P-Limited Motors - Im going to jump on the hot seat.

[ray schrauwen]

Funny thing.. I have had a couple of these motors constantly above 160.. They still run fine.. At nats in colorado in p limited offshore i ran all 4 heats with same motor.. Temps were right at 170 after 4 minutes.. That motor is still in my mono running strong.. Im a believer

I've gotten close to that temp with my AQ 1800. I push a df 33 around in p-spec sprint and I have propped down for offshore to make it last 4 minutes.

[Darin Jordan]

I have completed the first set of 60-second @ ~100A load test runs.

The following data represents the 4 of the most popular, currently allowed P-LTD Motors:

AQ1800
AQ2030
DYNM1500
DYNM1800

I will expect to compare all the other motors to these.

For these tests, I did the following:

1. BATTERY: 4S2P ThunderPower 70C 5000mAh packs (Total 10,000mAh), fully charged prior to each test run, and allowed to return to "normalized" temperature before each test.
2. Battery's were paralleled in order to attempt to maintain 15.0V +/-0.2V for the entire 60-second pull.
3. ESC: Castle Hydra EDGE 100 with water cooling on to maintain a consistent ESC temperature.
4. LOAD: Loads were applied using various arrangements of airplane propellers to achieve a ~100A, hopefully within +/- 5.0A, load.
5. TEMP: Temperature was monitored using a Spektrum DX-9 with AR400 RX and TM1000 Telemetry module, using a band style temp probe (normally used for wrapping around a cylinder head or exhaust tuned pipe).
6. Temperature was recorded within 1/4" of the forward endbell by taping the probe to each motor in exactly the same manner.
7. Temperature was recorded prior to each run, and again after each run, once it had climbed to it's maximum, determined by the point where it no longer increased (Absolute maximum recorded).
8. Temperature on the Castle Graphs are of the internal ESC Temperature.
9. LOADED VOLTAGE, MAX RPM, WATTS, and AMPS, were taken as an average over the course of a minimum of 40-seconds, starting approximately 10-seconds after the start of each run. Starting point is determined based on the point on the graph where the values are stabilized. You can see on the graphs below where the motors initially loads up and then tapers down to a steady state, generally after about 5-10 seconds at full throttle.
10. I am including the actual data graphs to be transparent and allow you to see what the nature of the test is. Enjoy. :)
11. I will consider this data to the be baseline by which EVERY other motor will be compared. Once a complete data set is available, a more direct comparison of these motors should be possible.

Here is the baseline data:

60sec_BASELINE_CHART.JPG


Here are the Castle Graphs for each motor in the Baseline test:

AQ1800:
60sec_AQ1800.JPG

AQ2030:
60sec_AQ2030.JPG

DYNM1500:
60sec_DYNM1500.JPG

DYNM1800:
60sec_DYNM1800.JPG

[JimClark]

That is quite a KV drop for those four motors

[Darin Jordan]

That is quite a KV drop for those four motors

It's quite a massive load, Jim.

Also, that's REAL KV minus the resulting calculated KV. Pretty typical.

The more efficient/powerful the motor, the less KV Drop you'll see.

[JimClark]

Thanks for splaining it better. That Dynamite 1500 looks very good then compared to the others. More efficient for sure.

[Darin Jordan]

Thanks for splaining it better. That Dynamite 1500 looks very good then compared to the others. More efficient for sure.

I agree... but what do I know.

Some indicators to look at are going to be KV Drop, Temperature Delta, and resulting MAX RPM.

A more efficient, more powerful motor, should provide more KV and should probably have less temperature gain over the test time.

However, that could be skewed by the motor construction. It's possible for a motor to be POWERFUL, but heat up do to the materials/mass of the motor.

Guess we'll figure more out about that as we get through these tests.

[Brushless55]

I agree... but what do I know.

Some indicators to look at are going to be KV Drop, Temperature Delta, and resulting MAX RPM.

A more efficient, more powerful motor, should provide more KV and should probably have less temperature gain over the test time.

However, that could be skewed by the motor construction. It's possible for a motor to be POWERFUL, but heat up do to the materials/mass of the motor.

Guess we'll figure more out about that as we get through these tests.

that is what I am paying attention to

[Darin Jordan]

Concluded testing with the 3650-sized motors last night, with predictable results.

Same test parameters as described above.

Physically, these motors are representative of the actual rotor/stator size to our present P-LTD motors. However, being 4-Pole vs. 6-Pole, they have less torque, and therefore don't appear to handle the 90-100A currents well.

One motor finally bit the dust as well. The SSS3650-1500 motor, when loading it enough to push it into the test range (90-100A), started smoking at the 25-second mark. Data shows it was only pushing 74.0A and 1100W.

Event the Neu 1410-2Y didn't hold up well. To be fair, this isn't a "real" NEU 1410... It's one of their "cheap motor" line ($49.95) and not really a "Neu".

Anyhow, if the goal was to reign in the performance of the class (would have to limit setups to 75 or 80A max), the 3650-sized motors might be an option. In comparison to the present P-LTD motors, they aren't. I won't be testing this size any further.

Here is the Data as of now. I'll start testing the 3660-sized motors tonight.

DYNM2000:
Slide11_DYNM2000.JPG

TP3650-1970:
Slide12_TP3650_1970.JPG

LBP3650-1840:
Slide13_LBP3650_1840.JPG

NEU1410-2Y:
Slide14_NEU1410_2Y.JPG

SSS3650-1500:
Slide15_SSS3650_1500.JPG

[Darin Jordan]

Here is the updated Data Chart for the 60second LOAD Tests:

Slide16_CHART.JPG

[ray schrauwen]

Where did your test AQ2030 come from??? Steve, AQ, ???

[ray schrauwen]

Also, what is the part # for the DYNM1500 You are testing please?

[TRUCKPULL]

Hello Darin

In your test results, under Motor load you list;
G7 x 6
7 x5G + G5 x 5
8 x 6G cut
and again a 7 x5G + G5 x 5

What do these numbers mean?
I would suspect Dia. & pitch?
Is one prop 10% or 20% more load then the other??

Larry

[T.S.Davis]

Ray, pretty sure that's a DYNM3835.

I baked one just before the water got cold. My fault. I was screwing around with too much pitch. Finally pissed it off enough to kill it. They're solid motors but your boat needs to be setup for bigger props. My opinion at least. Your not going to run a 42x55 on it is what I'm saying. Sure runs nice in a 10th scale.

[ray schrauwen]

Ray, pretty sure that's a DYNM3835.

I baked one just before the water got cold. My fault. I was screwing around with too much pitch. Finally pissed it off enough to kill it. They're solid motors but your boat needs to be setup for bigger props. My opinion at least. Your not going to run a 42x55 on it is what I'm saying. Sure runs nice in a 10th scale.

I was curious a since I've seen some pretty inexpensive on line. If I can turn a m447 on a AQ 1800, I figured I could adjust easily with one of these for spare.

Back to the mad scientist Darin Jordan... Nice data so far!

[Darin Jordan]

Hello Darin

In your test results, under Motor load you list;
G7 x 6
7 x5G + G5 x 5
8 x 6G cut
and again a 7 x5G + G5 x 5

What do these numbers mean?
I would suspect Dia. & pitch?
Is one prop 10% or 20% more load then the other??

Larry

Larry, I'm not sure how to answer your question to your satisfaction, but my version of "load" is however much it takes to push the motor into the 90-100A range. These designations mean things like "Graupner 7" x 6" Prop", or "7x5 Gray Prop plus Graupner 5x5", etc...

The point is to push each motor to a similar POWER output (WATTS) and see how they stand up. That lets you compare a 1500KV motor to a 2000KV motor, because POWER is what matters, ultimately.