Peter Hawtin Posted November 2, 2008 Share Posted November 2, 2008 Guys, Last week I purchased two 5A regulators to work in parallel in my Sukhoi, but decided to see how well they worked on my Cougar fun fly.I had an 800 ma 2S pack through the 5a regulator and all seamed fine until the flight.Yes I know I should have done a full range check but as I had only changed the battery I just did a short 10Mtr check and all was well.The cougar got about 50 Ft off the end of the strip, then started Glitching like mad before loosing control and powering into the ground on virtual full throttle(it was glitching from low to full with no control).I collected the wreck and kicked myself for not doing a range check and went home assuming the RX had a major problem.On getting home I did a range check using my FG12 rather than the 9cap, and also swapped out the receiver, but the problem remained.I then went over in my mind what had changed since the last time I flew the cougar and the only change was the LiPo RX and reg.I disconnected the Regulator and plugged in a spare 6v RX pack, problem went away.I repeated the test with several other makes of receiver including a 9 channel PCM RX all had the same problem, the PCM RX managed about 10feet more before locking out.On each RX, I switched back to the 6v receiver battery pack and the problem went away.I called a local friend who had a higher current version of the same regulator, and we did the same test with exactly the same problem.At this time I wont give out the manufacturers name as I will be contacting them tomorrow to discuss compensation, but lets say its a UK company selling Chinese products.Has anyone else had problems with LiPo regulator with Futaba 35Mhz RX's? I will do some tests on my 2.4 RX to see how they work and add it here.If any of you are switching over to LiPo RX batteries, then use this as a warning and do a full range check before you fly.Peter Quote Link to comment Share on other sites More sharing options...
Peter Hawtin Posted November 2, 2008 Author Share Posted November 2, 2008 I have just repeated the test using the a 2.4 14 channel futaba RX with the TX on range check and there does not seem to be an issue. This problem seems to be with 35Mhz only, and so is almost certainly a problem of RF noise being generated by the Regulator. Peter Quote Link to comment Share on other sites More sharing options...
birdy Posted November 2, 2008 Share Posted November 2, 2008 Its a switching BEC, so it'll create a lot of interference I'm afraid. Try keeping it as far as you can away from the RX and its aerial, and try some ferrite rings on the lead to the rx. Hope you solve your problem eventually,birdy Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted November 2, 2008 Share Posted November 2, 2008 It sounds as if this is a switching reg Peter? Although far more efficient than linear regulators, most suppliers do warn of the potential for interference on 35Mhz stuff, and some of them come ready fitted with a large ferrite ring.Incidentally, I note you have fairly heavy duty rating there with 5a capable units - yet your supply battery is a measly 800m/a - something doesnt add up there Quote Link to comment Share on other sites More sharing options...
Peter Hawtin Posted November 2, 2008 Author Share Posted November 2, 2008 A bit late to solve the problem the model is destroyed. All electronic devices creat noise, but a correctly designed unit will be "tuned" for the situation it is supposed to work in. This says to me the design of the electronics is for 40 or 75Mhz but not 35Mhz, and this should be mentioned on the instructions. I realise we are all responcible for ensuring the model is airworthy, but this one slipped under my radar.Interesting you say it needs a ferrite ring, the more powerful version my friend came over with was fitted with a ring, but still had the same problems. Have you seen similar issues?Peter Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted November 2, 2008 Share Posted November 2, 2008 On 35Mhz - yes - but then I went totally Spekkified 2 years ago and never looked back. I now run stupidly long servo wires, noisy cheap ESc and motors, fix Rx's right on top of EScs etc etc.... never a single glitch - ever. Quote Link to comment Share on other sites More sharing options...
Peter Hawtin Posted November 2, 2008 Author Share Posted November 2, 2008 I went to Futaba, and have no issues with that, but there is no warning on the unit, about 35mhz. We shall see in the morning what the shop has to say.If not its name and shame time.Peter Quote Link to comment Share on other sites More sharing options...
