mamba max pro problem - RC-Monster Forums

**mamba max pro problem -** 10.31.2009, 02:02 AM

ok heres the thing , i have noticed when using my mmp on a hightec 5955tg or 7955tg when you turn the wheel alot it will glitch and some times the motor will turn on and the servo just stops , ive tryed to run it on 5.5v-7.v and still the same thing , also had a guy runnin one here at the track also and it did the same thing , one more thing my fan allready stoped working i was runnin it on a 6.5 and noticed it seemed like some thing was wrong , i pulled it off the track and temped the ESC and it was at 210 never did get the fan to work , is it posable to send in just the fan ? thx joe

What's_nitro? · 02:05 AM

Are you running a 2.4GHz radio? It could be interference from the metal gears if you aren't. Otherwise there may be binding in the steering mechanism causing a BEC overload...though that doesn't really explain the motor movement.

10.31.2009, 03:02 AM

yep running 2.4 even did it with just the servo layin there not in the car , just with the arm moving left to right , idk what i could be ive seen it on 2 production mmp now , the beta model i have does not do it

What's_nitro? · 10.31.2009, 01:06 PM

I wonder what's changed between the beta and the production model?

Pdelcast · 10.31.2009, 02:09 PM

Quote:

Originally Posted by What's_nitro?

I wonder what's changed between the beta and the production model?

Nothing changed between the Beta and production models...

Joey, have you tried swapping out the RX?

10.31.2009, 02:45 PM

yea it has happend to both of my rx's and my buddy that i race with i will try and make a video and up load it

10.31.2009, 03:15 PM

[YOUTUBE]<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/iARm5lq5ESI&hl=en&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/iARm5lq5ESI&hl=en&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>[/YOUTUBE]

sikeston34m · 10.31.2009, 05:11 PM

Quote:

Originally Posted by fatkidjoey

[YOUTUBE]<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/iARm5lq5ESI&hl=en&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/iARm5lq5ESI&hl=en&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>[/YOUTUBE]

This looks like the same behavior I've been seeing with the MM Pro.

My setup uses a Pair of MG995 Servos. I blamed it on a bad servo even though I had just installed them both brand new. I then brought it in the house and swapped out the servos.

I haven't had a chance to run it again yet though. Hmmm..........

How many amps is the MM Pro BEC supposed to be good for?

BrianG · 10.31.2009, 05:39 PM

Quote:

Originally Posted by sikeston34m

How many amps is the MM Pro BEC supposed to be good for?

I just did a quick test with various loads with the BEC set for 6v:

5.94v unloaded
5.76v @ 0.48A
5.72v @ 0.64A
5.70v @ 0.95A
5.63v @ 1.87A
4.16v @ 2.77A

Not sure exactly what point the BEC voltage hits its max, but I would say right around 2A. As you can see, the output falls dramatically somewhere around there.

sikeston34m · 05:54 PM

Quote:

Originally Posted by BrianG

I just did a quick test with various loads with the BEC set for 6v:

5.94v unloaded
5.76v @ 0.48A
5.72v @ 0.64A
5.70v @ 0.95A
5.63v @ 1.87A
4.16v @ 2.77A

Not sure exactly what point the BEC voltage hits its max, but I would say right around 2A. As you can see, the output falls dramatically somewhere around there.

Thanks Brian,

This explains what I witnessed.

A High Torque Servo is likely to draw more amperage than this, especially when fed more than 5 volts. And especially a Pair of High Torque Servos.

Hmmm....... I thought the Internal BEC would be more beefy than this.

Is this a firmware issue? I was running version 1.2, since I read there were motor starting issues with version 1.3.

10.31.2009, 05:50 PM

nope i dont think so i ran 1.24 and still did it , i went back to .22

sikeston34m · 07:06 PM

Quote:

Originally Posted by BrianG

I just did a quick test with various loads with the BEC set for 6v:

5.94v unloaded
5.76v @ 0.48A
5.72v @ 0.64A
5.70v @ 0.95A
5.63v @ 1.87A
4.16v @ 2.77A

Not sure exactly what point the BEC voltage hits its max, but I would say right around 2A. As you can see, the output falls dramatically somewhere around there.

There are several other factors of actual running that will affect these results.

If your tests were quick, the ESC was not up to operating temperature. With the ESC powering a drive motor and carrying an amp load, the BEC circuit temperature will rise just from the heat being given off by the Power board.

What are the results on 6S input voltage?

After signing up to be a Beta Tester for these units, I'm sure several thousand people signed up before me.

In Actual running, it was noticeable, the glitching really didn't set in until after 10 minutes or so. This leads me to believe, temperature affects BEC output.

The "Glitch" would show itself in the form of:

If I were turning, the steering would momentarily stay in that position or the truck would not turn when going straight.

Afterwards, I disconnected the steering and checked for binding. There wasn't any binding.

suicideneil · 11.01.2009, 08:25 AM

Interesting...

I have seen on my many travels that for high powered servos, esc manufacturers recommend running an rx pack (of sorts) wired to the servo in series ( I think) via a y-splitter, so that the esc was only really providing the signal to operate the esc, with the rx pack providing the go-juice; rather like having a glitch-buster capacitor plugged into the rx.

Not the most compact or elegant solution, but one of three options along with the cap or running an external BEC..

BrianG · 10.31.2009, 03:34 PM

The receiver light going out is a clear indication of no/low voltage from the BEC. However, what is causing that? It could be a faulty/weak BEC or maybe there is something wrong with the servo itself.

To eliminate the BEC as the culprit, try a receiver pack or external BEC. If it still has issues, I would suspect the servo.

I had a Hitec servo a while back where one of the internal gear pins had worn away the exle point in the case and elongated the hole. It would run fine sometimes, but then other times would bind up and stall the motor and do exactly as you describe, even with no load like you demonstrated.. Do you have any other servo you could try?

Semi Pro · 10.31.2009, 04:04 PM

i have had the problem before, turned out to be the servo, i would try it with another servo, if it still does it then you have a bad bec