Mike Downs Posted June 23, 2010 Share Posted June 23, 2010 I have converted my twin star to bhbrushless as follows 2X brushless Turnigy motors 2X22 A ESC's 8x6 APC props Everything worked a dream until suddenly when launching one motor suddenly made a growling noise and stopped....resulting in a bent model. The motors turn over smoothly ( for brushless) when turned by hand. I have put it all back together and tried it again .It goes OK four out of five goes.,where the same thing happens. Any ideas Quote Link to comment Share on other sites More sharing options...
Gaz Elliott Posted June 23, 2010 Share Posted June 23, 2010 I am not an electric guru but have you run it through a watt meter? I know the standard prop is not that big so it may be pulling too much for the esc - motor. No doubt tim will put you right direction....,,, Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 23, 2010 Share Posted June 23, 2010 If you havent done as Gaz suggests, then thats the first thing to check, then I may suspect a loose connection /break in the windings of one motor - if one of the three windings goes open circuit the motor will behave as you describe. Other possibilities include a duff ESC, FOD in the motor can, and so on. Quote Link to comment Share on other sites More sharing options...
Klippy Posted June 23, 2010 Share Posted June 23, 2010 FOD? in the Glossary please Quote Link to comment Share on other sites More sharing options...
Lazygit Posted June 23, 2010 Share Posted June 23, 2010 Foreign Object Damage (or similar). Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 23, 2010 Share Posted June 23, 2010 ...I always thought it was Foreign Object Debris - but close enough Edited By Tim Mackey - Administrator on 23/06/2010 09:28:44 Quote Link to comment Share on other sites More sharing options...
Mike Downs Posted June 23, 2010 Author Share Posted June 23, 2010 I haven't metered them individually at this stage as I would have to de-solder the power leadsb but I have checked the set up together,with results as below; Three runs of approx 40 secs AMPS WATTS 23.0 230 22.7 234 22.7 230 Needless to say the motor stall thing didn't happen on the treee runs The motors are 2x2830-1050 Turnigy The ESC'c are 2xpp-descau-22Amp Props APC Another thing ...How to check the individual windings? Cheers Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 23, 2010 Share Posted June 23, 2010 You are running the ESC slightly over their rating - and I have no experience ( or even heard of ) those brand ESC You could do a simple check of the winding using a multimeter on resistance range, probing across each of the "3 pairs" of wires IYSWIM. The small resistance reading should be pretty near identical for each reading.If that doesnt make sense, let me know and I will be more specific. Quote Link to comment Share on other sites More sharing options...
Allan Bowker Posted June 23, 2010 Share Posted June 23, 2010 Has the ESC timing been checked? I had a problem similar in the past and it was down to a combination of ESC timing setting and poor connection on one of the bullet connectors to the motor. Both worth checking. Quote Link to comment Share on other sites More sharing options...
Mike Downs Posted June 23, 2010 Author Share Posted June 23, 2010 Sorry guys..... But what is IYSWIM ? and ESC timing? What would be a good timing and how is it done? Thanks Mike Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 23, 2010 Share Posted June 23, 2010 If You See What I Mean.ESC Timing - your ESC manual should have details of how to set this correctly for the motor type...most outrunners prefer "hard" timing. Quote Link to comment Share on other sites More sharing options...
Brian Hammond Posted June 23, 2010 Share Posted June 23, 2010 are you using 35mhz or 2.4ghz,lot,s of strange things happen with the former! Quote Link to comment Share on other sites More sharing options...
Mike Downs Posted June 23, 2010 Author Share Posted June 23, 2010 I am using 35 MHz........I am working on the timing thing as Alan proposed...As it is a twin motor setup I am not sure if when setting the timing via the transmitter it will work this way....The ESC's are from 4-Max. and I am waiting for a response from their Guru! This electrcity stuff is very mind bending! What I want is to plug it into the power pack and then go..Cheers Quote Link to comment Share on other sites More sharing options...
Allan Bowker Posted June 23, 2010 Share Posted June 23, 2010 Programming from the transmitter is fine, just programme each ESC one at a time. Do not try to do both at the same time. Quote Link to comment Share on other sites More sharing options...
