Motor Temp Spikes

[dure16]

Kraton 6S EXB. MMX8S ESC. 1717 1650KV motor. 20T pinion.

I'm seeing some weird temp spikes in my Castle log. Is it anything to worry about?

Motor temp cutoff is set to 170F, so I'm also curious why the system didn't turn off after exceeding that temp. Maybe it's smart enough to know that spikes happen and only to be concerned if the temp remains high for a certain amount of time.

Thoughts?

 

[Dan B.]

Subbed. Trying to learn as much as I can about castle logs and how to read them.
Doesn’t look like your temps ever got high enough to worry about, though?

 

[dure16]

Doesn’t look like your temps ever got high enough to worry about, though?

Agreed. They look fine overall. I’m just not sure what to make of the spikes, if anything.

 

[dure16]

Has anyone else seen this?

 

[Diem Turner]

Could you zoom in on a one minute segment please? The 40 minute time scale is making a reading of the graph a little difficult. At least trying to compare it to any of my data logs.

Edit: Never mind. Yours does look a little different than mine. Even when adjusted for time scale.

 

[dure16]

Thanks. Here's a close-up view of each temp spike:

 

[Diem Turner]

Sorry man, I can't work out why you're getting temp fluctuations like that. I mean, it's jumping by 60-80°F in the space of 1-2 seconds which doesn't really make sense. But I just pulled up a log from my long deceased MMX8S and it looks a lot more like yours. Not quite as radical in terms of temp jumps, but the general shape is there. What sample frequency do you have your logging set to?

 

[dure16]

Thanks again for looking. Sample frequency is at 2 per second. I lowered it to capture more time in the log.

 

[Diem Turner]

Thanks again for looking. Sample frequency is at 2 per second. I lowered it to capture more time in the log.

No worries bro, my pleasure. Just turds & chuckles, crank the sampling up to 10Hz, just to see what your temp logs look like. It should, at the very least, smooth it out a bit.

 

[Hector_Fisher]

I'd have to think it's just a glitch or something. No way your temps would actually by rising by 150f and then lowering back down in a few seconds. Yeah i'd also suggest increasing polling rate and see what happens. Maybe re-connect sensor wire?

 

[justin080]

I'd have to think it's just a glitch or something. No way your temps would actually by rising by 150f and then lowering back down in a few seconds. Yeah i'd also suggest increasing polling rate and see what happens. Maybe re-connect sensor wire?

hey broi opened also thread, got the same issue

https://www.arrmaforum.com/threads/...rature-and-goes-in-thermal.57987/#post-852770

see in my thread my datalog

and this attached file is the motor before with my xlx2 who reads in realtime without any issue.
i used the 1717 before in mx xlx2 and the curve was smooth af

i think the x8s cant resolute the temp as fine as the xlx2 can do



since nobody uses that motorlogging? and kept their temp cutoff very high, i like it very low.

 

[jkflow]

Those values are abnormal, clean your connections, seems like a bad pin, or it's a bad temp sensor.
For temp, you only really need the average values as temperatures do not jump every second, this seems like an intermittent problem.

Sampling rate, the important values are voltage and current, and 2s sampling is simply not good for any data of value. Need to crank it up to the max if that is what you want to see. A high speed run might only last 2s and would be completely missed.

 

[dure16]

hey broi opened also thread, got the same issue

https://www.arrmaforum.com/threads/...rature-and-goes-in-thermal.57987/#post-852770

see in my thread my datalog

and this attached file is the motor before with my xlx2 who reads in realtime without any issue.
i used the 1717 before in mx xlx2 and the curve was smooth af

i think the x8s cant resolute the temp as fine as the xlx2 can do



since nobody uses that motorlogging? and kept their temp cutoff very high, i like it very low.



View attachment 263220

Dang that’sa lot of current

 

[justin080]

Dang that’sa lot of current

this was the log from

(xlx2)

 

[Diem Turner]

Those values are abnormal, clean your connections, seems like a bad pin, or it's a bad temp sensor.
For temp, you only really need the average values as temperatures do not jump every second, this seems like an intermittent problem.

Sampling rate, the important values are voltage and current, and 2s sampling is simply not good for any data of value. Need to crank it up to the max if that is what you want to see. A high speed run might only last 2s and would be completely missed.

I think that's just how the MMX8S do. This was my MMX8S/1520 combo when it was almost new. My sampling rate was 5Hz and it looks marginally better than the OP's. The purple line is the ESC temp and it graphs that just fine. It would appear that the MMX8S has a wonky motor temp sensor interpreter.

 

[jkflow]

Ok, it's not a bug, it's a feature