Fireteam Fast & Furious Fireteam (need help)

[obessedwithrc]

So I bought the Fireteam on a whim during the $399 deal. Then I got bored over the break and decided to strip it down and rebuild it from the ground up. Name all the basher upgrades from M2C, Basherqueen, Vitavon, RPM, stainless steel screws, etc., and I'm probably running it, but I'm having problems with power loss. I'm getting intermittent power loss at full speed on a 17t pinion like it's surging. I think it could be a few things...

1. The battery wires are too long
2. I need a bigger ESC
3. I'm getting voltage sag from the battery
4. The wires aren't large enough in diameter (10 gauge) to transfer the power
5. I need to install a capacitor as they use for speed runs
6. My soldering job sucks

Any thoughts?

I am using 5450 mah 6s 120c battery from Max Amps, Castle Connectors, and the MMX 8s. See motor details in the pics:

Here's the motor that I'm using. It's a BEAST. Dimensions: 36 x 101mm with an 8mm shaft @ 2000kv

Top view:

Side view:

 

[Fishtank]

First that is one Fireteam! Nicely done! I’m thinking 3 or 5 because if it was 6 you’d probably have a meltdown by now.

 

[slick2500]

If I had to guess you are either over geared and or the motor is pulling more amps than the battery can provide. IIRC those motors can pull a boat of amps.

As a side note every lipo seller over rates their C rates some more than others. https://www.arrmaforum.com/threads/c-rates-what-is-the-deal.17174/

If your charger has an IR meter check the IR of the cells.

I would gear down to like a 14-15T pinion and see if the problem persists.

 

[obessedwithrc]

Thanks, @slick2500. You hit the nail on the head. The Max Amps battery wasn't up to the job. I switched over to a 6300 mah SMC battery 135c and there's no power loss. That was the trick. I'm super surprised because Max Amps is supposed to be one of the better brands out there—especially with their premium prices.

I'm still wondering if I should put an extra capacitor on there just to protect the ESC. I wonder if that's necessary given that the power loss is gone. I know the MMX 8s can log data, but I wouldn't know how to read it. I'd have to do some YouTubing on that subject.

 

[Mikeeeeeal]

Dope rig there.

 

[@9G]

I'd get rid of the MaxAmps. They're a little overrated IMHO. I have one and haven't have a good experience with it. They have an excellent return policy and a limited lifetime warranty but I've had to send it back to them once already for a bad cell. The performance is OK but there are better batteries that don't cost as much.

Another thing you can try is putting a cap pack on your receiver. You might be getting power loss or high current spikes to the receiver. They're pretty cheap and help smooth this out. I was having the same issue with one of my MMX8S and the receiver cap pack helped a lot. I'd try QS8 connectors too. That Cordova is a beast and needs a ton of current. QS8 is the best for handling all the current load required by the motor.

Excellent build also...That thing is a masterpiece!

 

[obessedwithrc]

Dope rig there.

Thanks, @Mikeeal !
Thanks for the tips, @9G! I think I'll add a cap pack.

I'd get rid of the MaxAmps. They're a little overrated IMHO. I have one and haven't have a good experience with it. They have an excellent return policy and a limited lifetime warranty but I've had to send it back to them once already for a bad cell. The performance is OK but there are better batteries that don't cost as much.

Another thing you can try is putting a cap pack on your receiver. You might be getting power loss or high current spikes to the receiver. They're pretty cheap and help smooth this out. I was having the same issue with one of my MMX8S and the receiver cap pack helped a lot. I'd try QS8 connectors too. That Cordova is a beast and needs a ton of current. QS8 is the best for handling all the current load required by the motor.

Excellent build also...That thing is a masterpiece!

First that is one Fireteam! Nicely done! I’m thinking 3 or 5 because if it was 6 you’d probably have a meltdown by now.

Thanks, @Fishtank !

 

[SrC]

If I had to guess you are either over geared and or the motor is pulling more amps than the battery can provide. IIRC those motors can pull a boat of amps.

As a side note every lipo seller over rates their C rates some more than others. https://www.arrmaforum.com/threads/c-rates-what-is-the-deal.17174/

If your charger has an IR meter check the IR of the cells.

I would gear down to like a 14-15T pinion and see if the problem persists.

+!
We think a like.
That motor and gearing is wrong for this heavy off road rig. Added even more weight with all the upgrades as it is.
Why aren't you refering to the CC data logs. You aren't looking closely enough. You slammed your rig with Much $$. Nice at that. Maybe overkill at the expense of performance??? Just need to focus more on the ESC Logs to evaluate best. Your electrics might be better suited in a Lim or Infraction. In a FT Not too sure. 2000KV Cordova, probably not the best choice. Not enough torque. Just maxing out the RPM's if anything? I would drop the pinion down first and see if there is any change. But def need to Get into the CC Data logs. It will show you where you went wrong. Take advantage of the MMX8s data logs. Show us the logs here. I hope you are Using a temp gun to evaluate that 2000kv motor, lipo and ESC temps. Otherwise you are Blind running this rig. Use a speed gear calculator for reference.
Good luck.
Don't expect your FT to do 100mph with those FT tires. Whether in dirt/grass or on Pavement. Not happening,

 

[slick2500]

Thanks, @slick2500. You hit the nail on the head. The Max Amps battery wasn't up to the job. I switched over to a 6300 mah SMC battery 135c and there's no power loss. That was the trick. I'm super surprised because Max Amps is supposed to be one of the better brands out there—especially with their premium prices.

I'm still wondering if I should put an extra capacitor on there just to protect the ESC. I wonder if that's necessary given that the power loss is gone. I know the MMX 8s can log data, but I wouldn't know how to read it. I'd have to do some YouTubing on that subject.

On paper Maxamps is supposed to be but real world testing shows them to be some of the worst performers. They tested that particular battery on Rcgroups and it had a real C rate of 10c and that was before he changed his testing to the max sustainable c rate not the max achievable.