Choppy Throttle

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oddworld

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Arrma RC's
  1. Typhon 6s
Can someone help me diagnose throttle issues?

Video showing the issue

History
  1. Just assembled the 1/5 Kraton
  2. Ran through 4 sets of batteries, ran like a dream
  3. On the last set, the throttle started acting up
  4. Let the ESC cool for a few hours
  5. Plugged-in a fresh pack, then took a video of the problem - the throttle does not seem to be stable. It's dropping out
  6. Blown ESC? Blown motor? Other issue?

Rig below



Kit:
Motor:
ESC:
Servo:
Pinion:
Batteries:
Receiver:
Transmitter:
  • Spektrum DX5C
 
Almost seems like an Intermittent BEC Brown Out to me. An ESC issue. Does this happen on the bench without any load? Or only under load?
Check motor leads for a good solid connection. Has this gotten wet before?
Lets see what others say.
 
Happens under load or no load.
Definitely never seen water before. I ran it outside in a dry field.
This car maybe has 30 minutes on the odometer... after building it for weeks.
 
Double check the leads going from the ESC to the receiver.. It acts like there's a cut/tear in one of the leads, like it's just barely getting a signal.
Either that or the connector got jerked out of the receiver port.. barely making a connection..
 
+1
Try above first, then try an ESC reset . If NG, then try a rebind and recalibrate the ESC to the TX. Are the TX batteries fully charged? Probably is being new and all. But double check.
Other wise may be the BEC circuit. Brown out. A Defective ESC?
Does it happen whether you are Steering and throttling both together or just with the Throttle alone? Does Steering servo work fine, alone by itself , not stuttering?
 
Last edited:
Only throttle - steering is fine.
Agree it's a good idea to check leads. Maybe either (1) ESC to motor or (2) TX to ESC (which would be really weird, but possible).
 
SrC said:
+1
Try above first, then try an ESC reset . If NG, then try a rebind and recalibrate the ESC to the TX. Are the TX batteries fully charged? Probably is being new and all. But double check.
Other wise may be the BEC circuit. Brown out. A Defective ESC?
Does it happen whether you are Steering and throttling both together or just with the Throttle alone? Does Steering servo work fine, alone by itself , not stuttering?
Click to expand...

Quick update on the matter. Mind lending a hand in diagnosing the problem?

I confirmed all connections look good, unplugged and re-seated them. I factory reset the ESC. The problem continues. I did a very slow test drive in the backyard on 6S for 3-4 minutes. The ESC and motor reached 140F. The motor wires were unusually warm. That shouldn't happen because there's massive 40MM Delta fans cooling everything on an independent 3S battery.

I'm using the Sanwa M17 Transmitter and RX-493 Receiver. Any settings on that I might need to tweak?

I am really scratching my head here. Any help is appreciated.

XYNPvTZ - Imgur.jpg


MvdPolH - Imgur.jpg


SEPSHZo - Imgur.jpg
 
From what you're describing.. could be a bad circuit in the ESC.. there's some kind of shorting going on..

Have you tried a different ESC..?
Just to confirm/prove that is not the issue.
 
Tex Koder said:
From what you're describing.. could be a bad circuit in the ESC.. there's some kind of shorting going on..

Have you tried a different ESC..?
Just to confirm/prove that is not the issue.
Click to expand...
I don't have another ESC, I would need to buy a new one. How confident are we that ESC is the issue, and not motor?

I have another data point:
  • I removed Sanwa receiver
  • I installed Spektrum SR315 and ran on DX5C
  • After 3 minutes of running again, it got hot again
  • Green light flashing on ESC, meaning thermal / overheat protection kicked in
  • Temps read 155F on the ESC and 160F on the motor
Buy another ESC + Motor combo? Same thing again? 5687-1100kv Motor + MAX5?
 
140F is not tragic for the motor to be honest. 160F is not great at all.
If that is where it peaks. But the ESC going Thermal Cut with External temps at 155F is NG. Internally Mosfet Thermister is seeing 221F +.(n)
I feel those connectors got to go to begin with. Get some QS8's. Could be the source of high temps along the wires. Not the primary issue however.
The Radio/Rx has nothing to do with heat issue's.(n)
Do you have the HW programmer or BT adapter to get into the ESC parameters? >>>>>>>>>>>If not, get one.
Do you have the latest F/W update? (Again, need the programmer)
Max5 has an Optional Thermal protection setting for 257F. Default is 221F. Did you see this yet ???? Max5 does run normally hotter than some other ESC's. Most are set for a 212F thermal cut. You can also try and disable the Thermal cut temporarily, and monitor closely with your temp gun. See where it peaks or spikes. Carefully watching it as temps spike.
Try upping Thermal Cut to 257F. If you have not already. And Evaluate.
What exact gearing are you running?
Could be a bad ESC, a dud or even the motor.
:cool:
 
Last edited:
SrC said:
140F is not tragic for the motor to be honest. 160F is not great at all.
If that is where it peaks. But the ESC going Thermal Cut with External temps at 155F is NG. Internally Mosfet Thermister is seeing 221F +.(n)
I feel those connectors got to go to begin with. Get some QS8's. Could be the source of high temps along the wires. Not the primary issue however.
The Radio/Rx has nothing to do with heat issue's.(n)
Do you have the HW programmer or BT adapter to get into the ESC parameters? >>>>>>>>>>>If not, get one.
Do you have the latest F/W update? (Again, need the programmer)
Max5 has an Optional Thermal protection setting for 257F. Default is 221F. Did you see this yet ???? Max5 does run normally hotter than some other ESC's. Most are set for a 212F thermal cut. You can also try and disable the Thermal cut temporarily, and monitor closely with your temp gun. See where it peaks or spikes. Carefully watching it as temps spike.
Try upping Thermal Cut to 257F. If you have not already. And Evaluate.
What exact gearing are you running?
Could be a bad ESC, a dud or even the motor.
:cool:
Click to expand...

