Mamba Monster has delay with throttle input
 

I installed my backup Mamba Monster that I had purchased a while back, but never used until yesterday. I'm am running it on 2s with a B50-5S Hacker motor. kV is about 7400. Batteries are 2s GensAce 5000mah. Gearing 46/13 in the RCM CRT.5 with 3" tires.

Problem is that when I give it throttle there are a few seconds delay for the ESC to ramp up to full speed. I have reflashed the ESC to the latest firmware, just in case and same results. I've even tried the default settings with the same results. I've swapped RX's and same thing. Rebound the ESC to the RX a bunch of times and nothing. My Radio settings are stock as well.

Suggestions anyone? Just send the ESC back?

The latest/later firmware is the problem- you need to downgrade it to an earlier version ( v1.24 is the last known 100% stable and reliable firmware ).

coolbeans. I'll try it today.

It's a no go. ESC is no good. Verified against MMpro. Bummer that I can't run that B50 yet.

Hmm, have you tried the MMM with a different motor, checked for any cold solder joints on any of the connectors?

I've tried 4 motors and checked out everything. The connectors with the motor wires came off the RSpro, which worked fine. I'll try again today on higher voltage and see what's up.

The MMpro limits my gearing options on 2s, whereas the MMM doesn't. The RX8 is powerful and smooth, but the MMM is still king on high amp 2s setups without breaking a sweat.

I had the same problem wit a new MMM ESC.
I had to send back for the replacement.

Good to know.

Just bought a new Flux XS for my son last night, went to power it up, same deal, hesitates on initial accelleration, battery is a Turnigy Nanotech Hardcase Lipo 65c/130c 6000mah..... and you people wonder why I am castle critical???

Hi Snell,

Well, the issue is this:

The controller gives throttle to the motor, the battery voltage drops quickly below 5.8V (cutoff...)
The controller sees the battery voltage drop, and throttles down to protect the battery.
The battery voltage rises again, so the controller throttles up
The battery voltage then drops again,
and so on...

until the speed rises enough that the controller can give throttle without the battery voltage dropping significantly.

Usually caused by:

Insufficient battery
and
mismatched pinion

We see this a LOT -- and the issue is easy enough to fix.

Thanx!

Patrick

Hey Patrick,

I tried several 2s packs and some behaved better with the V-cutoff disabled. Tried a 4s pack and it got better. Basically you are right about me having sucky 2s batteries for what I'm trying to achieve. I'll get a better 2s pack and try again.

Thanks for the reply.

Snell,

You can try dialing in some punch control, or some torque control. Both will limit the current into the motor at startup and may relieve the problem somewhat.

I'd suggest trying a torque limit of 1.5 or so.

Thanx!

Patrick

Patrick,

I tried the 1.5 torque limit setting and it just was sloooowww. I then went ahead and set the punch on 20% and all was well with the 1506 Neu motor w/19T pinion. Speed was in the 60's mph.
I then swapped in the B50 5s 7400kv Hacker motor with a 20T and did a single run with the truck dead. I blew the copper traces off my lipo. I soldered on some copper braid wires and the monster within came out. I'll reduce the punch to 30% and call it a day. Speed was nearing 70 mph. Mike RCM CRT.5 chassis stayed planted to the ground.

Thanks for the support Patrick!


http://i189.photobucket.com/albums/z...5/DSC08493.jpg



http://i189.photobucket.com/albums/z...t/DSC08491.jpg
http://i189.photobucket.com/albums/z...t/DSC08488.jpg

Hey Snell:

Instead of doing the punch control, try dialing up the torque control.

The main difference is torque control controls current at the motor, and punch control controls the throttle change rate.


Just keep pushing up the torque control until it feels good. I think it works significantly better than punch control -- and it will help the components survive better.

Thanx!

Patrick

Achieving those speeds in a 5+lb 4wd truck on 2s is impressive. I wouldn't want to be your lipos though, thats putting some serious draw on them

Impressive it is. What is more impressive, is that Patrick himself is giving me advice on how to make it work on my cheap lipo's. Time to get a Hyperion 45C 5000mah pack, if I can find one in stock.

The C40-5L Hacker and Neu 1506 6800kv motors are easier on the batteries, compared to the B50S Hacker. Timing on the Hackers is set for 5 degrees and the Neu at 10 degrees. The current GenAce battery pack is only good up to 60% capacity. After that the CRT.5 is just slow.

I went ahead and played around with the torque settings. I ended up with 9, which gives me good results. I'll drop the pinion a bit and see if I can bash with this motor.

In a way, it's kinda neat how the PCB trace in the lipo blew. Sort of like a protection fuse. I know you defeated it (similar to replacing an old-style house fuse with a penny), but less knowledgeable people probably wouldn't chance it, which is probably good to help protect them from being stupid.

I agree Brian.

Hey, one more thing...

ADD some capacitance to the battery side of the ESC. You are probably really stressing the capacitors. If they fail, the controller will go BOOM. :yes:

Tonite I finally had a bit of time to myself to work on the ESC. I added three 35V 1000uF Rubycon caps to the ESC and like magic my issues went away. ESC is very responsive now and brakes are better.

http://i189.photobucket.com/albums/z...5/DSC08559.jpg

Ran it a bit today during my break. I still get only 2100mah use out of my pack before the ESC slows me down. Batteries were barely warm. ESC and motor were below 180F. Gearing was 46/18 and speeds seem to be in the mid 60's. The extra caps were nice and warm. I'll change the deans out for EC5 and start to datalog this setup.

Here's the vid of the torque control activated. Smooth startups. Even using the same batteries that I had to add some copper too.

[YOUTUBE]4uZKCUJplus[/YOUTUBE]

What firmware version are you using?

is this true?

I'm using the latest firmware on both of mine.

That's where is your prob!
Go back to 1.24

No problems anymore. Problem fixed with additional capacitors and torque control(current limiter).

someone please confirm this is THE LATEST CASTLE FIRMWARE FOR THE MONSTER GLICH FREE OR NOT?whoever brought this up, castle helllllp!

The latest Castle firmware works just fine. The stutter problem snellemin was referring to was caused by the pack voltage dropping so low on startup that the processor on the ESC was resetting. As he said, adding additional capacitance to the input and using some torque control solved the voltage sag problem.

Thanx!

Patrick

thanks for clearing that up sir.