Peter Christy

The receivers aren't the issue. Its the servos. JR servos burn out quite quickly above 6V, especially if worked hard. The general consensus is that Futaba servos are more tolerant, but any servo not rated for higher voltage will have its life significantly shortened by running it on an excessively high voltage. LiFe generally cells are better than LiPo or LiIon cells, as they are 3.3V per cell (6.6 for 2S Vs 7.X for LiPo/LiIon). They also don't have a tendency to burst into flames if mischarged like LiPos, making them safer to charge in situ. You really need to find out what your servos are rated to. -- Pete

Ooops! Just realised I posted that a while ago! Sorry for the repeat! -- Pete

Never mind "Two Old Boys", how about "Three Young Chicks"? I wish I could play like that! -- Pete

The throttle on a typical glow motor is very non-linear. With the barrel half open, its probably producing around 80% of its max power. As Don and others have implied, I usually offset the linkages to provide finer adjustment at the tickover end, and correspondingly coarser control at the top end, where fine adjustment is not needed.

Reminds me of the time I was working for a major news broadcaster, here in the UK. I was the shift supervisor in the videotape department that night which was around the time the miner's strike ended, and it was about 15 minutes before on-air. A senior journalist from the newsroom burst in shouting "We may have to change the top of the show!". This caused me some concern, as for once, we had everything ready to roll early. Now bear with me! You have to read the next bit out loud to get the drift: Me: "What's up?" Journo: "The Home Secretary has been caught with a minor!" Me: "A MINER?!?" Journo: "NO!! NO!! A MINOR!!!" As all the news had been about for months was the miner's strike, it was an easy mistake to make! In the event, the fact checking didn't stand the story up. To run an accusation like that about a senior government minister requires at least two verifiable sources. In the event, both were traced back to a common source, and the story was dropped. But it caused much hilarity, the thought of the Home Secretary being caught in flagrente with a coal covered individual with a lamp on his head bringing tears to the eyes of the normally stoical techies....! -- Pete

Thanks to Phil for a very clear explanation! To amplify my comments on venting and "black wire corrosion": The vents on a pen-cell (or similar) are at the positive end of the cell. The vented gas has a slight, but noticeable, positive charge. This attracts it to the negative end of the battery. The gas itself is relatively harmless - to the battery, anyway. The problem arises if the air is at all damp, which it frequently is in the UK. When the gas is absorbed into water, you end up with a very caustic solution, which will eat away the wiring quite quickly. This is why black wire corrosion was most common during the wet winter months, charging in damp sheds, garages, etc. Those who kept and charged their models in the house seemed to suffer from it less. It actually didn't matter what colour the wire was, either. Its just that black was the traditional colour for negative leads. This was all explained to me decades ago by the representative of one of the battery companies at the height of the black wire corrosion scare. The problem has all but disappeared since peak detect chargers became common place. Trickle charging still has its place, as it does balance the cells. However, I stand by my point that it is not something to do on a regular basis.

Trickle charging NiMHs (or NiCADS) is OK occasionally, but not something to do regularly. It will inevitably lead to the cells being over-charged, venting gas and drying out the electrolyte inside. This is not good! It was the introduction of peak-detect chargers that led to the virtual disappearance of "black wire corrosion", which was primarily caused by the cells venting caustic gas when trickle charged regularly. I normally discharge my packs after the winter layoff and give them a trickle charge to balance them. I then do a capacity check on them, and thereafter just peak detect charge them until the following winter. Most modern chargers will display how much charge the cells have taken, and as long as this is in line with their use since the last charge, then you should be good to go. -- Pete

I had to replace one in an old JR transmitter a while ago. I did manage to solder to the cell without damaging it, but it is tricky. There wouldn't have been room between the PC board and the case to fit a holder, which is why (I assume) JR soldered them in directly. Thanks to Jim (above) for the pointer to Amazon! I must admit that that never occurred to me! I had tried all the usual suppliers to no avail! -- Pete

And please don't, without some expert guidance! Helicopters are not easy to get to grips with, and can get away from you VERY quickly! Find a local club. If they don't have a heli expert, they can probably point you to another club that has. As other have said, its probably the lithium button cell on your radio. For some reason, JR had a habit of soldering them to the board rather than use a clip in holder. Since cells with solder tags are like rocking horse manure, this may involve some delicate soldering work. Like Andy and Jim above, I would recommend the Model Radio Workshop, which has an excellent reputation.

I think the point the OP was making was not the absolute price of fuel, but the fact that it appears to have suddenly increased dramatically for no obvious reason. -- Pete

I suspect this is the problem you get when there is a virtual monopoly in the supply chain. Not that long ago, there were two major brands, now there is only one. Yes, I know that there are other smaller suppliers, but these aren't what the majority of (remaining!) model shops stock. Further, with the declining use of i/c engines, there is little incentive for another supplier to enter the market. In days of yore, we used to mix our own, but thanks to government legislation, its almost impossible to buy nitromethane any more. Luckily, a lot of older European engines are quite happy on straight fuel....! -- Pete

I should have added that I've just re-acquired that Morley! I sold it - along with a 2c body (only one set of mechanics) - to a clubmate, who left it in the attic. He is now very ill, and a mutual friend negotiated its return. Its awaiting its turn on the building board for restoration to flying condition - and probably conversion to electric!

The Morley flew with a Sprengbrook "Red Box" set - you can see it in the non-flying picture, though not the colour! No gyro (not invented at the time) or collective pitch, and just a plain four channel radio. The engine was an OS Max 40, which is still flying in a fixed wing sport model!