Chris Bott - Moderator

That will be good to know how well that works. To add head tracking do you connect into the Tx buddy socket and only buddy up 2 channels? Leaving the 3 or 4 main control channels un-buddied to fly the plane with?? Does that question make sense? Is that what split buddy means?

Nick The Head Tracker I saw that works with a buddy is here Cheers Chris

in for a penny....

On one of the sites I'm sure I've seen a headtracker which also allows a buddy lead to still be plugged in??

I've found that last few posts here very interesting, I got up to B (ish) standard 18 months ago but didn't manage to take the test. Since then, the weather has conspired, such that I am well out of practice. My biggest issue was always the slow roles and yes I'm on Mode 2. The examiners in my club are all mode 1 and don't seem to understand my difficulties at all. They however are not always so clever at stuff that takes co-ordination of elevator and rudder together such as the stall turn which I seem to find easy. I was out today and my rolls are getting much better, I seemed to be correcting all the way round without thinking. It's the "without thinking" that seems to be the key, and this can only come with practice and more practice. Practicing other non B stuff like flat rudder turns keeping the wings level, and knife edge, using elevator as rudder, also seem to be helping.

I've seen that one live at our funfly. It sounds great when John runs the startup sequence and the Merlin splutters into action just as he moves the throttle to a tickover position. He taxi's out with a fast tickover and its great when he opens up to full throttle and takes off, big grins all round

I tried some equipment out for a slightly different application and found that using 2.4Ghz in both gave me a different problem. The model control was fine, but the 2.4Ghz pictures coming back were rendered unusable by the transmission from my RC transmitter.

Is that why I enjoyed my Diesels so much?? LOL (Ether - the "active" constituent of model diesel fuel) There are already quite a number of sound equipped large electric models on the display circuit. Throttle is indeed slaved, and an authentic startup sound is included, before the sound revs with the throttle setting. e.g. http://www.youtube.com/watch?v=9Qlz-fniK1Y

Scott that's really interesting, when will you have details and prices?? I'm quite interested in doing this but so far prices have been too high, amplifiers too inefficient (and get hot!) and speakers too heavy. Not that I want much

The AR500 is a very interesting development. It only has a single "box" i.e. no satellite receiver. But it is marketed as a Full Range receiver. This appears to be achieved by having a normal short aerial sticking out one side, while the other is on a cable (maybe 6" long??) So it can be positioned away from and at 90deg to the short one. http://www.spektrumrc.com/Products/Gallery.aspx?ProdID=SPM5500&Index=6 Is this the layout of full range Rx's to come? It does also appear to have a satellite socket, but that just be 'cos they have used the 6200 case.

Arrgh, now I wish I hadn't returned and read this thread as this ground keeps being gone over and over. I refer to the 6V is better than 5V and UBEC debate. A model carrying 5 or 6 servos will need a Rx supply that can supply a good amount of current. Also note: small servos tend to take more current than standard sized ones. A BEC in an ESC or an external UBEC will be designed to supply a certain amount of current, and up to that figure will hold its voltage steady. UBEC's generally have higher current figures than built in BEC's in ESC's. However if you pull more current than the unit is rated for, then it will heat up. If it continues to heat, it will self protect and shut down. Until it cools again. The heating can build up through a number of flights even. So it may not even seem a problem on the first flight. Using a 6V UBEC will move servos a little quicker than a 5V one and the servos will pull a little more current from a 6V one. So it could be, that using a 6V UBEC might be worse than using a 5V one. It's more complicated than this. But my point is, that the only important thing is to have a supply that can provide sufficient current and not overheat. Headroom really doesn't help if the chip shuts down on overtemp. (Switching UBEC's will produce much less heat than linear ones. But I'm not sure many state which type they are in the spec.)

Eric I miss the smell of ether too, but I never detect it at all when I visit an IC session. I use built in quick recharge batteries all the time and fly exactly the same IC models as the IC guys (mine are electric). Some with much more power. Some have longer duration and some shorter. I would like some noise, but all the other advantages outweigh this for me. Such as being able to fly at any time its daylight, instead of just during our limited IC sessions. Indeed I had (till a glitch between the ears killed it) a 50 Sized ARTF aerobat which I built for quick change between IC and Electric. This could be done in 2 minutes. At the end of an IC session I would convert to electrics. There was no comparison, electric power in this model was far superior. (Irvine53 IC / 6S A123 electric) This is probably as close as I'd like to get to an IC powered electric. Although I cant fault the thinking about reliable twins. OOH, I have charged my electric models from a generator, does that count???

Shan, OPTO ESCs dont have BECs so you shouldnt need to cut the red. To test for this, plug one ESC into a RX, power it from the motor battery and see if the receiver fires up. If it does then there is a BEC, if it doesn't, there isn't

That sounds like good advice for all of us

Most of the smoke is kept in the speed controller, and some is in the motor, trust me, I've seen it come out of both. Smoke release is mostly caused by too big a prop and not knowing. The big secret is to use a meter of some sort, that way you know for certain the following things:- 1, The setup is carrying LESS current than the motor, ESC and battery are rated for. (at full throttle) 2, The setup is NOT pulling the battery voltage below a safe level for the battery. Say - 3V per cell for a LiPo (at full throttle) 3, Full throttle power is sufficient to fly the model. These days with highly efficient motors. 100W per lb is pretty sprightly. This is where it gets difficult to recommend a setup for a particular plane. Experienced electric flyers will either use a setup tried and tested previously, or have a good idea what to try, but then experiment and try different props to get the readings right. Sometimes even having to buy a second motor to get it right.

