Cheaper Alternative ESC for MM/8xl E-maxx??

HI everyone. I currently run a MM ESC in my Emaxx with an 8xl feigao motor. I Have been running 14 cells with MM bec disable and use a receiver pack.

The MM ESC heats up way too much for my liking! Even with a fan, it occasionally thermals.

I am looking to purchase a better suited ESC for handling 3s Lipo packs that is similar and/or better than the MM, that is better suited for an E-maxx, but is still at a budget price range.

I was thinking maybe between these models:

BK Electronics 12020 Warrior Car Controller $224 CAD
MGM Compro 80 amp, 12 cell brushless car controller $178 CAD
Warrior 9920 Brushless Car Controller $143 CAD
Quark 65 amp Roadster Car controller - Sale Price! $143 CAD

Basically, I just want something that won't heat up too badly, suited for Emaxx, and can handle 3s-4s Lipos.

Can you recommend any of these ESC's or have any other suggestions/input?

Thanks!!

[What's_nitro?]

Wow, I bet the motor gets hot, too. You should look for an ESC with a higher current rating than the MM. If you are upgrading to LiPo's, this is imperative. The motor will pull a lot more current because the LiPo's voltage wont drop under load nearly as much as NiMH's does. A rating less than, or equal to, the MM's 100A won't see much, if any, improvement as far as temp's go. Out of that list I think the BK 12020 would be your only option, considering you want 4s LiPo capability with the 8XL. IMO an MGM 16018, while more expensive at $275, would be a SOLID controller for your truck.

I would love to get the MGM compro 160, but $300 CAD seems a bit of my price range now, but if thats what I really need to get the results I desire then I guess I'll just have to wait a bit and save some more.

DO you think the BK Warrior 12020 will heat up just as much as a MM?? on 3s

[crazyjr]

I to think the 16018 would be the best for you, even if its a little out of range. It will give you some room to step up and still keep cool

Ok, thanks guys for your help again!

[bdebde]

If you are running an 8Xl on 3s (or equivalent) then it is no wonder your ESC is getting too hot. You really need more voltage with the 8XL.

Yeah I kinda figured that from the start. I knew the MM was not meant for use in 1/10 monster trucks. Its just that I've read that a few people on this forum and traxxas forum run similar setups in their Emaxx's and Revos. A MM with either a 7xl, 8xl, or 9xl. With 12-14 cells, or 3s lipos.

[jhautz]

The BK12020 would do well for you in your application with 14 cells and an 8xl on an emaxx. I run one in my Savage on 5s2p A123 and a Lehner 1940/7 (2239kv). It runs fairly cool, without ever thermaling. Only downside with it is you need an external lipo cutoff if you intend to go to Lipo in the future. Not the end of the world, ($30 item) but its just another something to attach to the truck and make sure its hooked up right.

While the BK12020 will work, I agree with everyone else that the MGM16018 would be an ideal controller. It has all of the nice features of the MM (and a few more IMO) with more power handleing than you will ever need. If you are willing to spend 224 for the BK, save up the extra 76 you will need to get the MGM. Its worth it in the long run. The BK has no adjustability, no lipo cut off, no computer programing, etc. and the MGM has the bonus of nott needing an extranl Rx pack or UBEC. It has a switching BEC built in.


One question.... Why are you planning to run 3s? The emaxx and the 8xl would be much better suited to 4s. 3s will just create more heat (due to higher amp draw required to creat the same power on lower voltage) and would probably feel under powered compared to the 14 cells that you run now. When you decide to go lipo I would recomend looking into 2-2s packs run in series for a 4s (14.8v) setup raather than the 3s you mentioned.

Before you do any of this look into a few things to try and optimize you setup first. With a few adjustments you just might get it running acceptably for you. Or at least keep it acceptable enough for you while you save up for the MGM

First... Check your timing on the MM and make sure you set it to the lowest setting. (trust me you will not even notice the differerance in power) Then set you start power to the highest setting you can run without getting cogging on a heavy throttle start up. If you are not set this way already this should help keep some of the heat down in your MM. Next look at your gearing. Many run the 8xl on a MM in an emaxx very sucessfully. If you are getting a hot controller you are likely over geared. Take the pinion down a couple teeth and see if the temps get any better.

[jhautz]

Originally Posted by BLRusty

Yeah I kinda figured that from the start. I knew the MM was not meant for use in 1/10 monster trucks. Its just that I've read that a few people on this forum and traxxas forum run similar setups in their Emaxx's and Revos. A MM with either a 7xl, 8xl, or 9xl. With 12-14 cells, or 3s lipos.

You can easily run 4s lipo on the MM as long as you use a Rx pack or UBEC.

Thanks jhautz.

I was going to get 3s Lipos because I run a MM5700 in a Rustler as well. I have considered getting 2-2s packs, and might go that route now, and worry about my Rustler later.

My Emaxx is geared 15/51 with a strobe slipper kit and mod1 gears. I find this gearing fairly low as it is.

My MM has been programmed with timing to lowest, and I do believe the start power is at its highest setting, if I remember correctly.

And I have been using a receiver pack and MM bec disabled.

The Temps still go up to the 200F range on the ESC, and 160ish on the motor.

This may sound stupid, but I have only recently put foam inside my tires. I bought the rolling chassis off ebay, and the tires were glued without any foam inside, so I decided to run it as is anyway. Could this factor make the temps rise on my MM ESC??

[jhautz]

Well a feigao motor is going to get hot pretty much no matter what you do. Cheap and powerfull, but not really efficient.

I gree that 15/51 is rather conservative gearing already. How much does you maxx weigh? I dont really think the no fam thing would really matter from a heat standpoint, but what tires are you running? What is the diameter? Big heavy tires will make it heat up faster for sure.

Im not sure how much it weights, but it feels pretty heavy when I pick it up. Then again, I am more used to picking up a Rustler, so I dunno. Its not light, thats for sure.

The tires are whatever the stock traxxas Emaxx tires are. Kinda look like tractor tires.

[_paralyzed_]

try a 4s pack and see what happens, my weak link was the batteries and everything acted better when i got "real" batteries, how hot are your batteries when one running? if they are hot you need better batteries

For batteries I've been using two 7cell Tenergy packs. I know, Tenergy right. For some reason these two packs came from a VERY well manufactured batch. I've bought eight Tenergy packs since then and they are absolutely garbage. I've had these particular two 7cell packs now for over a year with close to 100 runs on each. They still pack soo much punch.

Anyway I could go on, but as for temps after a run, they are only warm to the touch. So I don't think my batteries were the problem. It turns out some of my MM settings were set for medium and not high. I've heard this results in a resistor being used to limit power and producing heat. Not sure if thats just a rumor but it makes sense theoretically.

Anyway I've got a MGM Compro 16018 on the way as well as two 3s packs, so, I should be in business!

[Hickoryhead]

Just a quick note. When I set up my EVO with a MM and a 1950 1800kv I found that when I plugged my 2 6000 mah 2s2p (ran in serious) into the MM with an RX pack just sitting the MM would heat up. Yes the MM BEC red wire was unpluged. I brushed my hand against is before I ever ran it. Hot to the touch. After I installed a UBEC no heat issue's what so ever. Just a thought.