I think I fried my MGM - RC-Monster Forums

joeling · **I think I fried my MGM -** 05.14.2006, 08:51 PM

Hi,

Yesterday was a very eventful day for me. First, I think I fried my mgm 160 controller, then the flywheel of my STS engine became loose & after that I crashed my plane.

I was running my nitro buggy around my usual bashing spot / track near the go kart track when suddenly, the engine died. Upon examination, the fly wheel was loose. I am pretty new to nitro so had to seek advise on how to take the clutch assembly out with the loose fly wheel. Spent an hour last night to fix this.

Then, I flew my brushless slow stick in windy condition in the go kart track (track was deserted at the time) & managed to crash the plane beyond the fencing parameter in the jungle. Luckily or unluckily, the crash spot is full of grass taller than a man & the plane was undamaged. However, reaching it was a problem. Had to pay a brave soul to retrieve the plane.

Prior to all these, I think I managed to fry my MGM controller installed in my 1/8 buggy running 5S lipo & 10L. The controller just cut out suddenly & I heard beeping sound indicating some kind of fault. I switch off everything & waited for it to cool. After about half an hour while I played my nitro buggy, I tried to fire up the electric buggy. There was no drive & the red LED onboard the conroller was lit continuously (not flashing & no beeping). 3 days ago, I tried this system out for the first time & I encountered over current alarm. I am under the impression that this esc can handle 160A continuous while the 10L is supposed to pull only 61+A right ? So, I'm pretty concerned. What do you think ? Should I send it back to Mike to have a look ?

More alarming is that I have damaged 2 BK9920 & now the MGM 160 in my buggy setup. Not sure what exactly is the problem. I think I may need to gear up (change spur to 50T instead of 46T now mated with 13T pinion) and seek a better controller. I have been eyeing the BK 12020 & the quark (the big one with 125A capability) esc but the recent experience with the MGM rattled me. I am starting to think that no esc can handle the buggy. Maybe it's the weather here as I live in a tropical country where temperature in the afternoon is still 30+ deg. C.

Need your advise thanks.

Regards,
Joe Ling
Malaysia

PS : while it worked, the buggy was wickedly fast & jump damn high & far.

joeling · 05.14.2006, 08:55 PM

BTW did I mention I was feeling :confused: :012: :026: :019: :002: all rolled into one yesterday ?

Regards,
Joe Ling

Mike.L · 05.14.2006, 09:01 PM

man you've been getting quite a bit of bad luck lately.
sorry to hear....

MetalMan · 05.14.2006, 09:21 PM

5s Lipo is a lot for the 10L! Most people usually run 4s or 12 NiMh cells when they use the 10L. I don't know if that is your problem or not.

I don't know if there is much that Mike can do to help. It might end up being easier/faster just to send it directly to MGM and hope that repair doesn't take 6 months like it did for me.

Another controller you might want to try with your 10L is the Mtroniks Genesis Truck. You can only use up to 4s Lipo with it, but it's waterproof. This may help since you say that you live in a tropical climate, especially with the moisture in the air. Mtroniks has great customer support if you do manage to fry the controller.

SpEEdyBL · 05.14.2006, 09:40 PM

I wouldn't automatically assume that your controller is fried, unless their is smoke coming out. Try resetting it first and check your connections.

MetalMan · 05.14.2006, 09:56 PM

SpeedyBL is right. My MGM Compro 12012 (non-heatsink version) looks like it might be fried by the burn spots on the heatshrink. But, I think this is just from the BEC chip, as the RX cable from it shows the full battery voltage. Otherwise, it works fine!

joeling · 05.14.2006, 10:32 PM

Hi,

I have tried to do the reset to factory setting but no luck. Just a red LED indicating something is not right.

I'm resigned to having to look for another more capable controller. Sigh.

Regards,
Joe Ling

MetalMan · 05.14.2006, 10:58 PM

It's strange that MGM doesn't even have an error code in the manual for a solid LED. You can contact MGM via email and ask them if there's anything different you can try.

joeling · 05.14.2006, 11:42 PM

Dear metalman,

Thanks for your advise. I have just emailed MGM. Hope they reply my mail. In the mean time, I'm looking at the Quark 125A esc. I read that someone over at radiocontrolzone has one in a hyper 8 & he did 15minutes in it without problems with high gearing (14/46) but only on 4S lipo. High gearing is the one that with cause high current draw yes ? The cell count should not be the problem causing esc failure (provided the esc can hanlde the voltage). Is this a correct assumption ?

Regards
Joe Ling

MetalMan · 05.14.2006, 11:56 PM

If a motor is past its efficiency range (RPM past 40,000) or has high gearing, it can pull more current than normal. Higher voltage than what the controller is rated for can be a cause of ESC failure, but this wouldn't be an issue for you.

cart213 · 05.15.2006, 01:13 PM

A 10L on 5s lipos should be spinning at 40~45,000 rpm. That's not unreasonably high, and I can't believe that it could fry a 160 amp controller, assuming that everything else on the buggy is operating correctly. If you've broken 3 very capable controllers on that buggy, then something strange is going on. How hot did the MGM get when it cut out? Was it hotter than it normally is? Were you running in different conditions than normal? Have you checked your drivetrain to see if it spins smoothly? You should go over every inch of your buggy to make sure nothing is abnormal.

coolhandcountry · 05.15.2006, 08:20 PM

Is the escs takening alot of jolting. I was wondering if the vibrations or jolts from jumps are getting to them. It is just an idea. Have your tried another radio on it.

joeling · 05.15.2006, 08:26 PM

Dear cart123,

Thanks for your advise. I will have to check the buggy thoroughly b4 I put the blame on the esc. I also have this sinking feeling that the 30+ deg C ambient temperature during my play time has something to do with the failure. I'm glad to hear that 5S on 10L is ok as this is needed to impress the heck out of the nitro guys. Imagine buggy tires ballooning on command :027:

Regards,
Joe Ling

Gustav · 05.15.2006, 08:50 PM

Quote:

Originally Posted by coolhandcountry

Is the escs takening alot of jolting. I was wondering if the vibrations or jolts from jumps are getting to them. It is just an idea. Have your tried another radio on it.

That was my first thought too remembering your video joeling,those were some big jumps to flat.The controller should be able to handle your setup.the heat and humidity could be a factor but unless it's been running very hot then my guess would be the shock/impacts.

joeling · 05.15.2006, 09:47 PM

Hi coolhandcountry & Gustav,

Thanks for the input. Yes, the big jumps were done using the BK 9920 cable tied to the rear chassis brace. However, for the MGM, I have fashioned a small plate out of some spare blank PCB secured using 3 screws where the radio box used to be. This plate is lifted a little above the chassis using 3mm nuts. The esc sits on top with double sided tape & a couple of big cable ties round the plate & esc. Last I check, it was very securely fastened.

In hindsight, I have also used heatshrink to cover the esc with cut outs for the 2 heatsinks. Maybe this was causing the thermal overload. I noticed that in the end, the heatsink have been blistered indicating pretty high temp. on the esc.

More thoughts needed to make this thing work then. In the meantime, my BL mini inferno ST should be ready by this weekend. Hopefully, that will tide me over while I struggle with this.

Thanks guys for your support. Keep it coming while I ponder whether to spend more money to get this thing working again.

Regards,
Joe Ling