cagey Posted July 2, 2012 Share Posted July 2, 2012 To be brief. I was enjoying a test flight after beefing up the U/C,on my FMS P 51d. DX7s and AR6200 on board. Gentle right bank at 70 % throttle, when the motor was heard to wind down and total loss of control followed by a soil hardnes test. Both the main and satellite r/x lights were on solid and all functions reacted perefectly after returning the mangled remains to the pits. Further tests gave me a 45 metre range test and no glitching evident,. In retrospect perhaps I shouldn't have flown as on opening the throttle to take off the motor seemed to stutter a bit before responding, did this at full throttle, then behaved as normal, so I foolishly went for a flight. Bad move ? What makes a motor react like this ? What can I do to test all is well ? Can I trust my set up again without returning it all to HH for the usual NFF ? Be obliged for any advice guys. Quote Link to comment Share on other sites More sharing options...
Garbo Posted July 2, 2012 Share Posted July 2, 2012 If one of the three motor wires comes away the motor stutters, perhaps you had a poor connection on one if the wires between the motor and esc. Quote Link to comment Share on other sites More sharing options...
Oldbaldfella Posted July 2, 2012 Share Posted July 2, 2012 Tip stall? Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted July 2, 2012 Share Posted July 2, 2012 bad luck cagey...a stuttering motor could mean the controller timing was wrong...worth checking it out.... ken anderson ne.1 ..... stuttering motor dept.... Quote Link to comment Share on other sites More sharing options...
cagey Posted July 2, 2012 Author Share Posted July 2, 2012 Thankyou for the replies peeps. Ken, regarding the possibility of an out of sync ESC, how do i do this ? If I.m right the FMS stock ESCs are non programmable, so there is no supplied beep code for them, or cards to do this with even if you had a code. So Hmmm? Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted July 2, 2012 Share Posted July 2, 2012 Cagey, I too would suspect the connections - ESC to motor. A good "bang" on impact may now be hiding a dodgy connections. I'd give all three wires a good waggle and a tug then test, then do it again! BEB PS If you were at 70% throttle - and in a "gentle turn" as I think you said - I can't see it being a tip stall. Edited By Biggles' Elder Brother - Moderator on 02/07/2012 23:32:34 Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted July 2, 2012 Share Posted July 2, 2012 But why would a loose motor conxn cause "total loss of control" ? Unless as someone suggested the loss of thrust resulted in a stall. Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted July 2, 2012 Share Posted July 2, 2012 The motor shutting down could have been the fail safe activating following an rx power supply problem or radio link problem . Double checking the lipo connector and soldered joints is advisable as a brief total power loss would produce the same result. Tom. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted July 3, 2012 Share Posted July 3, 2012 I dont think the throttle failsafe would activate on power supply problem Tom - only on signal loss? Of course, if the power was removed, the motor ( and everything else ) would stop - but not because of the failsafe IYSWIM Quote Link to comment Share on other sites More sharing options...
John Muir Posted July 3, 2012 Share Posted July 3, 2012 ESC overheat and shutdown? Duff connection or motor causes resistance increase (stuttering motor might be a clue) and ESC cuts out. Motor goes off and no control. Once back on (or in) the ground, ESC cools down and everything seems fine again. So definitely check connections and also motor. Unfortunately could also be a dodgy ESC. These FMS models do have the radio powered through a built in BEC in the ESC don't they? Quote Link to comment Share on other sites More sharing options...
Miroslav Posted July 3, 2012 Share Posted July 3, 2012 The OP's issue sounds like he definitely had an esc brown out which resulted in his plane having an unfortunate plane/ground interface. FMS models come with all the bells and whistles, e.g. flaps, retracts etc all pulling (via the rx) on the esc. Surely a separate bec is a good idea in case the esc goes into brown out mode (and thus cuts power to the rx) due to a sticking servo, retract etc or from flying wot for too long? In this instance, while you might lose the motor, you have a chance to land her by having the control surfaces still working as they are getting their power via the rx which in turn is being powered through the separate bec. An esc brown out is hard to find post crash as it would have cooled down and resumed normal function, albeit amongst a pile of foam that once looked like a plane. Quote Link to comment Share on other sites More sharing options...
cagey Posted July 3, 2012 Author Share Posted July 3, 2012 Many thanks for all the suggestions peeps. Seems as if I'm spoiled for choice as to what to look at first. I'm going to rebuild it I reckon, being as I'd really roughed it up with the oil pastilles to make it look well weathered the repairs won't look out of place. Ho hum. Till that's done I'll go through all the tugging wires etc and test runs with a watt meter but more than likely choose a more reliable ESC/motor combo, or at least a known make with a good reputation. Damned annoying to have this happen (again !) happened with my Squall and MX2, different set ups each time, without an obvious fault, though I guess I'm not the first and won't be the last. Quote Link to comment Share on other sites More sharing options...
