MMM (and MMP) cogging/hesitation when warm?

[bdebde]

I have been fighting this problem for a while now, and finally got it fixed this weekend.

I started out with an older MMP and new Neu 1512 in my 1/8th buggy. After driving a few rounds with it I had some intermittent cogging/hesitation problems. I changed both the controller and the motor, because the connectors were different on original setup and new setup. The new setup was a new MMM and a used 1509. After several rounds I had the same problem again! WTF?
I figured out that I could run 5 or 6 minute qualifiers without problems... the problem came about in the 10 minute mains towards the end of the main. I figured it either had to be heat related or voltage related (voltage sag at end of pack). I was not running packs beyond 70% discharge, but the were older 30C packs. I replace them with new, slightly higher capacity, 65C batteries... still no change. I even replaced the receiver to eliminate any other electrical issues, thinking that both motors or speed controls could not have had the same problem.
I put the Neu 1512 from the original setup into another rig... it worked fine, so the MMP must have been the culprit in that setup. I then swapped out the Neu 1509 for a CC1512 in the latest setup... still the same problem. That pointed to the brand new MMM being the culprit in that setup. I had another new MMM but was unwilling to risk it since this was a big race this weekend, and took a known working MMM out of another rig and all was well.
Only problem is, the bad MMM was a new replacement from castle, but had been in the toolbox a while. I hope someone from castle reads this (otherwise I will have to call them) and can help me out. I don't want to have to fork over more money for a replacement for the replacement that never worked in the first place. I should probably also check the other new replacement, as they were received at the same time.

[outlaw]

What Firmware versions are you running on thoses ESC's ?
can you explain the " intermittent cogging/hesitation" a little more

[bdebde]

Latest 1.32 on the MMM, I think... the MMP may have been a bit older, 1.28 maybe. Everything works fine at first, usually ok for 5 or 6 min qualifiers, but towards the end of a 10 min main, if car stops it hesitates to get going (jerks and doesn't take off smooth) and sometimes needs a push to get going. I also notice some intermittent hesitation at low throttle as well.

[magman]

Try resetting the firmware back a bit...I still use older firmware as I had issues with new ones.

[outlaw]

try the 1.24 on the MMM and the 1.26 on the MMP
best working firmware so far

[magman]

Originally Posted by outlaw

try the 1.24 on the MMM and the 1.26 on the MMP
best working firmware so far

+1 I couldnt remember the #'s thanks!

[Bondonutz]

So all my MMM's have the 1.32 and so far seem to have zero issues, would I be better off or would the ESC work better for me with the 1.24 ??

Thx

[bdebde]

My newest MMM's and MMP's have 1.32, my older MMP has 1.28 and the older MMM's are 1.24 (and will not take newer updates without problems). All other new MMM's with 1.32 work fine except the one (also have a new one untried yet). I may give an older firmware a try just to see. Thanks guys!

[magman]

Originally Posted by Bondonutz

So all my MMM's have the 1.32 and so far seem to have zero issues, would I be better off or would the ESC work better for me with the 1.24 ??

Thx

I have an older mmm, 3 yrs, and the newer firmware did not agree with it so i am using 1.24 . It works , just not as smooth as newer firmware.

[bdebde]

Yeah, the older ones don't seem to like anything over 1.24.

[nuz69]

Hi bdebde,

I confirm your statement, it's due to heat. I have noticed the exact same problem when my MMM fan died out during summer. After a few minutes of run, there is a lot of cogging at start, but when the vehicle is cruising no problem.
Check if your fan work correctly or reduce the motor load (smaller pinion, etc...).

NuZ