choice, otherwise a servo for the tailwheel steering again with something inbetween to take out landing and 'hangar rash' knocks. Having the pivot for the tailwheel leg canted forward like a bicycle handlebar stem reduces the likelihood of shimmy, with the ridge on each side of the tyre as per the DH Mosquito & Avro Lancaster is the ultimate solution.

There is of course a way of running a two stroke 40 that will turn a big prop... 😃

Phil, I wasn't suggesting that one was done intentionally to clear the heather, however it does help when done properly. When I used to fly free flight at Chobham Common next to the M3 in Surrey, the Ranger encouraged the users of the common to join in clearing the pines and silver birches. If left to get too tall, the saplings were a hazard to models; so of all the common users, the modellers were by far the most enthusiastic puller-uppers of the young trees. They would all be gathered into a big heap in the centre of the common for the Ranger to do a controlled burn mid-week. Needless to say, one year the controlled burn wasn't quite as controlled as the Ranger intended, and he was the one that set the common alight... 😂

Several reasons, as Paul says, it will sound right for a start, a screaming two stroke on an Edwardian-style aeroplane is a bit incongruous. Other reasons are that a four stroke is better for swinging a big prop. For maximum efficiency at low speeds you want to move a large diameter of air backwards just a bit faster than the aeroplane is going forwards. As the Elder 40 isn't going to be screaming around the sky like a pylon racer, that means big diameter/low pitch. A bit like auxilary outboards on yachts, the low geared British Seagull turning a large diameter prop is a better bet for moving a largish boat than a having small prop spinning at high revs. Another reason is that a lot of these models of First World War and earlier aircraft turn out to be tail heavy, and rather than adding lumps of church roof (lead), you might as well have that extra weight in the form of a more appropriate engine. One last thing is that four stroke silencers are a lot smaller, so you won't have a big metal lump ruining your model's appearance.

Whilst it is sad for the wildlife directly affected, the burning of heather heathland is beneficial for limiting the spread of gorse and invasive species such as silver birch and scot's pine. Clearly it is better that it is done in a controlled manner than wind-driven wildfires.

Cuban8, I fully agree with you that a fourstroke would be a better bet, however that was not the question Adsjking was initially asking. Its a little like the anecdote of someone in rural Ireland asking the way to the capital, only to be told. "If I were going to go to Dublin, I wouldn't start from here." The Thunder Tiger 46Pro is a very nice engine, so if Adsjking already has one in nice condition, he may well be able to do a good part exchange for a .40 to .52-size four stroke.

Thunder TIger's own recommendations are a 10x6 or 10x7 for the TT 46pro, However as yours is a slower flying model, maybe an 12x5 or a 13x4 would be better. Sceptreflight haven't got an engine test for the Thunder Tiger 46Pro, however they do for the Tower Hobbies 46BB, which is going to be pretty similar. I would be aiming for around 10,000rpm. A finer pitch prop will get the model off the ground more quickly and give a better climb rate, whereas a coarser pitch prop will allow lower revs in straight and level flight, so the model will be quieter.

There is a lot of fuss made about the USA being the largest market for R/C models and equipment, however it would be interesting to see a bar chart showing by just how much this is. Other countries have larger populations, and with the increase of the standard of living in South East Asian countries, they must be fast catching up on the US. This article suggests the worldwide market in 2022 was worth US$6.2 billion in 2023, and at the time of its writing it was projected to reach US$10.8 billion in 2032. The war in Ukraine must have increased the sales of hobby items that find their way into the huge number of drones being used there, whilst at the same time the negative effect on the global economy of the war will have hit hobby sales to some extent. Edit: If this article is to be believed, the US hobby R/C market is only US$ 228 million, which sounds a bit low as a percentage of the US$6.2 billion above.

Has anyone any idea what the effect wil be on us, of tariffs on imports to the UK by American companies e.g Horizon Hobby, if the products themselves come straight from China to their UK distributor (in Horizon's case, Logik RC)? I suppose the other question is whether the European/British end of US companies be treated, either now or in the future, as separate entities?

There are UK supplied calibation tools for around £355 from the Castle Group and from Aliexpress for around the £100 mark. Companies such as Calibrate.co.uk would calibrate yours for you. Do you have a local amateur radio club, or a member with contacts in one? I find amateur radio people to be pretty well equipped with all sorts of test gear.

The use of Loctite type products on models runs the risk of it getting onto plastic parts. This can cause them to get stress cracks and break up. I realise the servo in question was 'all metal', however it is quite possible that nylon hinges and control horns could be used and get contaminated. This is what Loctite themselves say on their 648 Retaining Compound technical data sheet: This control horn on the right is from one of my own models, showing what the effect is. This fell apart when refurbishing the model for use after a number of years out of service As I recall, Loctite had been used on the metal clevis thread: Loctite do make plastic-safe threadlocking compound (Loctite 425), however, it is cyanoacrylate.

It sounds like it missed out on a degreasing process, there was some sort of contamination in the area or simply a bad batch of paint. As Christopher says, contact the retailer, its there job to sort this out. There was a case some years ago when composite helicopter rotors were delaminating in flight. It turned out that there had been a mosquito problem in the factory and a pest controller had sprayed liberally insecticide around the plant one night between production shifts. This had settled on the part-made rotor blades and acted as a release agent, preventing the layers from bonding properly.

All two part epoxies will benefit from post-curing for 12 hours at 60°C+ to raise the glass transition temperature (the temperature at which it will go soft again), If its not practical to put it in an oven or hot box, then in the attic under the South facing roof is a good alternative. Often the stickiness felt is uncured epoxy, from not getting the adhesive/hardener ratio spot on. As epoxies rely on the two parts having a chemical reaction, if there is more than one part than the other, the surplus will have nothing to react with and remain uncured. Precision weighing scales available cheaply on ebay that will measure to 0.1g make getting the right proportions a lot easier than in the past. Regarding post-curing, I was responsible for qualifying an epoxy glass heatshield for the fuel metering unit on a Rolls-Royce Trent engine. Not only was it glass fibre, it also had a silver-loaded epoxy coating on the inside. One test was 250°C for 5 hours to simulate a burst bleed air duct. We were expecting the heatshield to be quite badly damaged on the outside by this. In the event, it came out better in all respects than it went in. It was stronger and had better conductivity through the silver-loaded epoxy.

I'm a few years late to the game on the avoidance manouvre, but having just attended a lecture by the local area's BMFA reps, and been told about this, it raised a few questions for me. The scenario described by the BMFA reps was of an unexpected hazard on the runway. This could be child on a bicycle, a horse rider, or a fellow modeller who set out to retrieve his model without checking that no one was landing (accidents are always a case of the holes in the Swiss cheese lining up, so we've got to assume that all the precautions we usually take to avoid any of these scenarios from occurring, have already failed). What really concerned me, was the idea that the pilot, with a hazard out of sight to him, might slam the throttle open, thus making a bad situation potentially much worse. A horse or a small child on bicycle could be alarmed by the sudden noise, and with the motor or engine will have gone from very low rpm to potentially full thottle, the propeller is suddenly a whole lot more hazardous if it were to contact anything. Another issue is, in a real world scenario, at the end of a flight, an engine low on fuel could lean cut if suddenly pushed to full throttle, or an electric model with a largely depleted battery may not give the thrust expected, so the manoeuvre also needs to put the model where it will do minimal damage if it did dead stick, or just not climb. Reading the actual wording of the 'B' test document, it turns out that the story is rather different. It does describe 'turning to an angle of 30 to 45 degrees away from the flight line' and taking the model back up to circuit height 'with appropriate use of the throttle to avoid stalling'. So it is not a case of 'throttle to the wall, yank and bank', as some may have inferred. If the avoidance manoeuvre is really to demonstrate a safe recovery from a potential collision with someone, or something, on the ground, it is imperative that the throttle is only opened when the pilot can clearly see that the area in front of their model is unobstructed. Assuming the pilot keeps their eyes on the model throughout the manoeuvre, this must be after the turn is completed as the model is now heading away from them and the pilt can see ahead of the model. John Farley, the Harrier test pilot, said that practicing for emergencies works only if your actions in the practice are identical to your actions when it happens for real. If the avoidance manoeuvre is going to be of real benefit, instructors need to ensure their pupils fly the manoeuvre correctly and understand the risk their model and their actions pose, and how the sequence of their actions mitigates this - Turn, Look, Power.

