Peter Christy

I've got an original OS20 FS in my collection. I've owned it from new, and used it in a Flair Attila with reduced dihedral and ailerons. The power was quite adequate swinging a 10x5 prop, and it both looked and sounded like a WW1 aircraft. I mounted it inverted, but had to move the tank to the floor of the fuselage to avoid flooding. Once that was done, I never had any problems with starting it inverted, though I was always careful to check it for hydraulic locks before applying the starter! The original Attila bit the dust some years ago when I deliberately crashed the model to prevent it drifting over the nearby railway lines. The radio had gone intermittent - later traced to mildew build up on the circuit board - and rather than risk it ending up on the tracks, or worse, I ditched it. I have another Attila kit awaiting its turn on the building board, and the 20FS will be going in that - eventually....! (So many projects, so little time....!) -- Pete

Nothing wrong with 35 MHz (or indeed 27 MHz before it) at all. We used both very reliably for decades! The only issue now is that no new equipment seems to be manufactured for those bands, and a lot of the gear is getting quite old. As long as it has been stored correctly, the only thing that should need changing is the batteries. We stopped using 27 MHz when CB radio arrived and swamped the band. I can't remember the last time I heard any CB activity on 27 MHz where I live, though it may be different near a busy motorway. 35 MHz was exclusive to model aircraft use in the UK. Both 27 MHz and 35 MHz did require some discipline amongst their users to avoid frequency clashes, but this was generally a minor inconvenience. No reason why a good quality 35 MHz set should not give years of useful service, if looked after.

Bear in mind that the original pack was probably only 5 or 600mAH, so the trickle charger will be designed for a a 10 hour charge rate for that pack - 50 or 60 mA. To recharge a fully flat 2000mAH NiMh pack on such a charger could take 40 hours! The charge rate should be shown on the charger, so its easy enough to work out - simply divide the pack capacity by the charge rate: 2000/50=40.

C'mon, mods! Where is that <GROAN> button we so desperately need? 😆

The local council used to have a big bonfire night on the beach every 5th of November. One of my school mates used to live on a farm and would turn up to the event with a sack of potatoes. All the parents would watch from the comfort of their cars, parked on the sea front facing the beach. Whilst the fireworks were ongoing, a gang of us would go along the line of cars shoving a spud up each exhaust..... Once the display was over, and everyone went to leave, the results were inevitable! Small Fords and Austins (remember them?) would probably stall, but Jags and Rovers would expel the spuds with explosive force - just like a giant spud gun - imperilling anyone in their way. No-one ever got hurt - aside from those unlucky enough to get caught, who usually received a sound paddling of the rear! But occasionally an older Ford or Austin would blow its exhaust off, and leave with it dragging on the floor...!

I remember us chucking lumps of sodium into dishes of water in chemistry classes. We were meant to cut them into small pieces first, without actually touching them. This isn't particularly easy, so guess who chucked an oversized lump in, and the size of the resulting explosion...! I also recall being given lectures on radioactivity in physics. We were all sent to the back of the lab, whilst the lecturer carefully opened flasks of different radioactive materials and scanned them with a geiger counter. After he finished the demo and carefully re-sealed the dangerous stuff away, we all returned to our seats - at which point the geiger counter went crazy! Someone in the front row was wearing a luminous watch - which was far more radioactive than any of the lab samples! And of course we travelled around in cars without seatbelts or crumple-zones. Makes you wonder how we ever managed to survive to adulthood! 🤣 -- Pete

Its not just electric models that suffer this problem! Many "new generation" i/c props are much more rigid than in days of yore. I was getting through APC and Master Airscrew props regularly on my Sharkface. Then I managed to get hold of some yellow Kavan props. I'm not sure if they are still manufactured, of if these were NOS, but I haven't broken one since! They are quite bendy, like the old school nylon props were. Probably not as efficient, but a Sharkie with a Cox .049 is quite "adequately" powered anyway, as are most electrics, so it efficiency is of little importance... -- Pete

Not at al! Your answer was technically correct, and a length of bell wire - about 6 ft - will have sufficient resistance to drop the voltage to a safe level. But IMHO, its not the optimum solution. Using a NiXX cell of suitable capacity and low enough internal resistance will do the job better, and be simpler. However, if a cylon battery is all you have, then your suggestion is fine. Use what you have, and upgrade when you can! 😁 -- Pete

A decent NiMh cell (D or sub-C) will never over drive a plug, and will also be more than enough for 2V plugs. You don't need yards of wire to drop the voltage, and they charge quicker than lead-acid cells. Win-win! The plug does not need to glow orange. It should be a nice cherry red. If you make it glow too brightly, it will start to shed the platinum coating, giving it a dull, grey look. That is when the engine starts to quit at low throttle settings! I can't remember the last time I had to change a plug because it was burned out or gone grey. I have been using NiMhs (and before that NiCads) for decades now, and would never go back to a lead-acid cell. I don't like power panels either, as it is far too easy to overdrive a plug with them and damage it. If you crank up the current, to clear a flooded plug, by the time you see the current rise as the plug clears, it is too late. The damage is done. If you supply a plug with the correct voltage, it will draw the current it needs - it is self regulating - and you will never inadvertently damage one. <Gets off soap-box!> 😉

Finally! Found some mild steel 2mm rod on Ebay! Should arrive by the week-end, but unfortunately I'll be away. I'll find out if its any good next week. Thanks to everyone for your suggestions! And in case anyone is wondering what its for, I'm making some electric conversions for MicroMold Lark helicopters, and need something to attach the motor mount (3D printed) to the chassis plate. Cheers, -- Pete

Thanks for all the suggestions, folks! I'll follow up on some of them. Just a couple of comments: 1) I've tried threading stainless steel spokes, and my die couldn't handle it. In any case, my understanding is that stainless is prone to cracking when bent and used in applications where vibration may be present. 2) Fully threaded rod: Might be OK, but I'm not sure how strong it would be after bending and subjected to vibration. Same problem as stainless, but might be OK if I can't get anything else. 3) Welding rod. That sounds promising! IIRC, Jim Morley used it to make the tail booms on his Bell 47 models, so it can clearly tolerate vibration. If it can be threaded, that sounds like a good option. 4) I have seen some black cycle spokes, but it isn't clear if the metal underneath the coating is stainless or not. Might see if I can locate a sample from a local cycle shop. 5) Search the local village pond for a dumped bicycle or pram...! 🤣 If I find anything useful, I'll post a follow-up! Cheers, -- Pete

Does anyone know of a source of 2mm or 3mm metal rod? In days of yore, I used to use bicycle spokes, but these days they all seem to be stainless and can't be threaded. The 2mm rods sold by model shops may have a 2mm thread on them, but beyond the threaded area, they are only about 1.7mm and too small to make a 2mm thread! I'm trying to make a "U" shaped strap to mount something - a bit like we used to make for dustbin silencers in years gone by. Ideally 2mm, but 3mm if I have to. The rod must be bendable and thread-able. I can't even find wire coat hangers any longer! -- Pete

I use high-capacity sub-C NiMhs. An AA cell will never be able to supply enough oomph for a glow plug. A plug typically draws around 3 amps, and the internal resistance of an AA cell will pretty much guarantee it won't deliver that for more than a few seconds. sub-Cs are about the minimum for a decent glow, and I've never had an issue using them. I'm afraid you've been sold a pup!

The MT Bekra helicopter fuels used the castor-free Klotz. I haven't used anything else for years - even in 4-strokes! I still have a couple of gallons of 16% and a gallon of straight left, but sooner or later, I'm going to have to bite the bullet...! -- Pete