Problems with TP2409-12T
02-25-2009, 04:46 PM
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Problems with TP2409-12T
Hi all.
I'm having a weird problem with a Tower Pro 2409-12 that I recently installed in a little Cessna foamie.
The motor is rated at 200w by the manufacturer. Max efficient current is 23 amps, and max load is 25 amps. Suggested props are 7x6, 8x4, 8x5 APC.
Now, when I hook it up to a 25A ESC and 25C 2200 3s lipo, and measure with a watt meter (Wattsup), I get insane readings.
8x6 APC gives me 41 amps, and around 450 watts (turning the motor into a very effective electric heater. Don't worry - I only ran it at WOT for a split second to get a reading).
8x4.7 APC gives me 32 amps and around 350 watts. Clearly WAAAAAY too high.
8x3.8 APC gives me 28 amps and around 300 watts. Do-able, but with reduced component life (this was the biggest surprise - surely it should run fine on this prop?!!)
7x6 APC puts me right back at 31 amps.
A bit of research on the net shows lots of people raving about this motor, running 8x6 props with no apparent ill effects. But that's not what the numbers are telling me.
Anyone have any experience with this motor? Could it somehow be the ESC's fault? Or do I just have a dud?
I'm having a weird problem with a Tower Pro 2409-12 that I recently installed in a little Cessna foamie.
The motor is rated at 200w by the manufacturer. Max efficient current is 23 amps, and max load is 25 amps. Suggested props are 7x6, 8x4, 8x5 APC.
Now, when I hook it up to a 25A ESC and 25C 2200 3s lipo, and measure with a watt meter (Wattsup), I get insane readings.
8x6 APC gives me 41 amps, and around 450 watts (turning the motor into a very effective electric heater. Don't worry - I only ran it at WOT for a split second to get a reading).
8x4.7 APC gives me 32 amps and around 350 watts. Clearly WAAAAAY too high.
8x3.8 APC gives me 28 amps and around 300 watts. Do-able, but with reduced component life (this was the biggest surprise - surely it should run fine on this prop?!!)
7x6 APC puts me right back at 31 amps.
A bit of research on the net shows lots of people raving about this motor, running 8x6 props with no apparent ill effects. But that's not what the numbers are telling me.
Anyone have any experience with this motor? Could it somehow be the ESC's fault? Or do I just have a dud?
02-25-2009, 07:24 PM
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RE: Problems with TP2409-12T
I think you must have a faultily (is that a word?) wound motor - Peak Effic. suggests ~1700Kv and far lower amp draws than you are seeing. Whatever it is doing the specs do say 200W max... so you need to fit a small enough prop to get you there.
02-26-2009, 04:43 PM
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RE: Problems with TP2409-12T
Here's something quite interesting -
I discovered that the prop saver that I was using on the motor was a fraction of a mm off center. Which meant that every prop I was trying was slightly off center - just enough to cause a tiny vibration at full throttle, but not enough that you'd really notice.
When I fixed this, it dropped 2 - 3 amps off the power reading on every prop at WOT!
Amazing that such a tiny thing can make such a huge difference to power consumption.
I discovered that the prop saver that I was using on the motor was a fraction of a mm off center. Which meant that every prop I was trying was slightly off center - just enough to cause a tiny vibration at full throttle, but not enough that you'd really notice.
When I fixed this, it dropped 2 - 3 amps off the power reading on every prop at WOT!
Amazing that such a tiny thing can make such a huge difference to power consumption.
