Peter Christy
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Everything posted by Peter Christy
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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
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Ooops! Just realised I posted that a while ago! Sorry for the repeat! -- Pete
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Never mind "Two Old Boys", how about "Three Young Chicks"? I wish I could play like that! -- Pete
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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.
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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
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Spektrum 2.4 4.8v RX battery?
Peter Christy replied to martin collins 1's topic in All Things Model Flying
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. -
Spektrum 2.4 4.8v RX battery?
Peter Christy replied to martin collins 1's topic in All Things Model Flying
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
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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.
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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
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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
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Your Younger Self and Early Models
Peter Christy replied to Futura57's topic in All Things Model Flying
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! -
Your Younger Self and Early Models
Peter Christy replied to Futura57's topic in All Things Model Flying
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! -
Your Younger Self and Early Models
Peter Christy replied to Futura57's topic in All Things Model Flying
My first successful (briefly!) RC Model - Mini-Robot, circa 1965: My first low-wing aerobatic model - "Tornado" (locally produce Taurus clone) c.1969: My first heli - Morley 2B circa 1974: Learning to fly it on Croxley Moor (Watford): Happy days! 😁 -
Making Old Timers More "Flyable"?
Peter Christy replied to payneib's topic in General Vintage R/C Chatter
Robin: I run my ASP on 5% nitro, pure synthetic (no castor). I don't normally stock 5%, as I use 16% for my OS powered helis, and straight for my European engines, ancient and modern. I make 5% by mixing two parts straight with on part 16%, which is close enough! Having said that, with the demise of Model Technics, straight fuel with pure synthetic is getting harder to get hold of. I've bought a gallon of Laser 5, which like MT Bekra, is pure synthetic. I may have to switch my "straight" engines over to that. (Mick Wilshere will be spinning in his grave! 🤣 ) I've always used an electric start on it, without problems. The rocker broke in flight, and the engine just stopped! It tends to tighten up if run at full throttle for too long. Just Engines reckon it isn't run in yet (now four or five years old)! Compression is generally quite good, but it is a bit gutless.. P.S. One last thought: Have you stripped the carb? If it runs on a prime, it could be fuel starvation. It is difficult to suck mixture up that inlet pipe. Mine runs on exhaust pressure, and a finger over the exhaust while on the electric start prior to attaching the glow should get fuel into the carb. -- Pete -
Making Old Timers More "Flyable"?
Peter Christy replied to payneib's topic in General Vintage R/C Chatter
Another model the OP might want to consider is the Astro Hog from 1958, generally acknowledged to be the first practical, low-wing aerobatic model. It certainly set the benchmark for those that followed it! I don't have a picture, alas, but the plans are on Outerzone, with accompanying pix. Glad you liked it! At first, I flew it on a Grundig reed set, converted to 2.4 GHz, but it tends to swing a bit on takes off, and needs you to be quick on the rudder! Much easier with proportional radio! Its a little bit under powered with the ASP 30 4-stroke, and needs a decent take-off run and short grass. I'm not terribly impressed with the ASP. It doesn't have a smuch get up and go as my OS 20 FS. I wish OS still made the 28 FS...! The ASP broke a rocker a while back, and while it was away being repaired, I fitted a 25 2-stroke, which made it a LOT livelier - but not quite in keeping with its vintage! 😁 It also emptied the rather small tank quite quickly! The ASP is now back in place, and peace and tranquillity has been restored! -- Pete -
Making Old Timers More "Flyable"?
Peter Christy replied to payneib's topic in General Vintage R/C Chatter
You might also want to consider a Frog Jackdaw - the often forgotten competitor to the Super 60, and a more lively model. Although designed for single-channel (rudder only), the plans also showed up to full-house controls (aileron and elevator). It is around 60" span, so similar size to the Super 60. Its not as "floaty" as a Super (or Junior) 60 and is certainly capable of loops and rolls. Originally designed for a 3.5cc diesel, "back in the day" many were fitted with Merco 35s, which gave them sprightly performance. Mine flies adequately on an ASP30 4-stroke. An electric conversion should be relatively simple, as there is a nice big hatch for the fuel tank. Mine has full-house controls, and has flown on "giga-ized" reeds: Plans available on Outerzone. -- Pete -
Oh yes! I got in the habit of fitting locking nuts on my comp screws decades ago. IIRC AM15s used a 4BA thread, so it was quite possible to solder a bit of piano wire across a standard 4BA screw and use that! (Much cheaper and quicker than getting a manufacturers replacement!) Can't remember what the PAW 1.49s used, but by the time I got them, I'd learned my lesson and fitted locking nuts! 😁 -- Pete
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Brian Taylor has passed away.
Peter Christy replied to martin collins 1's topic in All Things Model Flying
Very sad to hear this. Around 1967-8, as a teenager, I used to cycle out to Merryfield from Taunton, single-channel model in a duffle-bag on my back, to fly with the guys there. Despite them all flying expensive (to me!) models, they always made time for me to lob my Cox .049 s/c model off and have a few minutes solo airtime. Even then, before he became well known, it was clear that Brian was an outstanding pilot. As Tim (above) has said, proportional radios were so new that most club pilots were still on either single-channel or reeds. Brian had a scale Japanese dive-bomber (a Kawasaki something or other IIRC) which he flew with great gusto. His low level high-speed passes were something to see. Merryfield was open to the public back then, and the model club flew at one end of the runway. A drag racing club operated at the other end, and one week-end a particularly obnoxious character in a Daimler Dart decided to do some high speed runs into our end of the runway. I will never forget the moment when, travelling at very high speed, he looked out of his window to see the Kawasaki dive bomber overtaking him at a height of about two or three feet above the runway! Brian had dived from quite a height to get that much speed up, and the Dart was probably slowing down as the end of the runway approached, but it must nonetheless have given him quite a shock! He got another shock a few moments later, when another club member (who had better remain anonymous, as he's still active!) dropped a couple of flour bombs in front of him from the club's toffee bomber! He fled back down the runway, never to be seen again! Happy days! I believe that Brian had to give up flying due to failing eye-sight in recent years, though this was only gleaned second or third hand from another pilot from those days, that I happened to run into. Even back in the 60's he wore quite thick tinted glasses, so it sounds about right. RIP Brian, and thanks for the memories! -- Pete