Sensored MMP Stuttering Badly. Ideas?

[Tommy R]

Here's the specs:
- Brand new Castle Mamba Max Pro
- Novak 18.5t crawler motor
- 3s

It's running sensored and I've tweaked a variety of software settings, but it stutters very, very badly on start up. They say a picture is worth a thousand words.....well, here's a video:

Brushless Motor Stuttering - YouTube

Anyone have any suggestions? I've tried fully sensored, Smart Sense, and all kinds of throttle curves to no avail. It doesn't seem to act like it's merely unsensored. It seems like something else is going on. And FYI, the entire driveline spins very freely, no binding at all.

Any suggestions?

[Checkitout0125]

I just had the same issues out of my MMP and tekin 13.5t. I believe if turned out to be nothing other than the sensor wire not being seated all the way. You can look at my thread and replies on the thread Tekin 13.5t just cogging or bad MMP. I have not had time to mess with it yesterday so I am not %100 saticfied that it is not a bad sensor just yet. Hope this helps.

[Checkitout0125]

I just watched your video. I have not watched the motor sinse its under the truck assembled. Mine doesnt have the squeeling sound but it does nothing when you nail throttle and then jumps a few times.....then takes off. Sounds like we have the same issues though.

[Tommy R]

Initially it was worse and I noticed the sensor wire wasn't seated. In the video, however, the wire was completely seated. Not really sure what to think. But as I gradually squeeze the throttle, the noise starts. More throttle will get it to stutter as seen in the video. More throttle will finally get it to start spinning, but it spins too fast for crawling. It's getting pretty frustrating.

[neillarson]

I had the same problems Tommy in my Wraith, 5 people told me 5 different ways it was that I didn't know how to use castle link to set it top, and that was after 5 people told me I didn't have the sensor cable plugged in. I am now very happily running on my BR-XL Waterproof and a HH 27T.

[JeremyH]

I had very similar problems with the sensored brushless setup in my wraith....turns out I did not have the motor leads soldered to the proper connections (A,B,C).

[Tommy R]

Aw, don't tell me that, Neil! I am finally getting the wheelspeed I've been lacking and I was getting excited about the Wraith again. I really don't want to go back to a brushed setup if I can help it. I like the timing advance feature of the brushless stuff.

I should also point out that I'm now running a BEC to power the steering servo. It didn't make any difference, though. Someone on another forum suggested an older software revision (1.26 if I recall). I've also got other sensor wires which I can try.

[Tommy R]

Originally Posted by JeremyH

I had very similar problems with the sensored brushless setup in my wraith....turns out I did not have the motor leads soldered to the proper connections (A,B,C).

Thanks, Jeremy. I'll double check everything is plugged in properly when I head home for lunch.

[JeremyH]

If it's not that, then I'd say a bad sensor wire. I have had a bad one before and it acted just like that...

[Tommy R]

Originally Posted by JeremyH

If it's not that, then I'd say a bad sensor wire. I have had a bad one before and it acted just like that...

Oh, really? So it'd stutter when starting, but smooth out more once it's spinning?

[Checkitout0125]

From what I have gathered with mine having same issue currently is that a sensored motor running sensorless will "cog" so bad on startup that there appears there is something wrong when compared to a sensorless only motor. My bet is on a bad sensor, poor sensor connection, or the sensor port on the MMP. Hope it helps.

[WraithCrawler]

It's either a bad sensor wire or bad sensors. I had the same problem, but my was bad sensors. (My own fault. Melted one.)

EDIT: Once it is fixed, you will know immediately. I have the same setup with the 21.5T. With tiny amounts of throttle input it applies torque VERY smoothly. (16/87 gearing)

[D_Frawg]

I also has an issue like this once make sure you A wire on ESC is to a terminal on motor and b-b c-c and be sure the sensor wire is seated. The second time I had this happen I had bought an eBay motor and a sensor wire was loose inside the motor can I just touched it with a hot solder iron and it was fixed.

[Meatwad]

I called novak a couple months ago asking the difference between the 17.5 and 18.5, apparently the 18.5 has a bigger rotor for more torque. Also a sensor board that is specific to novak controllers(?). I then asked how an 18.5 would act with an mmp, the guy said they don't have any to try and won't lol. So I got a tekin pro4.

Edit: after curiosity and more digging, the difference is that the board allows for instant fwd/rev which apparently novak controllers have a prob with. I'm concurring with either a bad sensor board/wire.

[Tommy R]

When y'all refer to bad sensors, are you referring to sensors on the motor or the ESC? Evidently, I don't know as much about brushless junk as I thought!

[Charlie-III]

Originally Posted by Tommy R

When y'all refer to bad sensors, are you referring to sensors on the motor or the ESC? Evidently, I don't know as much about brushless junk as I thought!

Sensor inside the motor, it's a small PC board usually where all the wires run into the motor.

[Tommy R]

Originally Posted by Charlie-III

Sensor inside the motor, it's a small PC board usually where all the wires run into the motor.

Great, thanks! At least it looks to be cheap/easy to swap out.

[JeremyH]

Originally Posted by Tommy R

Oh, really? So it'd stutter when starting, but smooth out more once it's spinning?

When I had the wiring messed up it would just cog really bad. With a bad sensor wire, it acted like an unsensored motor....

[jkwrangler08]

After looking at the vid, I gotta believe it's the order of the 3 main motor wires (ABC). Check the labeling on the ESC and insure they are in the proper order on the motor. I'm guessing that if you pulled the sensor wire it would act pretty much the same..

[hoghead5150]

ya got your wires hooked up wrong brother! look at the motor. there where the motor wires are on the NOVAK sticker there are A,B,C terminals. red to A, black to B, white to C. on my ballistic motor the red wire goes to the K in NOVAK, the black in middle, white to the N in NOVAK. yours in the video are in the wrong sequence.

pull connectors apart, and hook them up right. you don't have to resolder if you don't want to, but i would just so you can keep it straight!