AMP draw on Huff motor

[Rags901]

New to FE and may have smoked (literally &#128580 4 motors my first season. Had them all rebuilt by Huff and sent him a new Leopard for rewind. Came back marked 2660kv, as opposed to the 2060 through 2160 of the others, so was saving it for a special occasion. When the time came, put it in a new NexGen P-LTD Hydro and propped down for testing. In less than 2 minutes, 180 Hobbywing thermal shut down, 5000 Dynogy bulged and shrink wrap split. Went smaller still on prop and went like a bat out of hell, but ESC hot again and bulged another 5000 pack. Went to an OSE 4012 prop and smoked a 3300 pack in one minute 45 seconds.
Swapped out to a Huff SSS 2069kv, propped up and runs great!

How do you control that kind of AMP draw into useable power? Speak in simple terms, because that?s what I understand best!

[Bande1]

what does 2 minutes mean exactly? are you lapping at full throttle? Run time like that is more like 90 seconds. so yeah you will puff a battery trying to go 2 minutes.

my P limited hydro - 2000kv, 1716 prop, 7200mah - 6 laps at full throttle about 90 seconds runtime = 10-20% remaining
amp draw is around 165A continuous. that is the ragged edge of the system. the motor is on the verge of frying. maybe 53-55mph.

so a 2660kv even with a 4014 (I assume you mean 4014 and not 4012) is HOT. Thats about 65mph. On 4s thats about 3500w / 14v = 250A
You have max 30 seconds runtime. by that I mean 30 seconds of full throttle. I would consider that more like 10 seconds to be safe. That motor is for speed running or 2 lap time trial running. Nothing more.

so yeah your situation makes perfect sense. you are wildly underestimating the amp draw and undersizing batteries. or running way too long. with P limited 55mph is smoking fast. like melting stuff type fast. get an ESC with data logging or an Emeter2 system and you will find out real fast that your amp draw is wayyyy higher than you thought.

[Rags901]

Your response was exactly what I needed! When I got the boat from Mark Grim, he sent me his 1819 prop, which stays in the toolbox until I educate myself. I started with an H4416, then H4216 and then an H4016 when I smoked the 3300 on the last run with the rewound Leopard. With the SSS and an OSE H4216, the heat gun showed all components well within range and speed was very gratifying and within my piloting capabilities. By the way, I was setting up for NAMBA heat racing.

Thanks for the thoughtful and well written response.

[Bande1]

Your response was exactly what I needed! When I got the boat from Mark Grim, he sent me his 1819 prop, which stays in the toolbox until I educate myself. I started with an H4416, then H4216 and then an H4016 when I smoked the 3300 on the last run with the rewound Leopard. With the SSS and an OSE H4216, the heat gun showed all components well within range and speed was very gratifying and within my piloting capabilities. By the way, I was setting up for NAMBA heat racing.

Thanks for the thoughtful and well written response.

marks props are crazy. he was at my club for the time trials last week and the guys who contend with his times in nitro couldnt begin to keep up with his p-limited riggers pace. They tried a 1717 @ 1950kv TP 3630 in their very nice prototype rigger and promptly smoked it. Then a dynamite 3831 and smoked that at around 56-58mph. mark is runnung over 70mph so its not even in the same universe. I know him and his son run NEU motors, though.

[RaceMechaniX]

Rags,

The 1918 is way too stout for a 2660kv motor. The 1918 would be more appropriate for a 2000-2200kv motor like the original kv motors you had. Most of us run the same ~2700kv motor with a 1717 or smaller prop. You will need more than a 180A controller and definitely at minimum a 65C or better battery. Many are running a 5800-7700mAh capacity battery and the go to ESC is a Castle X8S Hydra.

Huffs rewinds are capable of almost double the amperage of the old AQ2030 motor and still 30% more than some of the stock Leopard and TP motors. 200A spikes and 170A continuous is fairly commonly for P-Ltd rigger.