BL-Revo 9XL + ??
 

I'm going to be running my 9XL with my MM controller on 4s lipo/14 NiMH, but I have a feeling that I'm going to want more voltage for the 9XL.

I'd like to go to 5s or even 6s eventually, so I'm trying to plan out which esc I should get to replace the MM, which is only super-reliable on 4s (so I hear).

I see that many are going with the Quark or MGM for $275+.

Is there any reason I shouldn't go with the BK 9920 for only $125?

Thanks,

Brian

Driving style: bashing, speed runs, maybe racing someday...

The BKs only work with 2 pole motors, so won't work with Neu motors should you decide to upgrade later. Also, the programming is VERY limited and there is no LVC for lipos, so you'd need an external one. Warranty work could take ages if something goes wrong.

The Quark works well, but does tend to heat up. The "internal heatspreader mod" fixes this, but opening up an expensive ESC is not something many want to do. Programming is OK, but can't use a PC. Has a built-in LVC, but max cutoff is 3.0v/cell - some people would like to set a 3.1v or 3.2v/cell cutoff. It says it will do 6s, but no one that I know of has gotten it to do that. 5s is really the limit. That said, it is a very smooth controller and works with inrunners, outrunners, and slotted rotor motors (like the Neu). Customer service is good and fast should something happen.

The MGM runs very cool and can run pretty much anything. The new ones have a built-in switching BEC, so that is one less thing to buy. An LVC is also built in. You can program it with a PC, but not sure it'll be as good as the MM in that regard. There is an issue with reverse and brakes, but only happens at very low speed. Warranty work can take a while.

I think that basically sums it up. :smile:

So, if you had the $275 to spend, would you go with one of the better two or the "hopefully good enough" one and spend the other $150 on lipos?

If I had $275 to spend, it would be the MGM. Both the Quark or the BK needs a UBEC (MGM doesn't) saving you ~$35 right off the bat. The BK doesn't have an LVC for lipos, so that's one more thing to buy and hook up.

I tend to buy quality even if it takes longer to complete a project. No sense spending any amount of money for something that you don't really want because you'll most likely be spending it on the right item in the long run essentially paying twice as much.

Good call. That makes sense.

I think I'll just stick with the MM until the MGM comes back in stock.

Thanks again for all your help and advice!

Brian

IMO, the real limitation you will have on going higher voltage will be the motor before the escs. You can get away with 5S on a 9XL and even a MM (90+% likely) but you will be creating lots of heat with all that power. Personally I thikn the MM will handle 5S better than the 9Xl will (in regards to reliablity and heat.) Forget about 6S. If you want to go huge power, you will need to upgrade to a better motor, like a Neu if you want anything reliable.

I would recommend just staying with the 9Xl and the MM and run with it for a while and see how it suits you. I think you will suprized just how much power that is in a big truck like a Revo. If you then decide you need huge power or are having heat issues, then plan to go to a hi-volt or &/or hi power system all at once. It makes it easier to plan then as you can decide on it as a system, ie consider ESC, motor & kv, and the batteries you will need. Its a bit expensive that way all at once, but you end up w/ parts that make sence with ea other and may be cheaper in the long run. (Ie you invest alot into a 4S system, have 8 AH batteries, want to go 6S, gets insanely heavy to run 6S 8AH batts, so you have to buy all new 6S batts.)

Plus, if you are planning a 2100+W system, you will want to save some $ for diff upgrades. :)

I have been very happy with my quark controllers. I have heard that they do not work on 6s, I only run 5s max anyway. The 9xl will be soinning a little fast on 6s so I would not recommend it as a 6s motor. 5s will be fine though. I had 2 bk esc, a 7019 ans a 9920 and did not like either. Very poor startup and not all that powerful compared to a mm, if that makes any sense. The MGM sounds very promising, but I would like some more opinions on it from the other members. Add a few caps to the mm input and try it out on 5s, just use low gearing for testing. I will be trying that as soon a griffinru gets mine back to me. I sent it to him to do a few mods that should help with heating issues and maybe a little more voltage capability. The mm is a good controller, I have used a stock one with a 7xl in a heavy buggy on 4s with great success!

I'm starting to think that I'd be better off just sticking with what I've got for now and trying an 8XL or even 7XL for more power if I really feel it's necessary.

The 8xl will be a good choice, the 7xl will be a little hot.