I have a typical stunt ship electric system. If I set the timer for a short flight say one minute and keep programing for more rpm every flight, what will eventually happen? Will something over heat or will the rpm get to a point where it stops increasing despite the increased setting? What would fry first battery, motor, esc?

Thanks,
MM

If you hit a point where the motor hits its Kv limit for a given prop it won't go any faster. At that point you need to back off rpm ~20% - 25% to be able to have enough juice to fly the full 5min pattern. You can get a rough starting point by taking the motor Kv rating times the battery pack rated voltage (not peak off the charger) times ~90%. That will give you close to the max rpm setting, adjust from there.

Best,   DennisT

If you sized each component correctly, nothing will burn up.  You will hit max throttle or max power, max RPM, the motor and ESC will get warm to hot and the battery may also get warm.  Stop guessing - go shopping.  Amazon has a wide selection of servo testers, wattmeters and infrared thermometers for sale.  Then you know the exact numbers your power system is dealing with.

That said, a nose-over and stalled motor shaft on take-off is different.  Without prop strike protection or overcurrent shutdown the current flow skyrockets and things get warm fast until the magic smoke leaks out of the weakest component.

And how do you know that will happen Circuit Flyer??  ;-]

Quote from: Randy Meathrell on June 16, 2026, 01:10:57 PMAnd how do you know that will happen Circuit Flyer??  ;-]

I had that happen with a Brand new BA ESC and Motor. It fried the motor. I saw a puff of smoke.
Called Innov8ate and was told prop strike protection was not part of BA product line like Cobra. I switched to Cobra 🐍.

950 kv X 14.8 90% = 12,654 rpm if the prop's not too much load. Need more kv?

Quote from: CircuitFlyer on June 16, 2026, 11:52:48 AMIf you sized each component correctly, nothing will burn up.  You will hit max throttle or max power, max RPM, the motor and ESC will get warm to hot and the battery may also get warm.  Stop guessing - go shopping.  Amazon has a wide selection of servo testers, wattmeters and infrared thermometers for sale.  Then you know the exact numbers your power system is dealing with.

That said, a nose-over and stalled motor shaft on take-off is different.  Without prop strike protection or overcurrent shutdown the current flow skyrockets and things get warm fast until the magic smoke leaks out of the weakest component.

Optical tachometer as well. Have to know what full throttle static RPM is in order to stay below that for governed RPM. Need headroom for C&D accelerometer boost and enough to hear the run-up signifying end of flight.

Cheers,

Steve Manganelli

Quote from: CircuitFlyer on June 16, 2026, 11:52:48 AMIf you sized each component correctly, nothing will burn up...

I disagree.  If you size each component correctly for operating in a typical electric stunt run, with plenty of overhead so that you don't run out of poop in the vertical 8, there's no reason you couldn't end up designing your system so that a full-throttle run would overheat the motor or ESC.

If you're conservative then they may get uncomfortably warm but not burn up -- but then you added more weight than you needed to.

Quote from: Motorman on June 16, 2026, 06:11:18 AMI have a typical stunt ship electric system. If I set the timer for a short flight say one minute and keep programing for more rpm every flight, what will eventually happen? Will something over heat or will the rpm get to a point where it stops increasing despite the increased setting? What would fry first battery, motor, esc?

Thanks,
MM

Since the typical stunt ship electric system can and does vary quite a bit, and since you should design in some speed overhead so that you make it through the overhead eights, almost any of the above.  I don't think you'd fry your battery on a 1-minute flight.  Probably what would happen would be that the thing would end up running flat out with something like 4-second laps and (assuming your arm didn't get pulled off) the motor and/or ESC would get hotter than they should but not overheat.

If you did all that but didn't limit the flight time, you'd be a lot more likely to overheat something.

So don't do that.

I was going to take my stunt ship system and put it on a small plane and see how fast I could make it go. Smaller prop 7x8, one minute run time, Clown size plane. Eflite 15, 4s 2800, edge lite 50 and hubin fm9.

MM,
What motor size and Kv are you using?

Best,   DennisT

 Eflite Power 15 KV 950

That motor on 4S and 7x8 should run 17-18A at ~13500 RPM. Kv is low for prop size and battery.

Quote from: Motorman on June 18, 2026, 04:31:12 PMEflite Power 15 KV 950

I fly this motor a lot, in rc and c/l as stated above if matched correctly there shouldn't be any problems, a 11/5.5 prop 50 amp esc  with a 4 s 25c battery is well within it's rating, my rc setup is a 11-7, 50 amp esc 4500 4s, on a fun fly plane, I run it full throttle all the time, it comes down barely warm, they are great motors. 👍

Quote from: spare_parts on June 19, 2026, 06:06:47 AMThat motor on 4S and 7x8 should run 17-18A at ~13500 RPM. Kv is low for prop size and battery.

Ok, I found the Cobra C2826/6 about the same size with 1470KV They say it'll turn a 7x6 at 18,260. Not sure that would get me into 100mph territory (about 93mph?) but I think I would need a 75 amp ESC.

MM