Former Member Posted July 3, 2012 Share Posted July 3, 2012 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted July 4, 2012 Share Posted July 4, 2012 Posted by David M on 03/07/2012 17:33:37: The OP's issue sounds like he definitely had an esc brown out which resulted in his plane having an unfortunate plane/ground interface. FMS models come with all the bells and whistles, e.g. flaps, retracts etc all pulling (via the rx) on the esc. Surely a separate bec is a good idea in case the esc goes into brown out mode (and thus cuts power to the rx) due to a sticking servo, retract etc or from flying wot for too long? In this instance, while you might lose the motor, you have a chance to land her by having the control surfaces still working as they are getting their power via the rx which in turn is being powered through the separate bec. An esc brown out is hard to find post crash as it would have cooled down and resumed normal function, albeit amongst a pile of foam that once looked like a plane. I dont know of any ESCs that feature a brown out issue - its a receiver thing not an ESC. Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted July 4, 2012 Share Posted July 4, 2012 Posted by cagey on 03/07/2012 21:28:09: Damned annoying to have this happen (again !) happened with my Squall and MX2, different set ups each time, without an obvious fault, though I guess I'm not the first and won't be the last. Whoa! You mean this has happen before!? You didn't mention that earlier - I don't think so anyway! That puts a rather different complexion on matters. Did the previous incidents follow the same MO - ie stuttering motor then loss of control? BEB Quote Link to comment Share on other sites More sharing options...
Former Member Posted July 4, 2012 Share Posted July 4, 2012 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted July 4, 2012 Share Posted July 4, 2012 gagey--- you need to go back to basics with your set up for electric...... more so if this has happened in the past and you have lost other models.....me i would be thinking along the lines of not using most of the stuff again...... ken anderson ne..1... basics dept... Quote Link to comment Share on other sites More sharing options...
cagey Posted July 4, 2012 Author Share Posted July 4, 2012 Sure sounds as if I've opened a bag of worms for myself here. To enlarge on past events with the Squall and the MX2, both were flown using the stock set ups, different r/xs and lipos but both on a Spektrum DX6i. The FMS mustang, again, stock set up, different r/x and lipos with Spektrum DX7s. So no commonality there. All lipos were as recommended and in good charge state, and the usual full power ground checks carried out with complete confidence. The stuttering BTW was at the first throttle input, and even full stick gave no response, just a juddering. If a little encouragement were given with a cautious flick on the spinner, it would pick up and behave itself.from then on. Yep. was an idiot to fly wasn't I Grr ! So, back to basics, as Ken Anderson advises. Possibly a better charger and cell checker'd help to be sure of lipo condition and as already said a new motor ESC combo, if I could be sure what to use. And fresh bullet connectors throughout also. I believe the V2 of this a/c uses a different set up so maybe there's a clue, although I'd like to find out if the review model our Mr. David Ashby tested back in 2010 is still flying on it's original bits and undamaged ? I'm extremely grateful to all who've taken the time to help and promise will update in the future or. Cheers all. Ken Gerrard, aka cagey ..... peed off dept. Quote Link to comment Share on other sites More sharing options...
Depron Daz Posted October 25, 2013 Share Posted October 25, 2013 I bought the FMS P51 v6 last year, and it was in the air for 3 minutes before the ESC gave way causing a crash. Contacted CML who import/distribute them and they replaced the whole plane upon return of the electronics from the old one. They denied that the ESC's BEC was too small but having researched on RCG there are loads of people who suffered the same fate. Strangely enough the v7 now has a bigger BEC. However, since this crash, I now fit separate UBECs on all of my planes. Quote Link to comment Share on other sites More sharing options...
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