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Old 08-24-2007, 04:59 PM   #1
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Default Mamba max lipo cut-off

I had my mamba max set to auto cut-off, but now i have it set at 6v, im using an orion carbon lipo.

Now, when it gets close to cut-off, i would say anywhere in between 6.5 - 7 volts, it stutters (cut out then comes back on again), and i dont think its thermal. I've checked the motor temp, its hot but i have had it hotter, and yes im investing in a 40m fan. So somehow i think it has to do with either the cut-off, or the lipo itself.

the lipo might need a balance, ill check both cells out with a voltmeter, and im also going to see what it does with no cut-off. But has anyone experienced the same if not similar to what i've just described??
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Old 08-24-2007, 06:18 PM   #2
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YES! I've had the exact same happen to me. I have a nearly brand new (about 30 minutes of run) on my MM6900. I am running a 6000 7.4v Maxamps and mine was doing the same. It would act like its almost like the radio is cutting out and its not getting good signal but Im not sure if it was near its cutoff or what. I felt the motor and it was so so with the heat but I checked the ESC cooling fins and it nearly burned my finger it was so hot. Im definatly getting myself a fan to mount on that thing.

Just wondering... what sort of fan are you looking into?
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Old 08-24-2007, 06:40 PM   #3
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How are you getting the 6.5 - 7 volts measurement? If you check with a multimeter after the problem occurs to get that number, it's possible the voltage is dipping below cutoff under load.
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Old 08-24-2007, 06:40 PM   #4
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Default Known Mamba issues..........

You will have much better performance from your Mamba systems if you ditch the gold connectors and solder the motor wires. Trust me, it works.
I have 2 Mamba systems and they both exhibited this same problem.
Also, Mamba's like really good batteries so make sure you have quality LiPos.
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Old 08-24-2007, 06:43 PM   #5
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You will have much better performance from your Mamba systems if you ditch the gold connectors and solder the motor wires. Trust me, it works.
I have 2 Mamba systems and they both exhibited this same problem.
Also, Mamba's like really good batteries so make sure you have quality LiPos.
Alright so direct solder the leads to the motor? Is there a certain length the wires need to be? I heard it makes a difference on mambas.

Would you consider a Maxamps lipo quality?
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Old 08-24-2007, 07:25 PM   #6
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I have hardwired the motor & you can just see the orion lipo in the background. I was using those 2 fans you see there, but found they took alot of runtime, so now im just opting for the 1 40m 5v fan and connecting it via the rx.

kuzo - you might be right there mate. It sorta sounds like that, but i really need to check with a multimeter. But if that is the case, & the cells need to be balance, do you think it will solve the problem?

If thats the case, the voltage is dipping below cut-off under load, im sticking to the 6v cut-off rather than no cut-off. It tended to do this alot with the auto cut-off aswell, alot more compared to the 6v cut-off...

I have actually noticed when the batt is low, & i half throttle it from a stand still, i can hear the motor start off low, then get its correct revs, if you understand what i mean!
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Old 08-24-2007, 07:42 PM   #7
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Quote:
Originally Posted by Drift Demon View Post


I have hardwired the motor & you can just see the orion lipo in the background. I was using those 2 fans you see there, but found they took alot of runtime, so now im just opting for the 1 40m 5v fan and connecting it via the rx.

kuzo - you might be right there mate. It sorta sounds like that, but i really need to check with a multimeter. But if that is the case, & the cells need to be balance, do you think it will solve the problem?

If thats the case, the voltage is dipping below cut-off under load, im sticking to the 6v cut-off rather than no cut-off. It tended to do this alot with the auto cut-off aswell, alot more compared to the 6v cut-off...