No probs Paul. I tend to bore people preaching about these cells They do have some disadvantages mind you:- 1 Heavier and bulkier than 2200 LiPos 2 Only really one size available (there is a 1100mAh but not widely available) 3 Seem more expensive until you weigh up total lifetime cost But the safety (no charge fires etc) and robustness, keep me coming back for more. I only use Lipos on small planes now. They are ideal in 6S form for 40-50 size planes. I flew a lot of planes on this particular pack and one other which still seems OK. Charging in 10 mins while flying the other. Nowadays I seem to be building them into the models. They do need a balance every now and again, but I do that after a session, at home, not at the field.

That's an excellent idea John. Full marks for that one. I think I'd want to calibrate anything like that if I made one, and this would mean the expense of an ammeter anyway... Another easy way is to purchase a purpose built wattmeter. This one here is about £20 with postage and even has a built in servo tester so you can operate your speed controller without any radio gear. http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=6553

pls chuck my name in the hat

And indeed motor too if you have a 30 amp motor and yr drawing 29 amps....

Having measured thes things in flight, it is surprising just how much the system does "unload" in the air. Its hard to put a figure on because every model is different And the graphs I have, don't show which way the model was pointing when full power was in use (usually upwards!) The reading is very useful though to prove that in worst case situation (except going backwards or motor stalled) the motor battery and ESC are all working inside safe limits. What surprised me more than the unloading however, is the average current used over a whole flight. Unless you have to hold full throttle for the whole flight, then the average current is always less than full power current (obviously), but in my experience it is much less that full power current. This is due to using full power for impressive verticals, then using the models inertia or height to complete down and horizontal parts of a manoeuvre. It is the average current that determines flight time. Without on board measurement, another way to work out max flight time is to fly for a few minutes, land and charge. Check how much charge you put back in, and you can work out how much more flying time you could have. On a typical Wot4 flight (not mine this time) I have a graph showing: PACK AMPS Min=0.0 Max=44.28 Ave =15.87 POWER Min=0.0 Max=850.18 Ave=281.31 The Max would have been stationary on the grass just as throttle is whacked to full and the model starts to move. To conclude, static measurements are very important, but not the whole picture.

Today I flew a 6S pack of A123's and the flight didn't last as long as I expected. To cut a long story short, I actually seem to have a couple of dieing cells. A pack charge took 1020mAh and after a deadstick landing I would expect 2200mAh. So I knew something was up. So on to a balance charge and it took hours because it went to a very low charge rate because most cells were full. A few discharges and balances later, it is clear that one cell is tired and another on its way. Well I can't complain. This is the pack that started all the fuss over 2.5 years ago. It has been well used and well abused ever since. Most charges at over 10A with little or no balances for the first 12 months. It's been discharges at 120A. On at least 2 occasions the whole pack has been down to zero volts. In all that time it has provided hundreds of powerful, reliable flights I haven't taken the heatshrink off yet, it will be interesting to see if the cells were those that have been soldered to directly, after a crash dented them and ripped the tags off. Well there we are, they are not completely indestructible! and do have a lifespan. However to get the same amount of flying, I believe would have cost multiple LiPo's even if looked after well. And If I'd subjected LiPo's to the abuse these have had, then that would have cost me dozens of LiPo's So in the right application, these have proved very cost effective indeed.

Well said Ian I believe that is what most of us are thinking, but maybe not in such a clear manner.

Guys haven't we gone just a tad off topic here? I thought this topic was about Shauns two losses of control.

Doug we had/have something very similar at our field. On odd occasions a tiny part of the sky has glitches in it, they were always very brief so unnerving rather than dangerous. Thankfully they seem to be there less and less often these days. In fact I don't remember a mention this year at all. But they never chased a model right down to the ground with total loss of control. The absolute fix for them last year was definitely 2.4Ghz. On the odd day we did suffer, we managed to pretty much prove that 2.4Ghz cured our problem. Whatever it was.

I agree UBEC is best these days, I did used to have glitch issues with them myself. I've only just spotted this thread and have skimmed through so sorry if I'm repeating something. It seems to me that Shauns crash could have been caused by an overheating BEC?? It could have got warm on one flight, hot on a second and eventually too hot and it shut down. This would give no volts to Rx, ESC would shut down power to motor and there would be no control. It's important that the BEC will handle all the servos on board. Here's where I assume a lot - did the model have small servos? they usually take more current that standard ones. did the model have many servos? I have in the past connected up an external BEC (early UBEC, linear type) and sat waggling sticks for 10 mins. Eventually the BEC overheated and shut down. 1/2 hour later it was fine again, it had cooled.