One last thing... if you have cogging at only 1/2 throttle or less... then imo that pretty much proves it's NOT the battery.

Castle can't blame a battery that can put out 200 amps when it cogs at less than 50 amps....

i know that you tried moving the receiver around, but could it be a transmission or interference problem. Mine runs fine most of the time, but when I drive it in certain areas it cogs. It happens every time when I do a speed run on my street as I am turning around and starting to come back on another pass. I wonder if it is a problem with the connection between the radio and the esc?

GD, thanks for the post. I believe that I read someplace on this forum that I'd lose something over a pound of weight going with the Maxx type tires. I guess I really have to keep in mind that this truck weighs a ton in its current form and getting all of that weight (and the rolling mass of the wheels/tires) moving is a chore for the motor/esc.

I haven't had any problems with the MGT conversion, but on the other hand it is geared very conservatively. It tops out at around 25mph, but gets there in the blink of an eye. At this point, I don't mind sacrificing speed to get the big truck moving well and without cogging.

It is warming up down here. Actually, it's starting to get hot and yesterday I noticed that the esc is running noticeably hotter than the motor, so I'm figuring that I'm still overgeared. I guess these monster trucks aren't built to go fast. Maybe I should have set my sights on a Revo, rather than this 13lb monstrosity.

OK...you might be able to tell that I'm starting to get burnt on this issue. The conversion didn't turn out the way I wanted. Unfortunately, I have to figure out what I'm going to do now. No one down here is interested in a Muggy, because everyone is still hot for the 8ight/T.

Another thought that I had was maybe going with a bigger motor. Maybe a Lehner 1950 series. I think that there is a 1700kv model. Perhaps that would be the ticket in being able to get the truck moving without all of the cogging.

No matter what motor you get, the current load on the ESC won't change (at a given voltage). If it takes, say, 500w to push that truck around to a certain speed, it will still take that same 500w, so the ESC won't get any cooler. Going to a bigger motor will make the motor run cooler, but not the ESC. Gearing down, using smaller tires, and lightening the weight will make the biggest difference to the ESC. Or going with higher voltage and a higher turn motor will work too.

Sometimes conversions don't go the exact way you want, but that's part of the fun treally. It's just a matter of finding the combo and setup that works the best. "Back to the drawing board" as they say.

Now that I think about it, the becs that I got had a magnet twisted up in the lead wire to eliminate interference. I wonder if that might have something to do with it.

Anyway, as I said, I did find that the lower I go on the pinion, the better the problem gets. I think that this shows that I do need to "go back to the drawing board" with this project. 13+ pounds is a lot of weight to get moving. I know that GD has his running pretty good, but I'll bet that his doesn't weigh anything close to 13 lbs. Knowing GD, he probably has his registering negative numbers on a scale. LOL.

I went and got a set of ofna 28mm offset wheels and some Bowties today. I glued them up and then remembered the 20mm lugs. Crap!!! I lucked out and found a set of those adapters that ofna made to turn a buggy into a truggy, in my box. I just popped the retaining pin holes in them on the press and turned them down on my lathe. Anyway, they (bowties) are considerably smaller in diameter than the stock Muggy tires. If all runs well with those, then I'm set. If not, I'll be looking into a 5S or 6S setup with a higher turn motor.

I also wanted to mention this. I put my setup back in my buggy. The MM/7XL that is. I put the 14T pinion on it and did an experiment. Nailing it from a dead stop is something that I've never done before with my buggy. I suppose that I just don't race or bash that way, but I tried it tonight. Sure enough, in about ten tries, on the last one, it cogged really bad and then stripped the spur gear. Pulled the 14T off and put the 10T on and no problems. I then pulled the 7XL and put the 8L in the buggy. Went back to a 12T pinion, which is what I usually ran with the 8L. No problems at all. Went up to the 14T pinion and it started to show slight signs of cogging.

Would going with a better controller do away with all of this non sense? I'm liking the Compro and the Quark 125b.

Thanks guys.

Someone from Castle Creations might tell you the reason for the cogging is that you are using a motor other than the MM ESC comes with. CC says that the MM was designed specifically for their motors. For a while they've been working on an update that will allow all motors to run on the MM ESC (including Neu and Novak motors).

The "magnet" is actually just a ferrite material used to supress RF noise from confusing the receiver and/or the ESC. I suspect the cogging people are noticing is from less than ideal load (gearing, weight) on a given motor. The 7XL can pull a substantial amount of current especially on heavy acceleration so any efforts to reduce the load (and therefore current draw) on it somewhat through gearing, reducing weight, and using smaller tires will help a lot, as you've noticed.

My Hyper 8 buggy is kinda heavy at something between 10-12 lbs, geared with a 14T pinion on a 2600 KV Neu motor and I never have cogging with the Quark 125. Personally, if you're in a hurry, I'd get an MGM or Quark to get your setup running right. However, if you can wait, the MMM sounds like it might be a better and cheaper choice - that is if it ever comes out.

MM,

This is part of the last response that I got from Castle,

Apparently, he (Joe) doesn't think that going with a different controller will help. I'm inclined to disagree, especially in light of BrianG's post above. It would seem that the Muggy is just stressing that little MM beyond its capabilities. I'm thinking that a "better" controller would know what to do when a lot of current is demanded of the system.

