Timing Changes & "Boost" on Brushless Motors

[Tommy R]

Hey folks,

I'm still pretty new to brushless motors and have a question. Right now I'm running a Novak Crawler 18.5T in my scaler and it's controlled by a Mamba Max Pro (on 3s). I only recently learned about timing advance settings or "boost" that is controlled by my ESC. So I experimented with adding ~22 degrees and it comes in at a pretty high RPM so it won't affect my low speed crawling. So far, I'm liking the added wheelspeed at higher RPM.

But I just learned that my motor comes pre-set from the factory with 30 degrees of timing. Should the timing be reduced to zero if I plan to run any advance? Novak's manual (http://www.teamnovak.com/tech_info/i...tor_timing.pdf) says not to, but is it safe to run additional timing on a motor that has 30 degrees of timing already?

Can someone help shed some light on this, please?

[Stregone]

I'd leave it. Brushless motors need a nice chunk of timing to run well, they don't like to have zero or very little timing(the zero mark on the can is probably not the real zero point as well).

[concretejungle]

welcome to "cheat mode"!!! Yea, i was wondering the same thing and from what i've read and been told, leave the motor as is and mess with the ESC. When i ran mine with a ton of advanced timing (thru the ESC) my esc and motor would get hot. I know Erik Delux has been running a fan on his motor because he runs cheat mode all the time on his losi CC.

[dystance]

Been experimenting with settings on my Mamba Max pro on 2s. I run the cheat on sensored only mode and the setting at 30 for more open none technical terrain - With this setup and a 17.5 brushless motor my Wraith is faster than stock and as fast as I would want it with the terrain I drive. It even crawls decent. I have to keep an eye on the temps with this setup, but if the fast sections are mixed in with some slower sections the temps stay acceptable. Perfect for a race situation. In more tight and technical spots, i have a crawler setup that uses the smart sence setting with a timing advance of 15. Motor stays just warm and it has better control and decent wheelspeed ( slightly slower than stock ). Combined with the punch control and the drag brake, the flexability of the MM Pro is great.

[JohnRobHolmes]

I typically run the motor around 6 degrees of mechanical timing advance to keep the low speed efficiency and torque per amp at the peak possible. Then let the controller add electrical timing as it spools up for better top speed and power. This will keep the motor running coolest if you don't get on the throttle.

The mechanical zero is rarely a real zero anyway, it would take some special equipment to get a true zero time to the motor. The closest you could get with just an amp meter would be to adjust timing to the lowest no load amp draw. Then add 5 to 10% amperage in timing advance for a good all around setting.

[Tommy R]

Thanks for the input, y'all. Tonight I was messing around and realized my truck is a LOT faster in reverse than in forward. I checked my controller and it appears the trans. configuration I'm running required that I reverse the throttle positions. I'd forgotten about this since it's been so long since I'd set it up.

I can't find the info. on Novak's site, but how do I properly reverse the direction of a brushless motor? It would appear the timing advance is only in one direction....and currently in my truck, it's backwards!

[Tommy R]

BTW, I tried reversing the programming in the software (which required a change back to "NORMAL" on my transmitter) and the issue persists even after re-calibrating. Reverse is still significantly faster than forward.

[Stregone]

You need to reverse the timing on the motor endbell. Not sure if that is possible.

[JohnRobHolmes]

What color light do you get on the mamba in forward locomotion?

[Tommy R]

Originally Posted by JohnRobHolmes

What color light do you get on the mamba in forward locomotion?

It's red with the tx in "NORMAL" for throttle position and "REVERSE" in the ESC programming. I suspect forward would be green if I reversed the tx and ESC settings, but would need to verify.

[JohnRobHolmes]

Yes, that is right. What you want is the light green under forward throttle, so reverse your TX. Then reverse the motor direction in the ESC programming to get the vehicle going in the right direction. That will get you on the right track.

[hotwheels000]

Is this for your Wraith ? You can also switch the ring gear to the other side of the pinion to get the truck to move the proper direction with the Green light.

[Tommy R]

Originally Posted by JohnRobHolmes

Yes, that is right. What you want is the light green under forward throttle, so reverse your TX. Then reverse the motor direction in the ESC programming to get the vehicle going in the right direction. That will get you on the right track.

I now have green light in forward on my MMP, red for reverse. ESC programming is "NORMAL" and tx throttle is set to "REVERSE".

Originally Posted by hotwheels000

Is this for your Wraith ? You can also switch the ring gear to the other side of the pinion to get the truck to move the proper direction with the Green light.

Nope, my Toyota.

I spoke to Charlie of Novak and he suggested I go to zero timing and it should get forward/reverse equal. Well, I followed his instructions and did that, but it's now MUCH, MUCH faster in reverse than in forward. It's like the timing is only being added in reverse or something. I'm so confused now.....

[Tommy R]

So I e-mailed Novak and asked how to reverse the direction of the motor and/or what I should do in my situation. Charlie replied back promptly and told me to set my timing to zero. He told me I could easily do this by aligning the sensor port with the power leads. The three endbell(?) screws will also align with the three screws that come through the backside of the can. This picture that Charlie sent me shows zero timing.


So that's what I did on Friday. To be safe, I also set the programming for my MMP to zero timing to keep things simple. Unfortunately, the reverse speed is still WAY faster than forward....maybe even moreso! It's exceptionally frustrating and Charlie is thinking it's an ESC issue, not the motor.

The green light is showing for forward and red for reverse, so that is set properly it would appear. Endpoints were set at 100 fwd/rev and calibrated upon starting up the ESC. Lights are solid at WOT in fwd/rev. Honestly, I'm not sure what to do here. Am I going to be forced to rebuild my truck with the motor/tranny flipped the other way because there evidently is no way to reverse a brushless motor? I really, really, (let me emphasize) REALLY do not want to do that.

[concretejungle]

Charlie will take care of you. Keep trying and once you get it right you will be very glad.

[Tommy R]

Originally Posted by concretejungle

Charlie will take care of you. Keep trying and once you get it right you will be very glad.

Charlie has been great to deal with! I just hope I/we can finally resolve this.

[skid]

Try rotating the end bell clockwise some more.

[EeePee]

Yeah, just rotate the endbell until you get even speeds forward and reverse, or a little faster going forwards. And make sure to keep a keen eye on motor temps for a while, then add in some boost if all is well.

[Tommy R]

Originally Posted by skid

Try rotating the end bell clockwise some more.

Originally Posted by EeePee

Yeah, just rotate the endbell until you get even speeds forward and reverse, or a little faster going forwards. And make sure to keep a keen eye on motor temps for a while, then add in some boost if all is well.

That kinda scares me. And the reason is because it seems my motor is now running hotter after reducing the timing closer to zero. Shouldn't it be running cooler with less timing?

[Erin]

Can you just switch two motor wires like you can with castle non-sensored motors? Not sure if that makes a difference with yours being sensored.