I just clearanced the bottom of the case so that the plug would not touch it. Then I made some foam "suspension" pieces for the pcb and put it under the larger wire solder points. So far the fan still works, so I guess the plug is stll intact... I need to pull the esc back out and see how the fan wire is doing. I wonder if it has frayed yet, as it sits between the pcb and the case...

thanks guys for the good info here

The MMM(v2) that I have with the most hours on it now (of all MMM's I've had) is the one that the fan connector broke off of on the first day I ran it. I took this one home after it broke, removed the fan & broken off connector and replaced the fan with one that plugs into the RX. This one is holding up great. I'm starting to think the the fan connector getting banged on the case & into the brain board may be what is causing some of the BEC's to fail.

Well, patrick said many V1s suffered from a bad batch of BEC switcher ICs IIRC. But that aside, the jarring of the connector on the case could put hairline cracks in the PCB, and if it's a multi-layer board, the bad traces could be in the middle or back layer and you'd never know it.

Personally, I like adding "spacer foam" to the PCB itself and keep the bottom whole so that mounting isn't affected (reduced surface area). Unless you make a hole in the case, and then glue another piece of plastic on the bottom...

Funny, my fan plug broke off just trying to pull the fan off. Whatever, I was planning on running it off the the rx anyway.

Instead of modding the case, I made a case mount that solved a couple of problems I had with my V1s. It now has a quick change fan on top using a 25mm Muchmore Racing fan that I've had good luck with on my MMs. Second, it keeps the case from popping apart. And third (just in case), it's a fire shield for my lipos! :lol: (just kidding Patrick!)

http://i21.photobucket.com/albums/b2...e/DSCF3448.jpg
http://i21.photobucket.com/albums/b2...e/DSCF3443.jpg

I was rushing when I made it and broke my 3mm tap on the last hole, so instead of a nice countersunk screw, it's a dowel pin. :oops:

clean job,,!!!!!im always surprized when i see a mmmv2 (working unit:yes:)

and aluminium is pretty hard to tap a small screw size:whistle:

hey mike, i just got a second MMM, running great so far

though i would hear the fan rubbing the case at times

thats a great idea

brushlessboy16....lucky you are ...:yes:me my second v2 failed after 30min....:party:friday....(i ship today to cc)i have one unit that my friend david lamontagne sold to me...(he run it about 2 hour so far)


lets see what happen this wek with this unit....:whip:

Hey Mike, we were discussing this on Sunday at Bayside, but later last night I was thinking about this...allegedly, there are alot of burnt V2's from right when guys are calibrating or RIGHT when they start running them (slow). That is, they wouldn't have caused any jarring to make the PCB flex causing a broken solder. So, while I do think the plug is a problem, and has perhaps caused problems, there must be another possible cause in addition.

:yes:

I modded my case before I powered up my V2, I removed some material from the bottom of the case to make room for the fan connector and I also did a small amount of relief work for the induction coil. Regardless the BEC failed just after calibration with my radio. I beleive the case is a problem and is possibly causing a few malfunctions but believe a more likely explanation would be

A: Faulty parts
B: Assembly fault (my money is on this)

I would think that after all the V1 failures that the CC techs would of gone over the design of the BEC with a fine toothed comb. This leads me to believe that the same problem from the V1's is also effecting the V2's. Is it possible an assembly technique is to blame here?

Has anyone noticed how close the control board is to the back of the FET board? I wonder if when they solder these boards together there is some sort of issue???

Just some observations... I love CC :love: regardless

What are everyone else's theories????

I received mine (v2) as maybe the 1st or 2nd sent to us customers (not including beta testers) it was sent back with my original connectors from 2.5 months earlier, all nice in small (dime bags) lol. This thing has been flawless. Its soldered very nicely, who ever delt with my particular case spent a fair amount of time making everything right. I said in another thread my theory is sabotage. Some loser soldering joints together too close works too

Ya Pete, I agree. There is at least 1 more problem that is NOT related to the fan clearance/fan wires/fan connector mechanical problem. Another issue I could see causing problems is the heat sink being to close to the 6.5mm sockets. On one of the Monsters I have the heat sink is so close to the battery sockets that I could barely get a peice of electrical tape between them.

2nd the issue with the heatsink - I think CC should go back to soldered wires. The cups are way to close - I would say touching the heatsink.

The only thing that I believe is stopping a short is the laquerer that is put on - however when cleaning the esc with buggy blast and a compressor most of the laquerer came off so VERY worried about picking up a short.

Personally leads are fine by me....

I like the cups. I just put some e-tap on them.

