Problem with: LRP#80950 SXX TC Spec Shutting Motor Down

[lucas-b4-b44]

Products used together (all very very new) :

ESC: LRP#80950 SXX TC spec Brushless Speed-Control (Setting: 1.1.1.1 fan not installed)

Motor: LRP#50672 Vector X12 Brushless Modified - 6.5t (Timing: 00 factory default)

5300 Battery: LRP#79868 LiPo Competition Car Line Hardcase 5300 - 40C - 7.4V

4800 Battery: LRP#79866 LiPo Competition Car Line Saddle Hardcase 4800 - 40C - 7.4V

Buggy: Team Associated B4 Factory Team 2WD Buggy

My ESC shuts down motor after about 4:30 to 5:00 mins of use with a fully charged 5300 Battery, when full throttle for a couple of seconds both Mode lights flash alternately then stop and go to default solid red light on mode, the temps in celcius are: Motor=50, ESC = 55, Battery=23 so no problems with heat.

Waited 5 mins still wouldn't start up motor.

Tested voltage of battery on Hyperion EOS0720i Net3 Charger = 65% or 7.857v for pack or 3.928v per cell. So can't be low voltage cutoff?

Tried different 4800 Lipo pack, car started straight away, swapped back to first battery now runs again??? used initial 5300 battery another 7 mins and fine no problems.

But this occurred once more with 5300 Lipo pack after 4:30 mins again..... motor cuts off wont start. Put in an NiMH battery to test: motor runs again.

This has happened, twice in the 3 times I've used the setup, and I've only driven the car 3 times with this new 5300 lipo pack. It has not occured with my B44 which is using the exact same setup as above with 4800 Lipo, but with 5.5T x12 motor (obviously diff gearing etc...same ESC with fan installed)

Could this have occured due to over current protection??? and resets after a while, why would anything be giving too much current?

I'm loath to have to send my ESC & Battery back, hope there is an obvious reason I can remedy

Sent same letter to SMD, will post it here when it comes too.

Thanks for your time .

Regards Lucas

[Body Paint]

It sounds like the speedo is thermalling.

A. What gearing are you running? Over heating is most commonly caused by being overgeared.

B. You should try fitting a fan to the speedo, this will help if speedo is thermalling.

I have never seens a motor come off at just 50 degrees C after 4.5 minutes, are you sure you checked that correctly?

[Alex H]

A friend of mine has got the exact same problem. Same esc and motor.

[Marvin]

That was my first thought, no fan with a 6.5? Most ESC manufacturers seem to say that any wind lower than a 10.5 needs a fan. Also, even if the outside temperature of the SXX was 55, the internal temps would be far higher - so I think it's probably the thermal cut-out, hence why you cannot drive it for a while afterwards - it's waiting to cool down.

[lucas-b4-b44]

Hi, thanks for posts.....

However this ESC manual it states: "The fan can be mounted on top of the heatsink and should be used for tough applications in hot conditions such as TC Modified or 4WD OffRoad. As a guidelinewe recommend using the fan with motors lower thanthan 5.0T."

Futhermore LRP recommend the use of the LRP#80900 SXX Competition version (the one without the heatsink or fan) for use with 2WD OffRoad. So if I was using this one the ESC would have melted!!! This makes no sense in my estimation.

On the 2nd time it happened I swapped batteries instantly and the motor started up again........ thats why I thought maybe something to do with voltage sensoring etc.......???

[lucas-b4-b44]

The heatsink measured 50 to 55 c with a Fastrax infrared sensor.

[Body Paint]

Originally Posted by lucas-b4-b44

Hi, thanks for posts.....

However this ESC manual it states: "The fan can be mounted on top of the heatsink and should be used for tough applications in hot conditions such as TC Modified or 4WD OffRoad. As a guidelinewe recommend using the fan with motors lower thanthan 5.0T."

Futhermore LRP recommend the use of the LRP#80900 SXX Competition version (the one without the heatsink or fan) for use with 2WD OffRoad. So if I was using this one the ESC would have melted!!! This makes no sense in my estimation.

On the 2nd time it happened I swapped batteries instantly and the motor started up again........ thats why I thought maybe something to do with voltage sensoring etc.......???

That maybe true, but if you overgear the car then the motor and ESC will overheat, no question.

What are you geared on?

Check your instructions and see what lights flashing sequence you have mentioned means, it will most likely be in the trouble shooting section.

[lucas-b4-b44]

Hi, 1st time on 21 pinion 81 Spur 10:03 Ratio as per motor guide, 2nd time with 23 pinion as reccomended by 3 of my model shops.

I have just tried the car again with 23 pinion, was fine for first 5 mins, stopped tested temps = 58 ESC, 56 Motor, 29 Bat.

Let cool down for a bit, happened after 45 seconds, the car went over a 2 inch lip got a slight jarr or bump and got stuck, I picked it up placed on level ground and it wouldn't go. Took off body, starts again instantly. I depressed wires with my hand and the same thing happened: wouldn't start motor. Looked everywhere for possible short or connection problem, absolutely nothing, sensor wire fine no sensor wire connection error lights on ESC.

Error lights on ESC only show after pressing throttle for more than 2 or 3 secs, then it's alternating yellow/red.

Drove for another 3 mins nothing wrong. Went home ran car on bench with wheels off ground, cannot replicate so far? Battery at 7.600v still had 35% in it, so nothing there I think.

I wonder if it could be the motor?

I'm just worried that it's something intermittent that only happens on occaision and if it does go into the shop, it will be sent back to me and happen all over

[Marvin]

Check all your solder joints for 'clean' connections. If you are able to wiggle the wires a bit and the connection breaks, then the soldering needs to be looked at.

[lucas-b4-b44]

I will try a couple of things Jamie from SMD suggested.

I'm going to try this ESC with new sensor wire in the B4 then see what happens, if still an issue:

Will swap this ESC into my B44 and see if it rules out Motor and Lipo.

[DaSloth]

Sensor wire is definetly a good place to start and ill also point to battery connectors as another option in the trouble shooting process. I've seen some people have very weird problems fixed by simply changing their corally connectors!

HTH

[lucas-b4-b44]

OK,

I ran the car with new sensor wire, same problem after 7:30 mins. Then I took body off and pushed the wires about, it started, I pushed them some more then it wouldn't start. Then I noticed that the ORANGE wire was rather hot compared to the rest of the wires. I measured the Blue & Yellow and they were both about 32 celcius, then I measured the ORANGE and it was 76 celcius!, but only over the Corally Connector! The rest of the Orange wire wasn't that hot about 5 or 6 c closer to the connector and a couple of degrees hotter than the other two wires. Now the Orange wire also has a gap where it is soldered to the ESC and when taken apart there seem to be heat scorching on the Corally Connectors.

Now could this whole thing be caused by (I assume this is unusual) unusually hot connector?

(1) Why is this connector so hot?
(2) Could this be the answer: Connector gets very hot & thus looses connection?
(3) If I put on a new connector will it just happen again?

See pics below for further help.

[mattb]

ive had that problem in the past with those type of connectors i think they become a bitt loose or worn over time then you endup with a bad connection which arcs this causes the heat one of my pals said you should replace these type of connectors from time to time.

[bigred5765]

looks like you have answered your own question,why not use a one piece wire from speedo to motor,the gap is nothing more than the silicone sleeve wire moved up,just push it down no problems.

[Rich D]

Originally Posted by bigred5765

looks like you have answered your own question,why not use a one piece wire from speedo to motor,the gap is nothing more than the silicone sleeve wire moved up,just push it down no problems.

What he said ^^

Nice diagram BTW !