Little cooling help for MM Muggy?
 

I've been running my BL Muggy for a while now. It works great, handling is awesome, flies really nice, rarely breaks. It's as fast as I would want it to be (about 40 MPH). My setup is; Feigao 8xl, 14t pinion, Spider Diff, Modded MambaMax, MaxAmps 6000 4s.

My problem is, I always thermal the ESC after about 10 minutes. The motor is pretty warm but not hot. When I stop and recharge, I'm usually putting 3500mah back into the pack.

What's the best way to get the whole pack through it at once? I'm not a big fan of fans:wink: but without losing speed, what are the options? My MM won't run on 5s or I would go that way. Any ideas?

well i suggest you become a fan of fans otherwise your asking an impossible to answer question without modifying and invalidating your castle warranty.

you could remove the castle heatsink and put a larger one on or alternatively buy a more efficient motor like a neu motor or similar.

you could always pickup a mtroniks controller and using thermal epoxy attach it to your chassis for sinking.

other than that until the mmm your Donald ducked if you don't want to use fans.

the spider diff can have multiple spur sizes, we need to know spur gear count and is it a losi muggy? are the diffs 13/43? then we can help more, offhand i'd say drop down a couple teeth on the pinion

he likes the speed as it is though. diffs are 11/45.

You can try using caps on the incoming battery leads (as close as possible to MM), some people have seen reduced temps this way. I would definitely run a fan on a rig that heavy myself. I run fan on my 1/8th buggy with MM, even though it never thermals without a fan.

Two choices - either use a smaller pinion - or get a fan.

My suggestion -

Novak fan: http://www3.towerhobbies.com/cgi-bin...?&I=LXKKN0&P=7

Screw it directly into the ESC and if you have an extra channel on your receiver, plug it directly into the + and ground and you'll be set to go.

Also - depending on the location of you ESC mount cut some holes in your body to encourage some air-flow over the ESC when running.

spur
 

I just counted. It's a 46t spur. It's a losi Muggy with Muggy diff gearing. I guess what I'm really wondering is how much of a gearing change would it take to make the difference. If I could give up a little top end speed, that would be a fair trade. The torque is already more than I need but there is a little cogging from a dead start.

what size pinion you running now? (*edit*,saw it) I would try dropping one or two teeth. If the torque is already too much, try using some punch control, it may keep things a bit cooler as well.

1 tooth drop on the pinion would not be very noticable and may help heat issues. 2 teeth would most likely do it, but that would knock off a few mph.

Just get a novak 2700 cap and solder it to the main leads close to the board. That may do the trick, and costs about 10 bucks!

Also, reattaching the heatsink properly will help too, the stock thermal glue is not applied very well.

using the speed calculator going to a 12 tooth pinion drops off 5mph, but how often are you at top speed? that should help your cogging too.

Another question - what are your MM settings for the following:

Punch Control

Motor Timing

Startup Power?

I've had several conversation with the Castle guys on the phone and the "Normal" setting for Timing is like a 10% advance on timing. They recommend setting the following:

Timing - Lowest
Start Power - Low
Punch Control - up to the batteries you are using. If you have punch control set at 0, try kickng it up to 30% and adjust it from there.

I would run a ducted fan over it like my friend does. It cost the same as a regular fan yet puts out a alot more wind and is very efficient. Here- http://www3.towerhobbies.com/cgi-bin...?&I=LXHHP1&P=7

Hmm, just use a larger ducted fan unit, place the esc in front of it, and use it for thrust. I would think that a 1515 powered ducted fan unit would be reasonably powerful, and the intake would flow plenty of air over the esc...

I have the same exact setup. 8XL, stock diffs, 4S 5000 lipo and I started with 16T but dropped to a 13T because of temps and you'll probably have to run a fan. I also mounted my MM on the rear shock tower plate so it gets plenty of cooling with the stock body. I also added an HV Cap which I think helped also.

http://i160.photobucket.com/albums/t...y/CIMG0417.jpg

Hmmm... I would just go for the small ducted fan because its cheap and you dont have to mod anything. "Much Easier"

I never understood why so people are against using fans. Even if you are geared correctly, the cooler the esc the better.

what mods are done on your esc.

the cap should help some , and also put some holes in the case

Cooooool
 

IMO I would go for what is easy and takes the least amount of work, but gives you the best results. Try adding the cap to the power leads and instal a cheap fan. With those two items you should have a much better setup without compromising speed.:lol:

I don't know about other people's reasons, but I don't like them because A) adds wiring complexity (albeit small), B) Just something else to go wrong, and C) if you are relying on a fan for reliable operation, then if it breaks/goes bad, you generally don't know it until you thermal.

IMO, fans are for an improperly designed system. With adequate airflow and/or a little extra heatsinking, any ESC should run right. If not, either gearing is too high, battery voltage or ESC current rating is too low for the power you want, or any combination of these.

And this is from someone who doesn't like temps any higher than 30-40*F above ambient temperature.

A) I think the extra wiring is negligible. B) True. C) I agree a fan should not be used to compensate for bad gearing. However, adding a fan to lower the operating temp is always good. Even if the esc is only 30* above ambient a fan might lower it 10-15*. Lower temps means longer component life and more efficiency.

I too like lower temps, which is why I usually add a little extra heatsinking and try to orient the fins so the airflow goes through them. So far, this has worked very well for me...

But hey, to each his/her own, right? :smile:

Its for safety reasons... You could have the most perfect gearing possible yet something could go wrong later on in the run and you not know it and the next thing you know your out $200 or more.

How do you take the case off the MM? Does it just pop off?

Their is two small hex screws holding it on. One behind the capacitors and one on the other side of the MM infront of the heatsink.

Tires!
 

I put the low profile Muggy tires on instead of the LST2's. Instant improvement. Now the temps stay good, runtime is 20-25 min but I still have to actually time it now that I'm not overheating.



Note to self: you're not a good enough driver to drive between parking blocks at high speed.:oops: