I'm sick of my Mamba!

[freemachinist]

Hi guys,
I have a Mamba 5400. I thought I loved it, especially when my lithium battery was working. With just a regular 6 cell pack this this just hesitates more than it moves. The "cogging" that every body speaks of, SUCKS! If I have a fresly juiced battery, it does OK. As soon as the voltage drops the hesitation begins. AND, to add insult to injury, reverse is DISABLED (locked out) yet my truck still goes in reverse. The poeple at Castle Creation want my whole set up to be sent in. HA, I need my radio for my other vehicles.
Anyone else having problems?

[Rtsbasic]

What batteries are you using? GP1100's shouldn't cog at all until the pack dumps. I used 6 cell GP's on my mamba 8000 with absolutely no cogging issues.

If your controllers one of the older versions if you send it in they will attach a bigger power cap to it and maybe update the programming to minimize the cogging.

[freemachinist]

What batteries are you using? GP1100's shouldn't cog at all until the pack dumps. I used 6 cell GP's on my mamba 8000 with absolutely no cogging issues.

If your controllers one of the older versions if you send it in they will attach a bigger power cap to it and maybe update the programming to minimize the cogging.
I'm using the stock batteries that came with the RC18T. They are not GP's. I've had the cogging issues even with a Reedy Mini Max battery and my now dead lithium battery. There hasn't been a battery in my truck that didn't cog, even with a fresh charge. I'm really tired of this. I've been in touch with CC, but they have not told me to send in the ESC.

[tcolesen]

Those stock batteries are "cheap" and can't handle the loads put on them. It is very similar to what happens with a 1/10 car and using cheap $8 packs instead of GP3300s.
You say your lithium polymer battery is dead. Have you discharged it below 3v/cell? It shouldn't just be "dead", because if it is, then there is a problem. BTW, what brand is it?

[ducati777]

I know what you mean, I tried the stock pack on the 5400 and it really didn't work. I'm a firm believer that brushless systems need high voltages. Get yourself a 3 cell lipo and you'll be singing the mamba's praise. Polyquest 1800 3s packs are a perfect fit, talk to Jamie for a good deal.

[Baja-Destroyer]

i use the smc mini t pack for my mini t works perfect with my mamba 6800 and i know there not the super best of cells

[TheSteve]

I know several people that use the stock 18t pack with the mamba with very little cogging - its certainly not as powerful as a GP1100 pack of some good LiPos but it should work. If you have the datacable you can try flashing your mamba with newer software. Also try the other settings(startup/timing) Also make sure your connectors and all solder connections are in good shape - they can all make a difference.
One last thing - whats your gearing? You can try a smaller pinion(or upgrade to the 60 tooth spur - it should have been included out of the box)

[freemachinist]

Guys,
All good advice! But I've tried it all. My ESC killed my Lipo. I left the lipo plugged in and the voltage cut off did not work correctly and fried my lipo, it was a thunder power. All my connectors are in great shape. I am running a 10/60 set up. I know its the ESC because all these problems go away when the stock set up goes back in the truck.
I have finally been told by CC to send it in for testing. So i'm going to do so. Thanks for all the help! :)

[kufman]

Do you still have the voltage cutoff set for the lipo? Try putting the cutoff on the lowest voltage setting. I run the mamba 5400 in my 18t with the stock battery and have absolutely no cogging at all. Use oftion #1 for the voltage cutoff, 0V. Reverse lockout, option #1, does not disable reverse. Option 2, Proportional Brake, no Reverse, does disable reverse. The mamba's voltage protection does feel like cogging. So if you get another lipo and it starts cogging, it is probably discharged!

[ducati777]

You know I'm sitting here thinking... Usually torque in an electric motor has a positive relationship with amps. More amps, more torque. Cogging happens from a standstill, until the motor makes enough rpm to generate back EMF, the ESC doesn't really know which coil to hit.

The 5400 is like a higher turn motor, and draws less amps. In my setup it was clear that the stock pack couldn't produce the volts needed to draw the amps. It cogged badly after 5 minutes or so of solid running. The lipo solved that problem as it runs 11.1 volts and all the amps I need. I've even considered a 4 cell pack just for giggles.

Long story short, I think the 5400 will cog much worse than say the 6800 or 8000 on a stock pack. The lower turns of the 6800 & 8000 will force the amps up due to lower resistance. Anyone agree?

[4W Guy]

Guys,
All good advice! But I've tried it all. My ESC killed my Lipo. I left the lipo plugged in and the voltage cut off did not work correctly and fried my lipo, it was a thunder power. All my connectors are in great shape. I am running a 10/60 set up. I know its the ESC because all these problems go away when the stock set up goes back in the truck.
I have finally been told by CC to send it in for testing. So i'm going to do so. Thanks for all the help! :)

I have the 6800 motor. Using 12/60 and the stock battery, I have had no cogging. About your battery goung dead. I left the battery hooked up with the switch turned off for 4-5 hours during the rebular races one day. When I came back to run some more, the battery was completely dead. Had to charge in order to run at all.

[TheSteve]

Anytime you're using a LiPo you must unplug it when done, just because you turn the power switch to the off position does not mean it will not slowly drain the battery.(this doesn't just apply to the Mamba)

freemachinist - how long have had the Mamba, its possible you have one of the original releases which cog a lot more then the current model, they did make a hardware change early on.

[kufman]

Long story short, I think the 5400 will cog much worse than say the 6800 or 8000 on a stock pack. The lower turns of the 6800 & 8000 will force the amps up due to lower resistance. Anyone agree?

I would have to say that this is backwards. The drawing of amps is what lowers the pack voltage and causes problems for the speed control. Your cogging started at 5 min because the pack voltage had fallen and you were drawing lots of amps which bring the voltage down even farther. Below a certain level the battery can no longer support the BEC function and the speed control has to phase back because it no longer has enough power to operate or to give to the receiver. This tends to go away with higher voltage packs because the critical voltage for the receiver stays the same, 5v. If you are starting at 11.1V, you battery cutoff is far above 5v. When you start at 7.2 volts and you draw lots of current, it is easy to draw the pack down to less than 5V. This I wouuld not call this cogging, this is more like power limiting to prevent power loss to the radio. sometimes a larger power cap can help and also a cap on the receiver can help too (this is a great fix for lehner speed controls). Novak called this radio priority circuitry in their earlier models of brushed esc's. Novak has a nicer way of doing it where the motor power is decreased but not completely cut off.