I got my bowtie MTs on today on the Ofna wheels. I'm running 10/46 gearing and even when it does cog a bit, it just takes a split second and then takes off. I'm not stripping spur gears anymore.

Did you tell CC what motor you were running, weight of the vehicle, and gearing ratio? They may be assuming you are running a lighter and/or lower geared application.

Just the fact that it is running better with more conservative gearing shows that the ESC might simply have been loaded too much before.

It may be that the ESC was "weakened" when you were running it hard before (when it cogged badly) and now it runs better, but not as good as a new ESC. Depending on what it going on when it cogs, that could be pulling LOTS of current and may have been beyond the ratings of the ESC. Seems kinda far-fetched but could happen I suppose.

I did inform them of what I was using the esc in. I told them about all of my vehicles, just to try to make apples to apples comparisons of what was going on. I don't think that the esc is damaged. It's actually brand new. It's running fine now though.

I just got an email from Mike, regarding the compro and quark controllers. If I can scrape the spare cash together, I think I'll grab a quark. I'll just have to make a new esc mount for it that will help to sink heat and accommodate a fan or two.

Well, whatever ESC you choose, good luck and let us know how the new one works...

Well, as I said, I had narrowed my choices down to either the Quark or the Compro 16016.

In weighing the pros and cons of each, I considered a few things. My first choice was the Quark, because a bunch of guys here run them and have had good results. Mike (RC Monster) also spoke highly of this controller. When considering the Quark, I paid extra attention to the cons, to make sure that they wouldn't outweigh, the good.

The first thing I didn't like was the fact that it won't actually do 6S, like it's supposed to; and they (S&T) continue to advertise the controller as a 6S controller. I'd rather have a controller that is accurately rated or even under rated, rather than one that is over rated. The second thing I didn't like is the heat. Although I've done more work on electronic components than most, I am far from being well schooled in the field of electronics; however, I do know that heat is wasted energy. Even Mike, who praised the Quark, acknowledged that the Compro is one cool customer. To me, this means that the Compro does its job more efficiently and with possibly better components (or more specifically, components more suited to the job).

When I looked at the Compro, the only real downside that I saw was the programming interface. Oddly enough, I downloaded the manual and I didn't find it to be that hard to understand. I suppose that being of asian decent on my mother's side has helped me here. If I can understand what my mother is saying in english, I suppose that I can decipher anything.

The bottom line is that I ordered the Compro 16016. I know that warranty work will not likely match the speed with which a Quark problem will be handled, but I liked it better in the end. Besides, the price was right, and I'm sure that Mike could help to expedite things if I should need to send it in. At $235, I thought it was a good deal. The Quark at $280, plus another $30 for the heatsink, and another $15 or so for fans and connectors, didn't seem like much bang for the buck at $325.

If my logic is flawed, or if you know of any weaknesses in the Compro that I might not have considered, please let me know.

Thanks.

The heat thing on the Quark is most likely due to the lack of heatsink area (very shallow fins and not many of them) and the way the FETs attach to the case. And I don't particularly like the fact it is rated for 6s when it won't do it. Personally, I liked having an enclosed ESC after having a BK Warrior.

If all goes well, you won't have to deal with any kind of warranty issue. I'm sure you'll be more than happy with your purchase as the MGM is not a shabby ESC by ANY means.

I'm interested to see how it works. I have an old MGM 120 and I don't think it has ever cogged. I have to assume the brakes are indeed fixed from my version. If so, then it shoudl be a nice controller.

Overall my MGM is not as smooth as the Castle and Quark, in the throttle and brake "feel". But it is going in a truggy, and it's certainly smoother than any nitro ;)

At this point, I'd be satisfied to have a system that doesn't cog. I've been looking around the net trying to find some information and I haven't been able to find another brushless Muggy. The Muggy does weigh a bit more than your run of the mill CRT, or 8ight T. Perhaps I've just found the limit on the MM controller. I really don't know.

I was running our track tonight. Geared 10/46 with the Ofna 28mm offset wheels and bowtie MTs. We have a kinda large triple almost immediately after a 180 degree turn. I was in a groove, so I tapped the brakes and slide through the turn whipping around it and then gave it throttle to set up for the jump and...it cogged. Stripped 4 teeth off of the spur. I'm sick of this!!!

GD, from what I understand, the braking issue isn't an issue any longer. MGM is also claiming 1024 steps in the throttle, so it should be pretty smooth. I hope so anyway. I hope it's at least as smooth as the MM. I do like the MM, but the cogging is killing me. Actually, I can live with the cogging, but changing spurs is getting to be a PITA.

I hope that Mike ships my order in the next day or so. If he does, then I'll have it by the weekend. Maybe I should have ordered more spurs too. LOL.

BTW, I ordered four 10Ah cells today from Maxamps. I was looking at the 4S2P 8Ah pack and realized that the 4S 10Ah pack is only a tad bit wider than the 8Ah pack is tall, so I'm going to set the 10Ah pack on its side. I think that should be a good compromise between runtime and weight when compared to a 12Ah 4S setup.