Andy Gates Posted June 23, 2010 Share Posted June 23, 2010 The other thing which does happen with twin escs is that if you have not isolated one of the BEC's then they can interfere with each other. Easiest way is to remove the red wire connection from one of the ESC plugs and tape it back so it is not used. If you do not like tape then heatshrink will do the same thing. If you have used 22amp ESC's and the combination is only using 23amps then you are not overloading the ESC's. Good luck.Edited By Andy Gates on 23/06/2010 18:02:30 Quote Link to comment Share on other sites More sharing options...
Erfolg Posted June 23, 2010 Share Posted June 23, 2010 My intial concern would be the current draw relative to ESC rating. In my opinion a one-to one rating of motor and ESC is very bad news. Even worse news is the amps drawn being the same as the ESC. But I do not think this would cause a growl. My next concern would be timing, again I do not think this would cause a growl. So I do not know, other thanconcern regarding the marginal set up. Quote Link to comment Share on other sites More sharing options...
Andy Gates Posted June 23, 2010 Share Posted June 23, 2010 Not that it would cause a motor to growl, but what power pack are you using for this setup? Quote Link to comment Share on other sites More sharing options...
Gaz Elliott Posted June 23, 2010 Share Posted June 23, 2010 The props...are they really required that size? I think the standard ones are 6x5 ish . although not sure if this would increase or reduce the amp . I have a dragon thing which i am repairing. One of the motors fails to start on increase of throttle but will turn with a flick. That is probably the esc but just not got round to installing a new pair. Quote Link to comment Share on other sites More sharing options...
Mike Downs Posted June 23, 2010 Author Share Posted June 23, 2010 Yhanks for that lot ........One further question Alan.....how do I isolate one ESC to do the programming? I have them wired with the power red cut on one of them. Regarding Erfolg's post... As far as the draw is concerned , the total is 23 Amps total, so each one should be taking 12.something, Regarding the growl ....this is accompanied by vibration just before stalling(.It doesn't jam stop) Re the power pack.....its a Flight tech 3800 11.1 V. Quote Link to comment Share on other sites More sharing options...
Allan Bowker Posted June 23, 2010 Share Posted June 23, 2010 You will need to plug 1 ESC into your receiver, programme that one on its own and then unplug it and swap it over with the other ESC and do that one. Is the 'growl' more like a 'cogging' sound? Quote Link to comment Share on other sites More sharing options...
Mike Downs Posted June 23, 2010 Author Share Posted June 23, 2010 Yes! Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted June 23, 2010 Share Posted June 23, 2010 It does sound to me like changing a timing setting could help. They do need to be set the same. I have had this failing to start once or twice, it wa's like the ESC can't detect the position or rotation of the motor or something. In the extreme Mike, you may end up unsoldering it all and swapping the two ESC's. See if the fault stays with one ESC or one motor. Just as a test, try them with no props on. If that always works it may indicate props that are too big. Quote Link to comment Share on other sites More sharing options...
John Privett Posted June 23, 2010 Share Posted June 23, 2010 Just a random thought - feel free to shoot it down in flames! Could running two ESCs off a common battery cause a problem? Some sort of interaction between the two ESCs? I've never tried a twin-electric motor setup, but it seems those I hear of have a battery for each ESC and motor. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 23, 2010 Share Posted June 23, 2010 Posted by Mike Downs on 23/06/2010 21:33:30:Yhanks for that lot ........One further question Alan.....how do I isolate one ESC to do the programming? I have them wired with the power red cut on one of them. Regarding Erfolg's post... As far as the draw is concerned , the total is 23 Amps total, so each one should be taking 12.something, Regarding the growl ....this is accompanied by vibration just before stalling(.It doesn't jam stop) Re the power pack.....its a Flight tech 3800 11.1 V. Ah, so the current figures you mentionedearlier are combined - in which case youre not exceeding the ESC capability . It sounds more and more like an ESC timing issue. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted June 23, 2010 Share Posted June 23, 2010 Posted by John Privett on 23/06/2010 23:05:52:Just a random thought - feel free to shoot it down in flames! Could running two ESCs off a common battery cause a problem? Some sort of interaction between the two ESCs? I've never tried a twin-electric motor setup, but it seems those I hear of have a battery for each ESC and motor. Unlikely, in fact I prefer and recommend people to use one battery rather than two. Quote Link to comment Share on other sites More sharing options...
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