Calling all the gurus!!!

[DLK83]

I'll try to make this short and accurate:

Xmaxx; running a TP 5840s 1150kv with a MMX8S, if you try to full throttle stab it, it has a horrible hesitation/cutout; ease into it, it's fine...
Fast forward to this weekend, switched out the motor to a Castle 1717 1260kv, and now on a full throttle stab, it has a similar reaction, but no where near as bad, more like a quick studder that it will pull through...
My thought is something is wrong with the esc, the TP motor is amp hungry making the problem more prevalent, whereas the Castle motor is not pulling as many amps and the problem is less noticeable...
My question is: anyone experienced the same problem? I have another MMX8S I could try, but is has a cap pack soldered on and if I pull the esc out of the Xmaxx, I feel like I might as well just replace it, it is 3 or 4 years old, has been hot,been submerged, etc, it could just be worn out... thanks to any and all responses!!

 

[dure16]

My first guess would be weak or defective batteries.

 

[DLK83]

Brand new gensspammer basher batteries, 6800mah that have good ir readings and run fine in other rigs.... BUT, I have plenty of others to try and I will tonight just to rule it out, keep the suggestions coming guys! Thx dure16

 

[MFM]

Sensored? Sensorless? I’ve had similar w a bad receiver w no cap pack running several fans….

 

[DLK83]

Sensored, and funny you should say that, the rx died this weekend while bashing so I hoped that was the problem but I put a new/used rx in and still does it... also, it's not even close to being over geared just to rule that out... and I run my esc/motor fans off a separate small 3s so the only thing pulling from the bec of the esc is the servo

 

[MFM]

Sensored, and funny you should say that, the rx died this weekend while bashing so I hoped that was the problem but I put a new/used rx in and still does it... also, it's not even close to being over geared just to rule that out

Aftermarket servo? Rx? Traxxas?

 

[dure16]

Brand new gensspammer basher batteries, 6800mah that have good ir readings and run fine in other rigs.... BUT, I have plenty of others to try and I will tonight just to rule it out, keep the suggestions coming guys! Thx dure16

Okay. Can you post the data log here?

 

[DLK83]

Aftermarket servo? Rx? Traxxas?

Promodeler servo, Spektrum sr315 rx and DX5 Rugged radio

 

[RC-Dude]

Check your timing.
That horrible cutout basically means the ESC gives energy to the motor but it will not turn. That energy needs to go somewhere and turns to heat. That may fry your ESC.
Turn down your punch after checking the timing. But first do the timing and then only after driving the punch. Don't change two things at a time.

Sorry just reading again - had in mind is was a Castle ESC. Hobbywing no timing change possible.
You might want to change the three phases with each other. And see if it removes the stuttering. There is this weird thing if the three phases (the wires between ESC and motor) have the "wrong" length the motor may stutter. It does happen in EDF jets where the 3 phases at times are longer due to distance between ESC and motor. Longer cables for the phases are no problem at all but there may be this "rocking up" of the phases due to "wrong" length that might result in stutter. I've only known this to happen with long phase cables in EDF jets. Problem is solved by changing length of them.

Solder 3 extra cables to change the length between ESC and motor with plugs/sockets and try if it makes a difference. I think it's worth trying. Alternative is to dump the ESC.

 

[DLK83]

Okay. Can you post the data log here?

Ooof, I can try, I'm about as tech savvy as a bowling ball, but I'll try

Check your timing.
That horrible cutout basically means the ESC gives energy to the motor but it will not turn. That energy needs to go somewhere and turns to heat. That may fry your ESC.
Turn down your punch after checking the timing. But first do the timing and then only after driving the punch. Don't change two things at a time.

Timing is at default, 10° I believe, start power is set to low

 

[LibertyMKiii]

Pulling the data logs might tell you a lot, but I'd be willing to be you are hitting low voltage cut off during high amperage needs.
I ran some gensacearespammers lipos with my XLX2 and they voltage sagged really bad. They had good IR readings, but that is not the full story on amperage delivery abilities.

 

[MFM]

Promodeler servo, Spektrum sr315 rx and DX5 Rugged radio

That servo can be robbing low end power, try a $7 capacitor

 

[DLK83]

Pulling the data logs might tell you a lot, but I'd be willing to be you are hitting low voltage cut off during high amperage needs.
I ran some gensacearespammers lipos with my XLX2 and they voltage sagged really bad. They had good IR readings, but that is not the full story on amperage delivery abilities.

Understood, I'll try some different batteries tonight... if it's not batts, where would you go next? Try a different esc?

That servo can be robbing low end power, try a $7 capacitor

I ran that servo off a small stand alone 2s battery like Promodeler recommended, still did the same thing... I've been chasing this issue for a long time, the only thing I haven't tried was a different esc...

 

[LibertyMKiii]

Understood, I'll try some different batteries tonight... if it's not batts, where would you go next? Try a different esc?

Next I'd pull data logs and see what it is doing using the castle link USB

 

[MFM]

Castle tech support has been superior to others. I’m sure you could call em up and they could walk ya thru it. They helped me w my mmx 1515 2200 set up in my senton6s

 

[Ron Burgandy]

I had similar experience with my XLX2
Turned out it was crappy soldered bullet.
Cleaned it up , new connector , better soldering and never had the problem again.
I’m no guru
And your probably WAY better at soldering than myself…
Just thought I’d mention to maybe get in the GURU club !!!

 

[DLK83]

I had similar experience with my XLX2
Turned out it was crappy soldered bullet.
Cleaned it up , new connector , better soldering and never had the problem again.
I’m no guru
And your probably WAY better at soldering than myself…
Just thought I’d mention to maybe get in the GURU club !!!

I never considered that, but it's now on the list! Here's what I can say though,as I just got done driving the truck: it's not batteries, does the same thing with 2 different, known good sets. It also doesn't do it in reverse. And another thing I realized, if I only use the very first portion of the throttle(let's say first %15), it snaps hard like it should on a full pull, and it's very hard to sneak up on the throttle in forward, it's like it goes from 0 to get some immediately... could this be a esc or radio setting issue?

 

[DLK83]

This is all new to me, so tell me what else you want pics of and how to navigate the log screen lol

Here's Voltage and Ripple

 

[dure16]

This is all new to me, so tell me what else you want pics of and how to navigate the log screen lol

View attachment 323010
Here's Voltage and Ripple

Those are some pretty big dips in voltage, which tells us that your batteries can’t handle the demand. I would get some bigger capacity, higher quality batteries.

 

[DLK83]

Those are some pretty big dips in voltage, which tells us that your batteries can’t handle the demand. I would get some bigger capacity, higher quality batteries.

It's not batteries, it does the same thing with 3 different sets/2 different brands, 2 of those sets got used YESTERDAY in a converted 5T with an XLX2/2028 combo that ran like a scolded dog...
Let me also share this, which I probably should have put in the first post, this EXACT esc/motor ran fine in the truck at one point