Thank you for clarifying Patrick, now is there anyway you can scoot our esc's to the front of the line :lol:

But there are parts on both sides of the boards.... :whistle:

You know, since we are talking theoreticals here, how about this: Design the ESC so the FETs are pointing down. Then, attach an aluminum heatspreader that is exposed to the outside world. Then put four 3mm threaded holes at each corner. Attach an L heatsink or something as the default option (or not, whatever). This would allow people to alternatively attach it to the chassis or their own heatsink. Wouldn't involve opening the case that way. Just thinking out loud...

I know it's reflow I misspoke, we have ours wave soldered, because we still use a lot of thru hole components. I am not saying your product is bad, that you don't use checks on your equipment I am sure you do (especially after seeing the load tester for one of your ESC’s. in another thread:wink:). I think you make a great product, I never said anything to the contrary. And I am not saying you don’t use top of the line equipment, I have worked with many AOI systems (nothing is perfect) as well integrating them in systems we build.

I know first hand about conformal coating and lead free, we are just not there yet. (We don’t sell overseas). To me if the joints at the inductor failed as you described it would have left one of the leads behind. Maybe it did I was just using my experience to make an informed theory on what might have happened.

I understand the amount of shock that these things are subjected to, and you probably have more solder needed for that purpose (since it is known that that is what is going to be subjected to). I understand that you take quality seriously I have read about the exemplary customer service that you have. That’s why I bought my Mamba Max, and in the near future a MMM or a Mamba Max pro for RC and an industrial application in the works.

In my line of work I have seen just about everything (because as soon as you say it, something else comes along) as well I have been with the same company for nearly 15 years and do a lot of repairs, I have seen my fair share of defective components, absolutely wrong installations, people that think the A/D card needs 110 plugged into it, lightning strikes, forklift damage, cards sent in without a thing wrong with them. People who have no business trying to troubleshoot a piece of equipment using a DMM, or any real clue what the problem is in the first place (The old it’s broke, it don’t work deal). Again I am not bashing your product, but to have the same failure mode to me would raise a flag.

Jeff

I agree -- after I saw this thread, I went and asked for statistics from the repair folks here at Castle. They hadn't seen another failure like the one shown here. At that point I had to assume it was a fluke.

But one of my engineering techs (Mike) who is also a racer told me he had seen a failure like that when we were first wringing out betas of the Mamba Monster. It was only a single failure, and it was caused by the inductor cracking (it didn't fall off the board, it just cracked and failed.)

With only three know failures (from about 40K units sold), I can't justify changing the design at this point to address this issue. Maybe in V4. :)

After weighing 100 SMT inductors the mean weight is .1134 Gram at 100 G’s that would be 11.34 Grams (about .4 Oz) pulling against this part. Negating flexing of the board should that be enough to dislodge the component? Did I calculate this wrong?

Reflow is great, but sometimes it’s hard to find a balance between enough heat to properly fuse the larger components without damage to the smaller components. Not saying you should change your process, hell if you only have these three failures then that is great, but as you suggested about G forces I don’t see the component being heavy enough to break from the board unless the board is flexing or it was a bad solder joint. Even at 1 gram the load would be less than ¼ pound.

Regards

Jeff

For the OP- was the missing component found rattling around inside the esc case, or had it completely vanished? That might shed some light on the failure, but 3 of this nature out of thousands is just too random in my mind to be a sign of bad design or soldering or anything else.

Big jump + heavy landing = broken esc > bit of padding under the esc might work wonders, has for me atleast..

Guys! Have some problems in MMM v3 with same elements. Here in Siberia not good with support and I have to repair it myself
Damages 3 elements on foto and I can't find analogues :neutral:

http://img-fotki.yandex.ru/get/4604/...5cde314_XL.jpg
Original

1. Right red arrow. I think this is the transistor 2SC3906K or 2SC4102.
2. Yellow arrow. I think this is a inductor ~ 68 mkH (maybe LQS33N680G or LQG11A68NJ)
3. That a third element (left red arrow) ?

Help please, I want to repair my MMM very very much!!!:cry:

1. NTA7002N
2. 47uh 1008
3. BAT54HT1

Question is - Did you have to check or was that from memory? :whistle:

Actually, that was from memory -- but I think that's correct. :lol:

Pdelcast, thank you very much for the quick response!