I have actually noticed when the batt is low, & i half throttle it from a stand still, i can hear the motor start off low, then get its correct revs, if you understand what i mean!
Absolutely stick with the cutoff. When you get down to the lower voltages, you are more likely to get below cutoff under high draws. When you let go of the throttle and check the voltage will be higher. Which motor are you using?
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Old 08-24-2007, 08:02 PM   #8
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Being I only run a 2s lipo should I have it set at 6.0v(think thats the 2s cut off) or autolipo?
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Old 08-24-2007, 08:15 PM   #9
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Quote:
Originally Posted by platinumjason View Post
Being I only run a 2s lipo should I have it set at 6.0v(think thats the 2s cut off) or autolipo?
I don't run the mamba but I assume the autolipo means it detects the pack configuration? If so, and you can set manually I would do so to no less than 6V. I'll take a look at the manual online as I know the mamba is pretty customizable. I would personally set 6.25V cutoff like the Novak Smart Stop if it's capable.
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Old 08-25-2007, 07:59 AM   #10
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I went back and looked through my mamba instruction book and they said not to shorten the wires at all. They said if you dont like the connectors on the wires to desolder the connectors and direct solder from that to the esc. They said shortening the leads will make it no run right.
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Old 08-25-2007, 02:03 PM   #11
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Default Straight from Castle tech support...

Quote:
Originally Posted by platinumjason View Post
I went back and looked through my mamba instruction book and they said not to shorten the wires at all. They said if you dont like the connectors on the wires to desolder the connectors and direct solder from that to the esc. They said shortening the leads will make it no run right.
Per Castle tech support, it is very safe to shorten the wires on on Mamba motor. The cauthion is really more for other BL motors where you might cut into the sensitive parts of the motor wire.
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Old 08-25-2007, 05:01 PM   #12
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kuzo - i have a 4600 atm, and ill probably stick with it.

Im thinking about grabbing another lipo, and i was thinking about geting another orion/peak carbon. I have also been thinking about grabbing a maxamps 5000HV lipo. Which one do you think would be more suited to the mamba max. although they both have 20C continous discharge rates, the maxamp has more amps in its discharge rate compared to the orion/peak carbon.

Im thinking when my orion carbon gets near low, the mamba just wants to draw more amps where the orion cant handle it, but do you think this is the case to why it justs cuts out before cut-off?
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Old 08-25-2007, 05:12 PM   #13
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Well, if you were drawing more amps than the battery could handle, you'd end up with more problems than just the cutoff. How long into running the pack are you getting this problem?

On the Maxamps vs. Orion question - I am done recommending Maxamps for any purpose. I don't want to ruin your thread with that topic so if you want to know why, PM me or read some of the other lipo threads running right now.
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Old 08-26-2007, 02:46 AM   #14
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Quote:
Originally Posted by Drift Demon View Post


I have hardwired the motor & you can just see the orion lipo in the background. I was using those 2 fans you see there, but found they took alot of runtime, so now im just opting for the 1 40m 5v fan and connecting it via the rx.

kuzo - you might be right there mate. It sorta sounds like that, but i really need to check with a multimeter. But if that is the case, & the cells need to be balance, do you think it will solve the problem?

If thats the case, the voltage is dipping below cut-off under load, im sticking to the 6v cut-off rather than no cut-off. It tended to do this alot with the auto cut-off aswell, alot more compared to the 6v cut-off...

I have actually noticed when the batt is low, & i half throttle it from a stand still, i can hear the motor start off low, then get its correct revs, if you understand what i mean!

i got mine set a 6.3v and im running a 6200mah lipo so usually i never get down that low, adn auto lipo just sets the cut off at 6.3v and why are you running fans if you gearing is right you shouldnt need fans
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Old 08-26-2007, 03:15 AM   #15
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i had fans because even with the highest ratio possible (TT01 - 61/19 = 8.35 FDR) after a 30min run the motor is really hot, ive actually been considering a TCS for quite some time now. I took the fans off because i found they drop the runtime alot, i might hook them up again, but instead of using 2 x 25mm fans, i was going to opt for 1 x 40mm fan...

I have a 67T spur from a DF02, but in order for it to fit i have to make a few mods to the gear cover & bottom of the chassis... but a 67T spur & 19T pinion will bring it to around the 9 mark...
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