I have this Program Card - it allows me to change settings, but not update firmware.
Gearing: 27T pinion (Mod 1), and the default 47T Spur. Does that look correct for this vehicle?

I really don't think raising the limit will solve it - the ESC nearly cooked itself in a matter of 3 minutes with two massive fans attached. I drove very slowly in the backyard - no more than 5 MPH. Something is wrong.

How could I test whether the problem is attributable to (1) ESC, (2) Motor or (3) both? Is there a decent way to test the motor to confirm it is functioning correctly? What about the ESC? I've got a Fluke multimeter.
 
HMM...... yeah somethig is wrong. I agree. Gearing is fine for that 1100kv motor.(y) Could go a larger Pin.

I also use that same prog card. But also use the HW BT adapter/ Phone App. with my XR8 Plus. It will update F/W.
I would try flashing the Firmware first. Need to rule out a software issue first. Otherwise it could be a Hardware failure.

Also Try this:
https://www.arrmaforum.com/threads/testing-your-blx-esc-that-appears-bricked.22054/

Also, Disconnect the Pinion and run the motor without load on the bench. Should spin smooth and quietly. See what you get. Take the motor out and disassemble it. Look for burned stator and/or seized BB's. Frayed armature ect. I doubt it is the motor, but can't rule this out. Make sure to place a drop of Oil on each BB while you are in there, if all looks good. Preventive maintenance while the motor is opened.
I use my Turnigy BLX Motor Analyzer to check my motor's Phase Timing, RPM's and BB's , when new and when I have issues. Maybe overkill for some at aprox $100.
I would try and up the Thermal cut limt to 257F. Not as a fix, just to see if it will thermal cut. Could be a mosfet thermister failure.
Does the ESC get hot and act similar on the bench, off it's wheels? ( or wheels removed)
Make sure the drivetrain is not binding anywhere, if you haven't checked.
Roll the rig with the Pinion disconnected, does it roll freely?
Just some ideas.
Good luck.:cool:
 
Last edited:
SrC said:
HMM...... yeah somethig is wrong. I agree. Gearing is fine for that 1100kv motor.(y) Could go a larger Pin.

I also use that same prog card. But also use the HW BT adapter/ Phone App. with my XR8 Plus. It will update F/W.
I would try flashing the Firmware first. Need to rule out a software issue first. Otherwise it could be a Hardware failure.

Also Try this:
https://www.arrmaforum.com/threads/testing-your-blx-esc-that-appears-bricked.22054/

Also, Disconnect the Pinion and run the motor without load on the bench. Should spin smooth and quietly. See what you get. Take the motor out and disassemble it. Look for burned stator and/or seized BB's. Frayed armature ect. I doubt it is the motor, but can't rule this out. Make sure to place a drop of Oil on each BB while you are in there, if all looks good. Preventive maintenance while the motor is opened.
I use my Turnigy BLX Motor Analyzer to check my motor's Phase Timing, RPM's and BB's , when new and when I have issues. Maybe overkill for some at aprox $100.
I would try and up the Thermal cut limt to 257F. Not as a fix, just to see if it will thermal cut. Could be a mosfet thermister failure.
Does the ESC get hot and act similar on the bench, off it's wheels? ( or wheels removed)
Make sure the drivetrain is not binding anywhere, if you haven't checked.
Roll the rig with the Pinion disconnected, does it roll freely?
Just some ideas.
Good luck.:cool:
Click to expand...
I read the post you linked above. It seems like MOSFETs on the ESC sometimes "fail closed" - meaning that a multimeter's continuity test can be helpful in understanding whether problems exist. I'll give that a try.
 
ESC's can fail due to MosFet Over Temps ( probably in your case)
Can fail at the BEC circuit and Power Regulator also.

FWIW, I disected several bricked Legacy BLX185 ESC's. I found that the Heatsink is not adequately flush and with adequate HS compound against the 3 MosFets. I found gaps on a few of the Mosfets. Contributing to overtemps.
QC causing Temp issues. With Little/less Thermal transfer of Heat from the MosFets to the HS. I could see how if yu got a bad one, Temps can skyrocket no matter how many fans you use. Temps will Splike very fast. Fans won't control it effectively. HS needs to be firmly mechanically attached well to the MosFets.
I also noticed corrosion below the HS on the PCB/Mosfets. A sign that the Silicone Potting did not seal the ESC well enough, so these ESC's are not truly Water proof. Just food for thought.
 
Last edited:
I've purchased and connected a LCD programmer. Can anyone verify whether this is the latest firmware for the MAX5? The program is a little janky.

max5.png
 
Old Thread: Hello . There have been no replies in this thread for 90 days.
Content in this thread may no longer be relevant.
Perhaps it would be better to start a new thread instead.

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