MambaMax ESC quirk - Page 3 - RC-Monster Forums

Serum · 11.14.2006, 06:08 PM

It where flightpowers, those are the speedrecord cells.. :p

captain harlock · 11.14.2006, 09:02 PM

And 8s of them, too?
Nitro Tc3 uses 8s= 130+mph
The dirt oval rig uses 8s, too. = 160mph

lydiasdad · 11.14.2006, 11:26 PM

My mm also does this. It's in a touring car, hard-wired running a fiegao 8s on 6 cells. I noticed it on my first run.

BrianG · 11.14.2006, 11:34 PM

Wow! I thought I was the only one when I started the thread since the few replies I got led to dead-ends, but it seems like this is quite a widespread issue after all.

lydiasdad · 11.14.2006, 11:49 PM

Yeah, the problem is there. Not a huge problem, but they definitely should not be ignoring the issue. Maybe not a lot of people have not reported the problem. I noticed it as soon as I ran it but I just took it as you put it, a "quirk".

glassdoctor · 10:45 AM

Serum, I'm thinking the flightpowers and the kokams are the same cells? I've been told that more or less but don't recall who or where. What's interesting is that we hear raving reports about both being the greatest cells ever made. :)

lydiasdad: Which "glitch" do you have? There are at least 3 different issues mentioned in the thread...

1. BrianG's glitch: cogging when going from reverse to forward

2. Glass's glitch: hiccup when gently coming back on throttle while the car is still moving

3. 1/8 vehicle: basic cogging at start up.

IMO, #2 is by far the most critical issue and the biggest problem, because it has a big impact in using the system for racing.

#1,3 are issues and it would be nice to see fixed, but they don't prevent anyone from using the system and it's not a big problem even for racing. I guess #3 can be a problem if you crash a lot and have to get going from a standstill several times a race... but then this is using the MM out of spec and with aftermarket motors. I think CC will improve on #3 with future software releases.

#1 and #2 I don't know.... I hope they take the time to work out these...

lydiasdad · 10:31 AM

I'm not exactly sure. I only have the problem when the vehicle is at a standstill. So I guess it's problem 1. Mine also does it intermittently as BrianG described. I actually have not payed much attention to it. I will run mine to see specifically when it does it.

BrianG · 11.15.2006, 10:46 AM

GD: While going from reverse to forward (#3) doesn't apply to racing, I think the cause is the same as the other two scenarios. It seems to be a matter of rotor position sensing and how the MM software deals with it. I haven't had the problem where it coggs coming out of a turn, but as you said, that might be because I'm not a skilled driver and simply don't notice it. Or it might be more prevalent on a heavier vehicle where the ESC is running closer to it's max rated specs.

glassdoctor · 11.15.2006, 10:47 AM

If anyone has noticed glitch #2.... post what setup you have... more info the better.

I gotta think the on road guys would notice this...

glassdoctor · 11.15.2006, 11:04 AM

I agree it's the same basic flaw in all the glitches... esc firing the wrong coil... backfire of sorts, but there is a big difference between #1,3 and #2.

#1,3 happen when the car/motor is stopped, or at least when it's changing direction. This is a rather common issue with sensorless systems, an inherent flaw.

#2 happens while the car and motor are moving... not just barely moving either.

It is "supposed" to be impossible for this to happen. In fact the first thing the guys at CC said was basicly "impossible... that can't happen....".

But it does happen and we (they) need to find out why.

BrianG · 11.15.2006, 11:13 AM

While #1 and #3 are common sensorless symptoms, I have NEVER seen that happen with my Quark 125.

Is maybe #2 because of the relatively large motor you have on there? I know it technically works, but the MM was never designed to be used for 1/8 scale apps with large motors. It would be nice if CC could fix this though as the MM can obviously handle the load for the most part.

Here's a thought; does #2 have anything to do with the use of a 4 pole motor? Maybe try a regualr 2 pole, like a Wanderer as a test. After all, it's only $90. A 7XL or 8XL should approximate the Neu you are running pretty well. Of course there will be differences, but it's just a test.

glassdoctor · 11:26 AM

#2 glitching is with a stock Mamba Max system... in a 1/10 buggy. We are running htem exactly as they were meant to be used, and everything is great except for this occasional hiccup.

The other cogging issues are with the 1/8 stuff and big motors etc and I can't fault the MM for that... although I'm expecting CC to cure this with software updates.

cart213 · 11.16.2006, 11:34 PM

I've got #3 with my system, which I've mentioned before in other threads. To recap, I've got a 1/8 truggy with the MM esc and a Neu 1512/2.5D motor running on 4s (or 6s) li-ions. The radio is a Spektrum DX3. I'm glad that I'm not the only one with the problem. At first I thought I got a bum esc. Hopefully, CC will come up with a software update to fix all these problems.

BP-Revo · 11.17.2006, 01:13 AM

I'm no sensorless expert (I actually have an HV in my G2R...so I dont worry about any motor issues of the sort), but I read the thread and thought it was rather interesting.

Is it something you can do on purpose if you tried? Would pumping the throttle eleminate it?

I run on a very tight track (meant for 1/10 buggies and ST's) and when I used to have my E-Maxx with stock motors (lol...those were the days) whenever I had any issue with cogging a quick pump of the throttle would solve it. Same goes with braking. It doesn't even have to be a total return to neutral, just simply reduce whatever imput you are giving for a fraction of a second.

Just a thought...

I am also kind of concerned because I am thinking on getting the MMM when it comes out (probably with the slipperential), and I figured it will have similar programming to the MM. I am racing with it and at the speeds I drive my truck I can't afford any glitching. I take corners at the point that I rely on the weight transfer to keep enough traction to keep me from spinning out. I have taken corners so fast I've ejected batteries from my G2R chassis...lol

glassdoctor · 01:36 AM

I have faith they will fix #3... and I would think the MMM will not have problems since it will be designed and tested with the big motors. Just like the MM doesn't cog in 1/10 cars with the MM motors. (except for Brian's #2 reverse-to-forward thing) :)

I race hard and can't afford any glitching either, which is why I've been working on CC to look into it. Last night I stuck it in a pipe on the last lap of qual and slipped 3 spots in the main with that bobble... There are a few locals that kick my butt here that are close to top factory driver skills...

Small update: I raced last night and had less trouble than last time. I had reset the radio end points for the brake back to maximum (160% on the M8) and used the MM software to dial out the brake instead. It ended up on 20% on the MM and 150% on the radio. And the drag brake was at 30-35%

This seemed to do a lot better, although I had one definitely glitch entering a sweeper. It was a little different than what I was getting before. But it was the ony one like it out of about 6 packs I ran. Good news there...

The thing I didn't like last night was that the power or powerband feels a little inconsistent from lap to lap, corner to corner.... one minute it's a missle and then out of the next corner it seems to lack the same snap. Not a big difference, just something sublte.... but you can tell it's not the same every time you get on it. I have an old Novak Cyclone that is like that, only much worse...

I have no idea what to think about this. I don't recall this at all when I first got it. Last night there was a ton of traction and I had the slipper a little tight, so it could pull the front off the ground coming off the corners. This was mainly where the inconsistency showed... if I had the slipper loosened up I'm sure it would be much less noticable.

I don't know if I'm familiar with it now so I notice little things the more I run it or what... I want to swap it out for a differnet esc and see if it feels the same.