Spartan, tear it down to build it up

[Brushless55]

I dought there is any assembly lube used on these shafts
but do use a high quality grease
all grease will discolor some

[GeoVW72]

well, chalk another one up
esc has started the "flutter" and the motor's lost it's poles

ambient 45*f

Run#1: 2x 2s
esc: 50* motor: 98*

Run# 2: 2x 3s
esc: 70* motor: 123*

Run# 3: 2x 3s
esc: 99* motor: 165*-188*
5 min into run 3, running straight and it just starts the flutter.
Bring it in and take the temps, 10 sec later the receiver starts the over temp blink and the motor temp rose to the second reading.
Waited 10 min for things to cool down then sent it back out to make sure it wasn't a fluke, it wasn't

Dissection:
Motor has no feel of the poles

A few black fiberglass strands were floating around the can, not 100% sure where they came from, seems around the rotor caps
bearings are ok, rear is smooth, front feels a little dirty, both were lubed with Boca grease
motor smells strongly of burnt electronics, no apparent damage to windings, maybe the epoxy cooked

Flex is fine, lubed liberally with Pro boat grease, sheen still on the interior and exterior of the liner. The stub shows some odd wear patterns though

esc shows no damage, not that much can be seen.
temped everything;
heat-sink: 99*
caps: 110*
motor wires: 101*
batt plugs: 122*

Conclusion:
Running around 7 minutes on the set up is the limit before the components are heat soaked, motor damage due to heat may have contributed to the event based on the fact that the arming tones were not as they previously had sounded.

Next step:
Test y-ing the line to reduce motor temp, explore consequential outlets and pick-ups......after things come back from traxxas

[GeoVW72]

Got a motor back from Traxxas, mostly in one peace.



other things of note



Stator wrap missing so bad that you can see the outside of the can.
and



Motor shaft also had set screw mount marks
Try, try again.
Have the Y-ed set-up ready to go



Results tomorrow

[GeoVW72]

looks good, so far
got the eagle tree installed

ambient: 32*f

Run #1:
2x 2s 5200 40C
Time: 12 min
Max speed: 25 mph
Max amp: 45
Esc: 54* Motor: 70*

Run#2:
2x 3s 4700 45C
Time: 6 min
Max speed: 45 mph
Max amp: 103
Esc: 70* Motor: 125*

Run#3:
2x 3s 8000 20C
Time 11 min
Max speed: 45 mph
Max amp: 115
Esc: 90* Motor: 125*

Eagle tree got me excited when I first downloaded the run, listed the max as 54 mph , but then went through the playback and towards the end the data went funky because of the water in the hull.
I really hoped that the 8000mah packs would get the mythical 20 min run time, but you're going to need twice that to even scratch it

To recap set-up; turn fins squared up with the hull, trim tabs level, strut level for this run, batteries mid-front CG around 25%.

[dag-nabit]

Just curious if you got a reading for average amps.

The max amps are well within the 300 amp burst rating of the stock ESC, but I'm wondering how close the average amps are to the 80 amp continuous rating for the stock ESC.

Kevin

[GeoVW72]

Just curious if you got a reading for average amps.

The max amps are well within the 300 amp burst rating of the stock ESC, but I'm wondering how close the average amps are to the 80 amp continuous rating for the stock ESC.

Kevin

I didn't download the data after every run, so it was one long stream, have to play with the software some and see what I can make it do.
Watching the play-back 60~80 was around the average which is where I think they came up with the rating.
300 is way out there, I think that's just what they could run until it blew.
ie. the way out hp # for 5 sec.

[Brushless55]

Just curious if you got a reading for average amps.

The max amps are well within the 300 amp burst rating of the stock ESC, but I'm wondering how close the average amps are to the 80 amp continuous rating for the stock ESC.

Kevin

Just to get an idea
on run #3 with 8000mah packs for 11min run down to 20% would come up at about 35amps cont.
run #1 would be about 21amps cont.
run #2 would be about 38amps cont.

[dag-nabit]

Just to get an idea
on run #3 with 8000mah packs for 11min run down to 20% would come up at about 35amps cont.
run #1 would be about 21amps cont.
run #2 would be about 38amps cont.

Thanks Brushless,

Well within the "rated" limits of the ESC, which serves to further confirm everyone's suspicions that the ESC problems are quality related, rather than it being undersized for 6S setup.

Kevin

[GeoVW72]

Brushless55:
I agree that the math is correct for the average amp consumption throughout the run, but is not the average amp load on the esc.
I will work on presenting the data in support.

dag-nabit:
All of traxxas's esc are suffering from the same quality issues. Based on the fact that they changed the esc from the prototype, I think it is speced well, but we all know the motor is not up to the task.
That is one of the major roots of the issues. The motor is under speced and inefficent so it generates heat that isn't carried away by the cooling system. That translates into a higher amp draw on the esc and a higher esc temp, that in the standard series loop transmits and compounds to the motor issue until the system melts down.
Around 7-10 min as far as I've found out

More data and better presentation tomorrow

[Brushless55]

Brushless55:
I agree that the math is correct for the average amp consumption throughout the run, but is not the average amp load on the esc.
I will work on presenting the data in support.

More data and better presentation tomorrow

average amp consumption is average amp load

[GeoVW72]

not perfect, but I have graphs

ambient: 38*f

Run# 1: 2x 2s shoved the packs all the way back
Esc: 54* Motor: 70*
Speed: 30 mph


Run# 2: 2x 3s started with the packs back, then moved them forward
Esc: 70* Motor: 100*
Speed: 44

YT Vid is after I moved the packs up

Run# 3: 2x 3s
Esc: 94* Motor: 127*
Speed: 45

YT Vid

I tried to create an amp spike by launching from a dead stop, but the esc seems to have a current limit or soft start
ESC temp is a little concerning, as the last one failed at 99*, but what concerns me more is the temp of the caps.

I've seen temps of 140-160*f on the caps of this esc and being that traxxas has potted and sealed them so they don't blow, I wounder what temp they will go thermo-nuclear at.
May have to add a cap board to help the fixing

Commence more tweaking

[Brushless55]

You have a peak of 122amps, that is not a soft setting, that sounds norm..

[JPriami]

Nice work Geo

[Brushless55]

Nice work Geo

I agree, and I think this is the first real readout on the stock motor..

[shctexas]

Ok, fresh stuff in boat 4082 1450kv seaking, 180 amp esc, in hull h20 pick-up and x645 prop. 43 mph before prop 49+ after prop....yikes! I can't imagine 58mph but I'm gonna try to get there. There's some pretty serious torque roll when you nail-it; not quite as dramatic when power is rolled on. All in all a success