Peter Hawtin Posted November 2, 2008 Author Share Posted November 2, 2008 Sorry missed your comment about the battery size.This was on a fun fly model, that has been running on a 5cell 600mah Met Hyd pack for the last 2 years, to keep the weight down. The LiPo pack was 20C capable, so more than up for the task of running the fun fly. I drain 8amps off one of these cells in a shock flyer, so 1-2 amps servo drain should be no problem. To test the reg on 2.4ghz I fitted it to my 27% sukhoi, and that has 6 large digitals, and it had no issue even when I stalled the elevator to simulate some flying load.A 5a regulator has a good safety margin.Peter Quote Link to comment Share on other sites More sharing options...
Always broke Posted November 2, 2008 Share Posted November 2, 2008 First of all sorry that you lost a model, I hate that happening to anyone.I had a lot of problems as well with some Regulators (which is one reason I do not use them) and ESC's and to think of it electric flight in general causing interference on 35meg.I know most of these were solvable with some work but it was so much easy-er to go the Specy route and solve all of them which it has and like Timbo I fit things in silly places long leads etc and have no problems whatsoever. I would think in your case the shop owner would ask Did you do a full range test. If not then its asking a bit much to expect them to do anything about it. Perhaps if you had done a full range test then you would have found this problem ,then you could have returned the Regulator and they would have sorted it out. We all know that when changing anything we should carry out a full set of pe-flight tests and a range test should be part of that. We are all guilty at some point of not doing that and sometimes we have to pay the price which it looks like you have in your case. Quote Link to comment Share on other sites More sharing options...
Peter Hawtin Posted November 2, 2008 Author Share Posted November 2, 2008 I think we are all too prepared to pay the price of poorly designed products in this industry, first it was poor engines, then poor ARTF kits now cheap and nasty electronics sold at very high prices. I agree a full range check would have shown the problem, but the 30 ft range check was fine and I have never had this bad interference even with a really bad ESC, and all but two of my models are electric (out of 12).This was not just bad it was like hitting a brick wall, one second all was fine, then wam, nothing but jitters. I am not even sure my usual "full" range check would of picked up the problem.Peter Quote Link to comment Share on other sites More sharing options...
Myron Beaumont Posted November 3, 2008 Share Posted November 3, 2008 Sorry to hear of your loss' Talking of cheap Chinese engines -I have a 15 diesel I bought about 15 years ago that came with a life time guarantee on spares .It was £15 ish -plain bearing etc etc & is still one of my favourites ! Anyway I have ( another ) problem with lekky stuff & am reverting to ic .My new lipo rx battery has given up the ghost already &/or its voltage regulator .I was intending to use this type of power supply for all my models -NOT anymore ! Your experience has put the lid on it .Out come the nicads again .I have learnt as much as I want to from experiences like yours & so many others on the steep learning curve ( & expensive) I think thats enough moaning for a monday morning .Hang on --Why don't you get a pin anymore with your poppy ? Health & safety I suppose again! Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted November 3, 2008 Share Posted November 3, 2008 Myron said "My new lipo rx battery has given up the ghost already &/or its voltage regulator .I was intending to use this type of power supply for all my models -NOT anymore ! Your experience has put the lid on it" Myron. Your new Lithium battery gave up the ghost because because of operator error. Leaving it connected to the regulator after you had finished flying caused it to drain slowly to the point where it was discharged below a safe level. Quote Link to comment Share on other sites More sharing options...
Peter Hawtin Posted November 3, 2008 Author Share Posted November 3, 2008 I dont think that there is anything wrong with LiPo technology, it is the way we use it. I agree with Timbo, if you leave the reg connected to the battery then it has a very slow but sure drain. This will completly drain the LiPo below its minimum voltage and ruin it. ESC's do exaclty the same, I had a Jeti ESC that has an RX switch attached. For one reason or another I left the flight pack in the model over night and the following morning the 3S flight pack registered 0.7v! I tried everything to get this to take a charge including using a simple trickle charger at 50ma, but it had gone. If you are using a reg, always have it the far side of the switch. Peter Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted November 3, 2008 Share Posted November 3, 2008 Better still, do as I do, and UNPLUG THE BATTERY COMPLETELY - STRAIGHT AFTER LANDING. Quote Link to comment Share on other sites More sharing options...