I use the FS-i6 with the FS-ia6b receiver. I find it very good, although the comment about the sticks being a bit short it valid. If you are going to use it as a buddy box master transmitter, do yourself a favour and swap the top left two position switch for a sprung one or this one from Midland Helicopters. You won't have time to think about which position a switch should be in when taking control. The switches are also available on Aliexpress.

I went to a talk by Per Lindstand once in which he described his Atlantic Crossing with Richard Branson in the Virgin Atlantic Flyer. He said the air inside the 2.3 million cubic foot capacity balloon weighed the same as a Chieftain tank (around 70 tons). Even a small balloon can knock over 'buildings'...

When I was in the Scouts we made hot air balloons from tissue with either a 1/4" square balsa ring at the base. The balloon envelope was about 7ft tall and 5ft diameter at its widest point. Heat was provided by a paraffin-fired Primus stove prior to launch. Performance was marginal. On a winter's day the balloon would ascent about 150ft at best. We also made our own balloons out of dry cleaner's bags with wire base. Crossed wires held a piece of meths-soaked cotton wool at the centre of the envelope mouth. Again, performance was marginal. Too much sellotape sealing the hole where the coat hanger was meant to go in its previous life was enough to prevent flight. My suggestion would be to first make a balloon which will fly without carrying the burner, then start ballasting it up to determine what weight can be carried. Once you know the maximum, then you know the target weight your burner and fuel must not exceed. Blue flames burn much hotter than yellow ones, so try and get a plumber's or chef's gas torch to get the envelope temperature as high as possible. 'Jet flame' windproof lighters are available cheaply which give you a self contained gas cylinder and burner assembly at very low weight for flight, once the envelope is buoyant. Some sort of shroud around any flame you use is a good idea to prevent the envelope accidentally getting in the flame (speaking from experience of watching hours of work go up in smoke...).

There are a total of eight Veco 19 engine tests on the Sceptreflight Database (3/4 of the way down the list in the righthand column). The ones I have looked at suggest 30% castor oil for running in and 25% thereafter. NItromethane content seems to be anything between 0 and 25%, which may have had more to do with its availability at the time than what the engine prefers.

My work laptop pushed me into an upgrade from Windows 10 to Windows 11, The laptop was then unable to see the network, despite our resident IT man spending an hour working on it. Eventually I uninstalled the updated network driver and I had the network again. In a similar vein, the Ebay app on my phone has updated and is now demanding ios 17, whereas my phone won't go beyond ios 15, so I now have to use Ebay on the browser, not the app. 😖

If you hear the 633 Squadron theme tune, then the parcel is at your front door, however the drone has brought the house down on top of it...

The only model that I can find with that combination of wing tip shape, dorsal fin, rear 'window' and bolted on wing is the Super Flying Model Tri 40 II. They appear to have been available as a kit and an 'almost ready to fly' (ARTF), which may explain the non-standard colour scheme. It even has that wing joiner with the slot in it , although if you look at the RIpmax instructions for the ARTF, the tip appears to have been redisgned between the cover photo and the body of the building instructions. Kit instructions for the Tri-40 II ARTF Instructions for the Tri-40 II

A couple of MATS A aerial targets up for sale

payneib, you forgot to add that their solution to all such situations is, 'Buy more guns'. 😀

Bonzo Moon, that is certainly an impressive achievement, not least for being able to achieve continuous flight within the space available and without hitting obstructions. There are a few people who would have taken exception to your claim of the first quadplane though. Matthew Bacon Sellers Jr. built the first successful quadraplane in 1908, capable of flying on 5hp after development. Frederick Koolhoven, the famous Dutch designer, Designed the Armstrong Whitworth FK10 fighter in 1916. Noel Pemberton Billing the Supermarine founder and Member of Parliment designed the incongruous Zeppelin hunter, the Supermarine Nighthawk, which just goes to prove that every aircraft in Dastardly and Muttley has existed for real at some point.

There's always the possibility that the constituent parts of one of the ingredients has been changed, usually for environmental reasons, and not relayed on to the customer (fuel blender in this case). I've come across this sort of thing a number of times in the the day job. The other possibilty is that some fluid that was around or being used by the Richard when cleaning or rebuilding the engine had an effect. Thread locking fluids, for example, can casue all sorts of damage to plastic and rubber parts.