Shaunie

Make sure the pack is securely mounted wrapped in foam. If you make a separate mounting plate be sure it is well braced because if it starts to resonate then you are back to square one. Is it possible to bring the ignition equipment forward too? Shaunie.

Sorry to hear this Ted. It's something I live in fear of. Possessions can be replaced it items of sentimental value that hurt the most when they are lost. Still, at least you'll get a full redecorate . So glad the alarm worked otherwise you may well not have survived. Good to know you are both ok. Like others I would like to know the cause, please let us know in due course. Shaunie.

Martin, Agreed the dip is very low. But what happens in continuous high current overcharging? I haven't seen Manufacturers graphs for that. I am not saying a problem will occur only that it may occur. My statement about terminating promptly was only applicable to fast charging and not trickle charging, in this case it only shortens their life, thermal runaway will not occur. Perhaps I should have put it in two separate sentences, sorry, clumsy grammar/poor punctuation. Nevertheless it was something the manufacturers put in their data sheets and so is worth knowing. Shaunie.

You just need to think about the charging methods used for different battery chemistries. Lead acids. Float charge to a finite voltage. Current tapers towards zero, charging can be continued indefinitely with no detrimental effects as long as the float charge voltage is not exceeded. Suitable for parallel operation. Lithium Polymer. Float charge to a finite voltage. Current tapers towards zero, Charging can be continued indefinitely with no detrimental effects as long as the float charge voltage is not exceeded. Suitable for parallel operation. Nickel Cadmium/ Nickel Metal hydride. Constant current charge at either 1/10C max for 16Hrs or fast charge until temperature rise or negative Delta V signifies charge must be terminated. If charging is not terminated promptly then cell destruction is most likely to occur. As the cell reaches full charge the terminal voltage actually dips slightly. Float charging cannot be used as the cell will continue to draw current until destruction. Not suitable for parallel operation. As Supernash says "A fully charged nimh pack in 100% working order, hot off the charger, would be at great risk of starting to be charged further by a second pack connected in parallel. Nothing has to fail to get into this situation." The warm fully charged pack will have a lower terminal voltage than a the not so freshly charged one and a circulating current will occur. Likewise with two cells permanently in parallel one may peak before the other, it's voltage will dip and a strong circulating current will pass between the cells, with one getting hotter and hotter until it self destructs. In short it's not the internal resistance that is the problem it is the voltage characteristic. On balance I would prefer to see diodes, when we look at the complexity of modern radio installations are two diodes and four joints really that much of a problem? I think however, that normal length switch harnesses using a switch for each pack would probably be Ok. as the circuit resistance between the packs would be sufficient to limit any circulating currents. Shaunie. Edited By Shaunie on 01/08/2016 12:57:30

PatMc, let's agree to disagree then. Maybe things have changed but it was considered industry best practice when I started in electronics almost 40 years ago and I see no real reason to change my view. Remember that failing to follow best practice does not automatically cause disaster, it just means that when boundary conditions occur what you may have got away with you may not get away with. What I can't understand is why you are so dead set against a pair of diodes, if you use Schottkys then the voltage drop is very small, you have little to lose and it may just make a difference. I am talking Rx packs here not massively high current applications like flight packs of yore where any voltage drops were a significant problem. As far as the OP is concerned, separate packs separate switches, use diodes if you wish. Shaunie.

Sorry PatMc, but LiPo characteristics are very different and of course can be happily connected in parallel. You seem to have a very strong opinion on this subject, I can only suggest you pull up some manufacturer data sheets and take a look. In the interests of this being a friendly forum, I will often back down, in this case I stand by my previous post. Shaunie.

In electronics circles it is generally frowned upon to connect Nimhs or NiCds in parallel. Their low internal resistance and negative voltage characteristic at full charge can cause thermal runaway situations. Check cell manufacturers data sheets as they have warnings about this. So saying, this is really only a problem if cells are paralleled at the pack. I feel that if packs are connected through their own individual switches then the lead resistance will give sufficient isolation between the packs to avoid problems, nevertheless I would not be happy to see two packs permanently connected in parallel. Of course if a cell was to fail short circuit then there would be a very large circulating current that could cause burn damage to the wiring. Diodes would prevent this admittedly very unlikely event causing a problem. So basically, the advice to use diodes was given by someone who read the cell manufacturers data and understood it. Shaunie.

I was given a DX6I and was quite disconcerted to find a fixed battery holder. I witnessed the demise of a friends plane many, many years ago through rechargeable cells in a Futaba Tx, power went off, plane went in. Embarrassingly a conversation just a couple of days before went like this:- "Don't use NiCads in spring holders". "Why not, I've never had any problems". "Well you will have somewhen". Oops! I've got rechargeables in the DX6I but I have put Electrolube contact treatment on the battery poles. Shaunie.

Impressed, you've got the tyre treads the right way round, not many people know which way they should face. Are you a country boy? Shaunie.

I'm left handed mode 2 but launch right handed. On the downside there are many occasions I've had to slap the stick with my right hand to jerk the nose up, on the upside it's easy to open the throttle just before you throw. Keep meaning to learn a left-handed throw and how to open the throttle with my chin. I'll get round to it one day! Shaunie.

When you place too much trust in autonomous technology http://www.theverge.com/2016/6/30/12072408/tesla-autopilot-car-crash-death-autonomous-model-s Shaun. Edited By Shaunie on 27/07/2016 11:24:46 Edited By Shaunie on 27/07/2016 11:25:33 Linking seems to be messing me about today  Edited By Shaunie on 27/07/2016 11:26:55

Too quiet? Had a hearing test recently 😎. Shaunie.

In many cases boiling water is sufficient, take care not to get new bearings wet of course! Shaunie.

What about a triangular fillet between the top deck of the fuselage and the fin? I always feel that there is a stress raiser right where your fin broke and a fillet helps to spread the load a bit. Shaunie..

Part of the problem for us modellers is that we cannot see or measure AoA directly. As a result it is common for modellers to estimate AoA with respect to the horizon and not the path of the plane, if the aircraft is sinking as on finals then AoA is actually much higher than the pilot perceives it. Would that be right BEB? Like someone already posted (sorry forgot your name, it was a couple of pages ago) I liked fast passes and sharp pulls into the vertical with a Seagull Edge540 68", overdid it one day and practically got a snap roll, luckily it wasn't a ground level job and some nifty stick twiddling got me out of trouble, no bin bag required thankfully. Definite high speed stall. Unfortunately I tend to fly fun fliers a lot and they develop bad habits, as finding a defined stall can be extremely difficult on occasion. Shaunie..

Something I would add is to only use a chainsaw if the wood is of a decent length, cutting an eighteen inch length into two nine inch pieces can be tricky as it is difficult to hold. You may get away with a 12 or 14 inch saw, my Stihl only has a 14 inch bar which is plenty for a general purpose and logging saw. Shaunie.

I think the least blade exposure possible is the best for two reasons. 1. The blade is not crossing the wood at right angles so it should give a better finish with less break out at the bottom. 2. In safety terms any contact with the blade and your fingers is a bad thing but if things go wrong then less blade exposure could make a difference between a nasty nip and an amputation. Shaunie.