Peter Hawtin Posted November 3, 2008 Author Share Posted November 3, 2008 How else you going to charge it (them in my case), in the airframe Quote Link to comment Share on other sites More sharing options...
Myron Beaumont Posted November 3, 2008 Share Posted November 3, 2008 Thanks for comments & advice .It seems you learn by mistakes OR not knowing .Having read all "destructions" again -There is no mention of disconnecting your regulator from the battery anywhere -Oh well ! For me I thought I could leave it in its place in the A/C as long as you disconnect the source of power (ie via a switch) to the Rx .Logic or not ?Timbo ---Why dont you (with your accumulated invaluable knowledge of all things electric )make up a list/article of all "do's & dont's" for the benefit of ignorami such as myself ? Having thought about it you are already doing all you can BUT a resume (no french accent) would be great ! A permanent reference sheet -whatever ? -Just like your invaluable lipo voltage/ state of charge sheet ? I'm still prepared to go a little bit electric & its not as if I dont understand Ohm's law or anything (I did mend TVs & audio equipment) a few years back -(dont mention surface- mounted components -my demise along with other repair men) What a monday morning but nice to read of other modellers being grumpy on most threads .Off to hospital now again-Wish me luck y'all Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted November 3, 2008 Share Posted November 3, 2008 Good luck with the hospital thing Myron Quote Link to comment Share on other sites More sharing options...
Tom Foreman Posted November 3, 2008 Share Posted November 3, 2008 Hey Peter I hope your joking about charging your LiPos in the airframe, if anything goes wrong then its BBQ time for the plane! Quote Link to comment Share on other sites More sharing options...
Tom Foreman Posted November 3, 2008 Share Posted November 3, 2008 Myron, there are some do's and don'ts from FMA enjoy. Quote Link to comment Share on other sites More sharing options...
Peter Hawtin Posted November 3, 2008 Author Share Posted November 3, 2008 Of course not doesnt everyone charge their LiPo's in their Airframe? Mine are charged on the dinning table in the lounge where I can see and keep an eye on the charging rate. I also estimate how long I feel they will take to charge and use a small kitchen timer to remind me to check they are done. I also use a temp monitor on the charger to kill the charge if it goes over a pre-set limit. Wife hates all the mess, but at least I know if there is a problem. Peter Quote Link to comment Share on other sites More sharing options...
Tom Foreman Posted November 3, 2008 Share Posted November 3, 2008 Cool, my charger makes very loud beeps at 90% and full charge. The missus hates it but at least I don't forget to unplug it once its charged Quote Link to comment Share on other sites More sharing options...
Peter Hawtin Posted November 3, 2008 Author Share Posted November 3, 2008 SAme with mine, drives my wife crazy. Peter Quote Link to comment Share on other sites More sharing options...
Bruce Richards Posted November 3, 2008 Share Posted November 3, 2008 I charge all my Rx Lipos in the model never had a problem and do not expect to either. Not my power packs though.I'm a mad optimist. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted November 3, 2008 Share Posted November 3, 2008 Peter Hawtin wrote (see)Of course not doesnt everyone charge their LiPo's in their Airframe? Mine are charged on the dinning table in the lounge where I can see and keep an eye on the charging rate. I also estimate how long I feel they will take to charge and use a small kitchen timer to remind me to check they are done. I also use a temp monitor on the charger to kill the charge if it goes over a pre-set limit. Wife hates all the mess, but at least I know if there is a problem. PeterYou estimate how long they will take to charge - Why? Any proper dedicated Lipo charger will use the correct constant current / constant voltage method to correctly charge and determine the terminal voltage and stop the charging process. If the packs are accessible to be able to insert the temp probe, then why not just remove them any way and charge outside the model - this is the safest method, as it also allows you to see if any cell is starting to puff. Quote Link to comment Share on other sites More sharing options...
Myron Beaumont Posted November 3, 2008 Share Posted November 3, 2008 Timbo What you're saying is be carefull isn't it? I reckon you're the only flier in whales who knows exactly what & what not to do -HENCE all the explanations you give out day after day .to stop us all (ME) making one mistake after another on our hyperbolical learning curve ! ie From the unknown to a disaster in a short time period Quote Link to comment Share on other sites More sharing options...
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