WARNING! A new way for MMMs to fail including your precious V3!

[macr0w]

When I first saw the bullets on the newer MMM's I thought it was cool, until I installed it.

I would much rather have wire directly soldered to the board.

The bullets are just one more connector we don't need.

Not to mention the clearance issue. In a Revo or truggy I guess it's not such a big deal. But in a buggy with a tight body it is a big deal.

Gimmie my old style wires back.

I took the bullets off of my v3 and direct soldered the wires to the female side of the bullet at 90 degrees. So far so good.

[lincpimp]

I do remember that Patrick mentioned testing the MMM and that touching the heatsink to the bullet connectors did not do anything. He said that they could not cause a failure when they tested this issue...

I bent the fins away from the connectors on my MMMs but I may also put some shrink around them too. Time to take them all apart again!!! Whoo hoo.

[lutach]

Originally Posted by Unsullied_Spy

I remember reading that post, that was pretty stupid that it came like that. IDK how it passed QC unless they don't check their ESCs before shipping them.

I'm still thinking if I should take the plugs out. If I do, I'm going to direct solder wires on there, but not facing up. I'll have the wires laying down and make a hole so they'll exit from the back. I would reather have them like that as most application will work better that way. It should be an option that the customer can select how they want there wires to be and if they want plugs and all.

[Dagger Thrasher]

Just a warning guys...you'll need a super powerful iron to desolder those bullets, and with the amount of copper in the PCB, you risk melting solder on other components on the board (as I once learnt with my MM). If this is really causing an issue, I'd just bend the relevant heatsink prongs out of harm's way, and maybe just shrinkwrap the plugs IMO?

I must admit, I can't see how a that socket would've been able to flex the PCB so much as for it to touch the PCB as it's so light (it would take a relatively high impact on the plug for that to happen...or at least, that's how it seems to me), so from where I am it sounds more likely that the plug slipped out and shorted. But even then, Patrick's said this shouldn't be able to happen, so I dunno. Strange...

[lutach]

Originally Posted by Dagger Thrasher

Just a warning guys...you'll need a super powerful iron to desolder those bullets, and with the amount of copper in the PCB, you risk melting solder on other components on the board (as I once learnt with my MM). If this is really causing an issue, I'd just bend the relevant heatsink prongs out of harm's way, and maybe just shrinkwrap the plugs IMO?

I must admit, I can't see how a that socket would've been able to flex the PCB so much as for it to touch the PCB as it's so light (it would take a relatively high impact on the plug for that to happen...or at least, that's how it seems to me), so from where I am it sounds more likely that the plug slipped out and shorted. But even then, Patrick's said this shouldn't be able to happen, so I dunno. Strange...

I did bend some fins back, but when you look at the pics I took the part hat is touching the plugs is the bottom of the heat sink. I haven't ran my MMM yet and if Patrick need to look at the problem it has, I'll be more than glad to send my Monster for him to inspect it.

[Ryu James]

Originally Posted by stum

I'd be surprised if Castle covers this w/o a fee.. you obviously took the plastic cover off changing castles design and voiding the warranty. With the heat shrink that castle has on the motor output wires and the support the plastic case gives near the top it keeps this part from moving at all, I say the only design flaw is in your own changes from the looks of it. I guess we will see, but I've been running MMM's since the first batch of V1's and never had this issue, still have a v2 going strong in my erevo and 2 v3's in my 8ights (truck and buggy).

PS you may want to try a new mounting location in your 8t

this problem has nothing to do with modification. i have a v2 still going strong too. i love them despite the ones that have failed. my motor lead wires are have heatshrink on them but that doesnt matter if either the female connector is up against the heatsink or if the male portion of the connector decides to come out and rattle against the heatsink/female connector at the same time. there isnt heatshrink on the part that inserts into the connector, remember! and go look more closely at your unmodified MMMs. there is nothing between the connectors and the heatsink. there is a little plastic between the connctors themselves but nothing stopping them from hitting the heatsink in a hard hit. think these things through, stum.

[Ryu James]

Originally Posted by lincpimp

I do remember that Patrick mentioned testing the MMM and that touching the heatsink to the bullet connectors did not do anything. He said that they could not cause a failure when they tested this issue...

I bent the fins away from the connectors on my MMMs but I may also put some shrink around them too. Time to take them all apart again!!! Whoo hoo.

really, they tested this? hmmm. well, remember guys, this is probably a rare occurence but i thought everyone should know. i am not sure if this calls for de-soldering and everything but i dont know. maybe thats the best route. it seems we have been having to mod the MMMs since day one to make a better mousetrap, huh.

[RBMike]

Ya he said that but I bent the fins on the heat sink & put shrink tube over the bullets anyway to avoid this.

[BrianG]

Is there enough space to slide a piece of lexan (or any other non-conductive material) in between the connectors and heatsink? If there was constant rubbing, anything would get worn away, but sounds like it just needs a little barrier sometimes...

[bl-is-future]

i still like the way the v1 was with wires. The bullets just seem to add a huge pita.

[BrianG]

I agree. I was thinking about removing the HS on my MMM, resoldering the wires so they are on the other side of the PCB, and attaching the FETs to an aluminum tray/mounting plate/heatsink. Similar to how the Quark is designed...

[JerryF504]

Honestly, to me, it doesn't look like the problem was the bullet shorting to the heatsink. To me it looks more like there was excess resistance in that connector that caused the it to melt. I had some excess resistance in one of my bullets but I caught it in time because it was on the battery side and the symptoms were obvious. Being on the motor side I'm not sure how noticable the symptoms would have been. It looks like the biggest part of your bullet that is burned off isn't even on the side of bullet closest to the heasink.

[ravin]

Originally Posted by JerryF504

Honestly, to me, it doesn't look like the problem was the bullet shorting to the heatsink. To me it looks more like there was excess resistance in that connector that caused the it to melt. I had some excess resistance in one of my bullets but I caught it in time because it was on the battery side and the symptoms were obvious. Being on the motor side I'm not sure how noticable the symptoms would have been. It looks like the biggest part of your bullet that is burned off isn't even on the side of bullet closest to the heasink.

I agree.

What no fan? Anyways I too think the bullets are unnecessary. I would love wires with plugs on the end.

[SpEEdyBL]

http://www.rc-monster.com/forum/show...599#post224599

I like the onboard bullets. Cleans things up a bit, and there are only 3 solder joints on each route going to the motor instead of 4 with plugs on the wire.