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

[Darin Jordan]

I was talking with someone up in the NW several weeks back, and he said any 36mm can works in P Limited up there, and thought dang !
that would be an unfair advantage running the 3674 motors

I don't know who you are talking too, but that's not true.

PSFEMBC has opened up the classes to some options, but they are examples like the TP3660-1950, or the Turnigy 3659-1900KV.

There may be guys trying other things, but if they do, they are generally running for no-points.

[Darin Jordan]

NEU makes a 36mm motor also.

Larry

I'm testing the Neu 1410-2Y. Seems about in line with other motors of it's general size.

Testing continues.

Thus far, I've run the 16 sample motors I have through the following:

NO LOAD
5.5x5.5 Prop Load (~45-50A load on AQ1800)
6.0x6.0 Prop Load (~60-65A load on AQ1800)

Next up is a 7.0x6.0 Load, which on an initial test run, pushes the AQ1800 motor into the 85-Amp load range.

We'll see how everything looks after that set of tests as to whether I push these even further. Not really interested in blowing anything up on the bench, and turning a prop like this at 20,000+ RPM is a little nerve wracking.

[rayzerdesigns]

Sweet

[T.S.Davis]

We'll have data overload.

"Yes yes Basil, but what does it all mean?"

Kinda looking forward to having some data instead of speculation.

[Darin Jordan]

OK, guys... here are the results of my initial motor tests. I haven't drawn any conclusions from these yet, through a picture is forming.

First a quick note on the test setup parameters:

1) Two 4S packs were used, both ThunderPower 70C 5000mAh 4S cells
2) Batteries were charged before testing EACH motor, with voltage verified and recorded for each pack, and each cell in the pack, using a HYPERION Battery checker.
3) ESC used was a Castle EDGE 100, with 5-degrees of timing, and water cooling installed.
4) MOTOR, ESC, and BATTERY temps were recorded before each test run and tests were run using CONSISTENT temps. +/- 2-degrees in most cases.
5) TEMPS were taken on the motor endbells, ESC power board, and Battery end near the wires. In other words, the same locations for each test.
6) EACH engine pull was 6-7 seconds.
7) DATA (AMPS, VOLTAGE, RPMS, ETC), were recorded based on a 5-second sample of data, taking the average across that time span.
8) PRESENT P-LTD Approved motors are listed in WHITE cells with RED text.
9) Motors tested were as follows:

AQ1800 - AQUACRAFT
AQ2030 - AQUACRAFT
DYNM1500 - DYNAMITE/ProBoat
DYNM1800 - DYNAMITE/ProBoat
DYNM2000 - DYNAMITE/ProBoat
LBP3650-1840 - LEOPARD
LBP3660-1900 - LEOPARD
NEU1410-2Y - NEU Motors
SSS3650-1500 - TFL
SSS3650-1968 - TFL
SSS3660-1500 - TFL
SSS3660-1800 - TFL
SSS3660-1968 - TFL
TP3650-1950 - TP Power
TP3660-1950 - TP Power
TURNIGY SK3 3659-1900 - TURNIGY

TEST #1: NO LOAD
PURPOSE: To determine the REAL KV for each motor.
NOTE: The Idle Current from this test could provide insight as to motor efficiency, but in many cases was too low to be recorded, so I'm ignoring it for now.
NOLOAD.JPG


TEST #2: 5.5x5.5 Prop Load
PURPOSE: To determine motor power under a mild loading, near the motors "factory rating" for loaded amps.
5x5_LOAD.JPG


TEST #3: 6.0x6.0 Prop Load
PURPOSED: To determine motor power under a loading near a "normal use" loaded amps.
6x6_LOAD.JPG


TEST #4: 7.0x6.0 Prop Load
PURPOSE: To determine the motor power under a heavy, near 100-AMP load.
NOTE: Do to the wide range of KVs and motor sizes, ONE load isn't going to equally load EACH motor to the same AMPs. This test will simply show how each motor responds to a SPECIFIC load. Later testing will attempt to load EACH motor to the SAME AMP load, which should provide a more direct comparison of power output.
7x6_LOAD.JPG


COMING UP: The next set of tests will take a bit longer to run each. Based on the data gathered so far, I'm going to vary the loads on each motor in order to test EACH at an AMP load at or very near 100A. I'm going to run these for a much longer period of time, measuring the temperature before and after the run. I will be paralleling the batteries in order to provide a more stable voltage supply (Sorry, I wish I had a high-amp variable power supply, but those are REALLY expensive, so batteries will have to suffice).

The goal will be so try to record 60-seconds of data for EACH motor, with starting/ending temps, etc. Ultimately, THIS will tell us which motors are equivalent and which are clearly outside of the present P-LTD performance range. Based on the data thus far, it's pretty clear which motors currently appear to exceed the present performance levels. More data will make clear exactly where each stands.

Sorry it's taken/taking so long, but there is a LOT involved in doing this right.

OH, and just so it's clear and I'm being transparent, here is an example of the full data taken, including starting battery/temp parameters. This was done for ALL test. Leaving this data out of most postings, simple because it's clutters the results.

7x6_LOAD_FULLDATA.JPG

[covedweller]

Quote from Red Dwarf "but what IS it?" Great work Darin, that had to take some time and effort, and for that, thank you! Entire books could be written on what I do not know about electronics, and loads there of, but you have posted information that will be helpful even to me. Now I can go on to guessing about props, hulls, weight, batteries, esc's, and wire size and connectors.

[properchopper]

In the last few years I've been living in (and watching grow) the "Ltd" class. Tried everything. Based lots of trial/effort/bucks on "seat of the pants" guesstimating. Now FINALLY some empirically backed up lab results.

Darin for President

[Darin Jordan]

Quote from Red Dwarf "but what IS it?" Great work Darin, that had to take some time and effort, and for that, thank you! Entire books could be written on what I do not know about electronics, and loads there of, but you have posted information that will be helpful even to me. Now I can go on to guessing about props, hulls, weight, batteries, esc's, and wire size and connectors.

Don't guess just yet... This preliminary testing is to try to determine what MIGHT be considered for an "approved motor list"... Nothing at all has been officially determined.

[T.S.Davis]

Fascinating.

I know you have a ton more work to do but something that caught my eye on the last 7.0x6.0 test. Same load for all the motors and the output varied as much as 870 watts or 1.16 hp.

I can't draw any conclusions yet either. Great stuff though so far.

[RandyatBBY]

Thanks Darin, so much data my head hurts after looking at it for 10 minutes. You have a good anilical skills.

[T.S.Davis]

bahaha I'm positive Randy means analytical. Nearly peed myself.

[Darin Jordan]

Fascinating.

I know you have a ton more work to do but something that caught my eye on the last 7.0x6.0 test. Same load for all the motors and the output varied as much as 870 watts or 1.16 hp.

I can't draw any conclusions yet either. Great stuff though so far.

Exactly. That's why Tyler suggested that I try to vary the load to get EACH motor pushing around 100-Amps, and stretch the time out to 60-seconds to get a good read on the heat build-up, etc.

The motors that survive that test will likely narrow the list down a lot.

It would appear, however, that the 3650-sized motors are more representative of the P-LTD power levels than the 3660-sized. We'll see more clearly if that's the case after the next tests.

[rayzerdesigns]

awesome work darin, im liking my dynamite 1500s even more now..lol..that last load test is crazy, some motors well over 100 amps

[T.S.Davis]

The Turnigy and TP 60 series motors put out a lot of power if they can take the heat.

[rayzerdesigns]

wish dynamite would bring back their 1800