MM hesitates/stammers on slow take off. Where should I start

[Gee]

FLM Maxx, MM, HV4.5, 70/14, on 4s. Since the firmware and software update the motor no longer coggs. There is an annoying screeching or straining (hard to put into words) noise when taking off slowly. Almost like it's trying to turn over.

Any recommendations for setting that may help this. Maybe a baseline recommendation and what to mess with first would be a lot of help. I know the motor is sensored and the esc isn't. So may not be able to eliminate the problem all together. It's an awful sound, sounds sick so even a small improvement gonna help.


Punch Control %
Starting Power
Timing
anything else?

Thanks.

[sleebus.jones]

I think your biggest problem is that you're using the wrong motor for this type of application. With that voltage, you're looking at 60,000 rpm+, which is really high. It's also a short can motor. I've found that even long can motors aren't enough for a MT, so a short can isn't going to work well at all.

I'd say that your best bet is to gear down as far as you can.

[Gee]

I think it's the right one. It's the Novak HV4.5 motor that NOvak made for the e-maxx. I got it geared at what Novak has recommended but that's with thier esc. If I can't get the software improve it. I'll gear it down a bit. The MM is the only esc I have for them at this time. Both my HV esc have been sent back to Novak for replacement. The mm is actaully doing a great job with the motor. It's seems to be running cooler and with longer run times then when I have the Novak HV esc in it. I found the manual for the mm so I got a better idea of what to try.

Oh, your probably thinking I'm using the velocity 4.5 motor that comes in a 540 can. Instead of the High Velocity 4.5 motor. The HV4.5 and 6.5 are 550's.

Thanks.

with the software update , i still had some problems, although i think mine was caused by gearing, i spent the better part of an afternoon and got it to start ok in my truggy, but a smaller pinion would have helped

i would suggest tring diff. settings on the mm and see if it helps, its a pain , but with your gearing it shouldnt be all that bad, try diff. timing and start powers

[BrianG]

Something simple, but the FAQ at Castle states that the symptoms you describe can be caused by batteries that aren't up to the task. If this is the issue and battery replacement is infeasible, it may help to increase punch control to something like 50%+. This may help limit the huge current surge somewhat making the batteries work a little less.

[glassdoctor]

I have barely done anything with the new firmware, but I noticed it is a lot noisier than before at startup/crawling speeds with my 1512.

The screeching you have may just be "normal"... maybe it's just worse with the novak motor?

Edit: You said it no longer cogs... but the thread title makes it sound like it is. It makes a bad noise, but does it take off smooth and strong or does it cog?

[Gee]

It's not cogging. Cogging to me is the violent lurching forward and stopping and so on. This starts to move the truck slowly screaming for a little bit then the sound is gone and no problems. Performs great really. The noise is an irratent I guess more then a performance issue. It's something that can be lived with. Unlike the ex which was a screeching/screaming noise at all the time. Come to think about it I guess by my definition you could say she also cogged at me too.

It's probably just the way the two are gonna work together. It's a major improvement from before the firmware. The batteries I'm using are decent and it does it on either set. Use TrueRC 6400's and the MA 6000's. Don't have the noise with the MM/Neu 1515 1y setup.

I'll guess I'll first try to set the mm to it defaults and try moving the setttings one by one for start power then do the same with motor timing. See if I can find a spot that it does it less. The gearing is a good speed for it and worked well with the sensored esc. Don't really want to take away any of the top speed but if that what it takes. I'll try a lower setting if the software doesn't improve it. Thanks for the inputs.


Do you think I need to recalibrate the esc/controller each time I try a different setting?

[BrianG]

OH, if it's just the noise, that's no big deal. I wonder if Castle changed the startup frequency with the new firmware? That would change the way it sounds...

[glassdoctor]

Then it's probably just the high frequency noise from the esc "sensing" the rotor positon (using small current pulses and measuring back emf or something like that), with that motor being especially loud. The noise stops at a certain speed, or after a couple seconds, right?

My Neu definitely has more noise than before but it's not bad... the Novak must be pretty bad.

Something is definitely different, and whatever they changed it works better.

[Mister-T]

Sorry, it little of topic but,

There is ton's of document about brushless stuff on ST website. It's technical but most people with few base on electricity can understand a large parts of the data.

http://www.st.com/stonline/books/pdf/docs/7438.pdf
http://www.st.com/stonline/books/pdf/docs/10401.pdf

The most interesting for us is this,
http://www.st.com/stonline/products/...e/an/13196.pdf
it's not really a marketing documents, it's seem that ST microcontroller can pretty much offer startup close to sensored motor on sensorless motor o_O

[johnrobholmes]

The stator of the Novak motor is singing along with the PWM that Castle uses. The new startup routine is a bit louder, but much smoother. I have been hassling them for quieter startup for some time, but it will probably take years for them to get that taken care of.

[lincpimp]

That is just the noise that is designed in to strike fear in the hearts of nitro users. Once they experience the raw power and speed of electric it will be ingrained in their minds.

I have also noticed the noiser startup, but it works better, so I am not complaining!

[Gee]

Originally Posted by lincpimp

That is just the noise that is designed in to strike fear in the hearts of nitro users. Once they experience the raw power and speed of electric it will be ingrained in their minds.

I have also noticed the noiser startup, but it works better, so I am not complaining!

You guys pulling my leg again? I believe linc but the rest of you. IDK motor and esc talking in frequencies that normally dogs only hear. But know all of sudden we can here them too? That scary not only for a nitro guy but a electric too!

But seriously thank for chiming in. Some smart & experienced users in this forum and it great everyone shares what they know.


Glassdoctor.
Yeah it does stop after it gets moving. The warmer the setup gets the louder it seems and it becomes harder to get moving. The esc stops talking and starts yelling at the motor. Tried a bunch of different setup in the software. Going to start gearing it down to find out how low it will have to go to run without the noice. I still have a HV6.5 motor I was going to put in it to see if the same happens with it.

I have noticed the revo does it just a little bit sometimes. I have it 54/26 with the Neu1515 1y. I didn't notice it until after the maxx started to do it.

[lincpimp]

Are you running the upgraded firmware with the neu too?

The 2 pole motors seem to be quiter on startup than higher pole counts. It is a totally different startup routine from the old firmware. Seems like it switches at a reasonably low rpm to different frequentcy. I will actually say that my plett max (4pole) runs smoother than my hacker motors with this revised software. Not sure why, but it seems like the mm likes the higher pole counts better, depending on gearing etc.

I have a novak 6.5 that I would like to try on 3s in my ls10. Just need to wire it up and give it a try. I was waiting on the 5mm shaft upgrade first. Just broke a c50 maxx shaft and would prefer not to do that again!

[Gee]

Hey did notice a post here. Yeah, got the new software and firmware on the mm controllers. Does it matter to the motor if you are running a sensored ESC or not? Not sure it that is what I am asking. What is the difference between a sensored motor vs not sensored?