Not sure I could get tape or shrink down the back...

weird, mine are spaced out far enough to get at least tape perhaps a bit of heat shrink. I hadn't thought of this at all actually. thanks for bringing it up!!!

edit: u know, both the fins near my battery terminals are bent! this means they are touching/have touched.... also at the bottom i think the esc IS attached to them... im sure they would have thought about this a little???? perhaps its impossible to short for some random reason..?

Well the heatsink is 1 peice of metal & if both your battery socket hit it at the same time, that's a dead short across your battery. :gasp:

I've been following this thread. Very interesting points you guys are discovering. Jhautz also showed in detail about the possible fan plug issue.

I opened mine back up to check out the heat sink you guys have been discussing. I felt it was worth pictures. Here they are:

In this first picture, please notice that my motor power cups have ample spacing.
http://i160.photobucket.com/albums/t...m/DSC07189.jpg

In this picture, my power lead cups are touching the heat sink. Bent heat sink pins as previously mentioned.
http://i160.photobucket.com/albums/t...m/DSC07190.jpg

This last picture shows the lower case mod that I did to create clearance for the fan plug. IMO, it's not necessary to go completely through the plate.
http://i160.photobucket.com/albums/t...m/DSC07191.jpg

Please Note: In the upper right hand corner of this last picture, I found a resistor riding right on the support rail. I also removed material to clearance for that.

What can I do about the power lead cups touching the heat sink? I don't have a good feeling about this. Those pins will flex/rub under shock and vibration I'm sure. IMO, this should have additional clearance to prevent problems.

Replace the connector with wire leads...

thus voiding the warranty. ill just leave it be, and if it fails -its castles fault!!! but with them touching (look down the bottom, its almost glued to the heatsink...?)

u could always just cut the fin/s off?

Well yeah, but I didn't realize the warranty was a factor. :wink: And I think cutting the fins would void it as well.

not as bad :lol:

but until castle figures out everything eslse and we see the new case design these are here to stay imo.

Would heat shrink work?

After this potential problem was pointed out in this forum, that's what i did. However, some of the posts were so close to the heatsink that I had difficulty to insert the shrink. In addition, the shrink also interfered with the case. Had a difficult time putting back the case.

I'll try to put up a pic later for more clarity.

Regards,
Joe Ling

Novak Glitch Buster Capacitor
 

Do you think Novak Glitch Buster Capacitor will reduce possibility of failure?

It is supposed to "store power from the Battery Eliminator Circuitry (BEC) and act as a filter to eliminate noises generated by servos" and "reduce load on BEC".

Do you know parameters of that capacitor?

Depends on what is causing the failure. If it's simply amperage load, then no, it won't help. If it has something to do with filtering, then maybe. If the issue is with a bad BEC component, then no.

A cap inherently stores a charge and filters out AC. So, it provides a "reservior" of sorts that will help with current draw when servos need more peak currents. However, if the load requires a constant high current, a cap won't help much at all. It also helps get rid of noise that may be present on the BEC output. However, if the noise is getting in elsewhere (antenna, throttle/steering signal line, etc), it will not help.

Don't know the parameters of that cap, but $13 plus whatever the shipping costs are is a bit overpriced IMO. Just go to RadioShack and pick up a 1000uF (or higher) 10v (or higher) capacitor and solder a servo lead to it.

Here is another option. Marketed for a different reason, but essentially the same thing. A capacitor on a rx plug. less than $5 too.

http://www.amainhobbies.com/product_...oducts_id/6570

I have just bought 6,3V 1000uF cap. Unfortunately not SLR.

I hope that simple (13 cents value) mod will lower possibilty of failure. Keep your fingers crossed tomorrow :)

Base of heat sink in my MMM V2 is touching battery connectors :/ I hope little silicone will prewent short-circuit.

I hope I am in happy 50% of MMM owners ;) It works, with some mods, after at least an hour racing. Peak power with Medusa 60-1600 on 6S A123 was 1807W :)

well, after my case mods and adding shrink around the bullets, as well as using a UBEC...it didnt matter.
My 2nd MMM v2 took a dump. :(

I'm gonna roll the dice on a MM with a BEC and a fan.

Unlucky, haven't heard of to many going up in smoke using a ext. bec

I think your's is the first to take a dump using a UBEC.

No he's not

It didnt smoke actually.

It just stopped. It was running, then it wasnt. I thought I was seconds away from seing casper so I stopped pulling the trigger.
I took the lid off the truck and she was just sitting there.
Checked all my wires and connections, plugged in the castle-link and nothing. she was completely dead.:neutral:

Smells so too. it was indeed odd to have that fried electronic smell and no smoke.

:lol:I dont think you should be telling people that you sniffed my electronics.:lol:

you had to go and put it that way..... you're bringing the beer next time too for that one :P

so what? now I need to get you liquored up first?:rofl:

I quit, before the crevasse I have created is too large to climb out of, you sir have sharper with than I :na: