another v3 gone

[hoovhartid]

Originally Posted by skyler

Isn't the whole idea of producing a user friendly system for the general public supposed to work comfortably within it's spec? They are releasing this system in an e revo and many people new to bl will buy this and say cool it can run 6s and will run it at it's limits and I really cant blame them at all for that. CC will even warranty the esc if it blows within spec, that itself is saying something about the manufacturers stance on the issue of runnning it at it's limits. That is, it should still work at that range without blowing.

This is a good point, but there is more to consider.

I hate to compair green to orange but here it goes....

The novak hv maxx has recommended gearing suggestions.....while the MMM is still untested on the e-revo. I'm sure in time Traxxas and Castle will give gearing suggestions as well. They will also probably have minimum mAh and C rating requirements for the batteries.

Right now, my opinion is that the MMM is having some failures because there has been no suggestion to correctly set certain vehicles up.

Look at the Mamba Max, and the sidewinder. They both have gearing suggestions for the more popular vehicles they are put in. In time, the MMM will too.

Would you put a pair up a sidewinder ESC with a CMS7700 and run it on 3s lipo? You shouldn't

All I'm saying is Castle has done a great job bringing us more power for less money as fast as they could. They will finish writing the manual one day. I, for one, am happy to help them write it.

[skyler]

It's just I know from working with engineers in the motor industry that when releasing product to the market the spec range is always far lower than the actual limits of the product. You'd find a breaking point at say 1000kg but state the user specs to be ~600kg. If the actual limits of the MMM is 6s I'd be shocked. The limit should probably be closer to 8s. I figured this with the MM as many have ran it at 5s without issue. In other words 6s and 1515 1y Neu should not at all be torturing the esc. And yes as you stated gearing charts, motor & battery combos are also needed.

[Dagger Thrasher]

You have a point, but from my perspective, there don't seem to have been any failures related to actually overstressing the MMM. In fact, I don't think anyone's really come close to stressing it; Castle themselves have run a a 1521 1D on the MMM with 6S which is an insanely powerful and current-hungry motor, and not had a failure.

You can't really compare mechanical safety margins to electronic margins though, IMO. The MMM is designed for a maximum of 6S LiPo, and will run at that voltage perfectly every time, ignoring any other problems. Its components can handle that voltage just fine, with the FETs rated for 30V and caps for 35V, but not any higher because it they don't need to be to run 6S reliably. The input voltage will never stray above 25.2V, wheras in mechanical designs, stresses may temporarily move above its "design-strength" and you have to take material tolerance deviations into account. Castle certainly know about mechanical tolerances; when testing their motors, even the very worst samples were able to hit at least 85,000RPM before the rotors went (with others reaching over 100,000). As aresult, Castle are only rating them to 60,000.

Current-handling ability is where you need plenty of headroom, and the MMM has buckets of that. Only one person has managed to get it as high as 170F when it died, and that seems to be a serious setup error (it would appear so anyway); the MMM shouldn't even thermal until 220F.

I'm not trying to argue or anything, but that's just my opinion.

Originally Posted by hoovhartid

This is a good point, but there is more to consider.

I hate to compair green to orange but here it goes....

The novak hv maxx has recommended gearing suggestions.....while the MMM is still untested on the e-revo. I'm sure in time Traxxas and Castle will give gearing suggestions as well. They will also probably have minimum mAh and C rating requirements for the batteries.

Right now, my opinion is that the MMM is having some failures because there has been no suggestion to correctly set certain vehicles up.

Look at the Mamba Max, and the sidewinder. They both have gearing suggestions for the more popular vehicles they are put in. In time, the MMM will too.

Would you put a pair up a sidewinder ESC with a CMS7700 and run it on 3s lipo? You shouldn't

All I'm saying is Castle has done a great job bringing us more power for less money as fast as they could. They will finish writing the manual one day. I, for one, am happy to help them write it.

Well put Hoov! With 3 publicly reported failures on the v3, 2 of which were in extreme limit pushing platforms, I'm feeling confident that mine will do the job when it gets here. My v2 was almost 70 hours of use when it died, and the firmware update killed it.

[skellyo]

Originally Posted by DickyT

With 3 publicly reported failures on the v3, 2 of which were in extreme limit pushing platforms

Here's where I've got to voice my opinion...

1 of those failures was on a unit that even the folks at Castle said appeared that liquid of some sort was sucked in by the fan. If that's the case, and the liquid caused the failure, how is it related to pushing the limits of the ESC?

On the 2nd failure where the user was sort of pushing the limits, the battery connector came unplugged while he was braking. If a battery can shift enough to pull the connector free while you're driving, it's a poor setup and purely user error IMO.

So, given the facts that have been posted about those 2 specific failures, it's really hard to see how one can draw a conclusion that a setup that pushes the MMM spec limits is really causing a failure.

[emaxxnitro]

Originally Posted by castlemike

If you were in full brake when the battery connector came unplugged, then it probably blew some FET's when that happened. Then you plug it back in and poof here comes the smoke. The voltage generated by braking has to go somewhere, without a battery to dump it into then the controller takes the brunt of it. Battery coming unplugged on a heavy vehicle during a full brake is usually bad.

i talked to my engineering buddie and he said at that motor speed its like a generator, and if anything comes unplugged the energy has no where to go. it will burn it up, that is a very logical explaniton . even without the brakes. its that dang deans plug! i better make the wires longer!

[emaxxnitro]

i went out and re-soldered the input leads so i will not have that problem again

[transtalon]

I think you're wiring are too long. It will create resistance in the system and will cause your wires to run hot. Just my opinion.

[skellyo]

Originally Posted by emaxxnitro

i went out and re-soldered the input leads so i will not have that problem again

Way too much wire dude.

A much better solution would be to buy batteries that are actually suited for the application. Trying to keep all of those packs in balance will be no small task.

[hemiblas]

You guys gotta remember that the majority of the MMM failures were bec related so I am not worried here. These failures dont seem bec related and could be just bad luck. I agree with hoovhartid, I dont think you can just run any combo you like and have it work successfully. Maybe you can and thats great, but motor and gearing must work together based on battery capacity and C rating. It takes a pretty intelligent person and truthful information from battery manufactures to get it right. I think 99% of the people should just be given plug and play setups. The rest of us should be on the RC-MOnster forums.

[emaxxnitro]

Originally Posted by transtalon

I think you're wiring are too long. It will create resistance in the system and will cause your wires to run hot. Just my opinion.

`nah the voltage drop will be 0.5% of full voltage. they are 10g wire, in short thats not enough wire to create a problem with the voltage drop

[TexasSP]

Sorry bud but you are dead wrong. Your calculation is based on everything being to perfection. You have way too many failure points in your setup. That much wiring and all of those connections will cause you problems period. That is one of the worst setups I have ever seen.

Originally Posted by TexasSP

Sorry bud but you are dead wrong. Your calculation is based on everything being to perfection. You have way too many failure points in your setup. That much wiring and all of those connections will cause you problems period. That is one of the worst setups I have ever seen.

Tex...please stop sugar coating it and tell him like it is

[emaxxnitro]

the whole idea of rewiring was to make it long enough so that they will reach. if i dont i will fry it again and again and again! i dont like making castle fix my mmm after i messed up in the first place!
next are you going to tell me my cc 5mm bullets are to small? or my 1515 is not suited for my aplication? i based that calculation on my electricions book, if you have one look under voltage drop.

[hoovhartid]

so your running 6 lipos in one vehicle?
....do you have any pics?

all I picture is this;





just messin with ya!