ONLY Info: MGM esc Brake Problems SOLVED !!!

[Mr. Constructor]

Here´s only the latest info on these braking down from full to mid problem occured on some mgm esc´s for the cars.
the Problem was solved, all new esc´s (mine too) are now with this software fix, the older ones could be send in and be updated for free (only sending in is your fee), please contact your dealers/importers if you´re in the us.
(about availability of this option)

you could send the esc back yourself too:

Adress:

MGM compro
Ing. G. Dvorský
Sv. Cecha 593
760 01 Zlín
Czech

Do include a small written task what you wanna make them do for ya and if possible a copy of your bill.

ALL new esc´s will not show this problem we all now have our super cheap high power 8th car esc, contact me if ya wanna have infos and wanna have the NEW esc´s.

[tcolesen]

Sounds great! Mr. Constructor- Do you know how quickly MGM will be able to service the controllers? If I were to send mine in, I wouldn't want to wait forever like Schulze. If I send it in, I would probably have Jamie do it.

[Mr. Constructor]

i was told around 2 weeks, but this may vary as the more esc´s they get the more time they might need ??!!??

Normally the time from sending it to receiving it is around 2-3 weeks here in europe, but america is another thing, i think it´ll take longer when send via jamie as the he will do the same thing than you would: pass it to the factory or his dealer/importer.

discuss that with him, to be shure, maybe he´s waiting little time to get more esc´s from various modelers and then have one big package send ???

i do not know, ask him, he will definately help ya in any way he could !!

[kufman]

This is good news. I will have to send mine in. One of the characters in the address for them shows up as a "?" Is this correct?

[Mr. Constructor]

it´s now ok, the american server cannot display the czech language so instead of an C with a ^ (but facing downward) on top, it made a ? out of it, i now corrected it to the C, the postage delivery should deliver it safely now.

thanks for the comment, i did not see that when watching it for controlling . . .
;-)

[kufman]

cool, thanks mr. constructor.

[OptimaMan]

Darn, and I sold mine for real cheap on ebay!!!!

[kufman]

Darn, and I sold mine for real cheap on ebay!!!!

I was a couple of days away from listing mine as well.

[Ventman]

Wonder if they'll do anythng to the one I hacked and slashed to shoehorn into my XXX-4, I ended up cutting the ends of the shrink off to get at the board and resoldered all the leads vertically, had to put the cap's on wires as well, all in all a good hack job, but would hate to think that this would ruin my chances of getting a real problem fixed.

[chilledoutuk]

Asuming they have a programming port on the controller i would think they would update the software on your controller and send it back to you.

[kufman]

Looking at my controller I think they have to cut the shrink wrap off anyway to fix the problem. I don't see a remotely accessable programming port.

[TheSteve]

This is great new for owners of the controller, its too bad more companies don't allow the end user to update software. At this point I believe Castle Creations is the only company who allows you to download ESC updates.

Just for interest the reason most companies don't allow it is because the firmware is the "key" to the controller, if the code was available for download it could be ripped off and used by another company. The processors most companies are using in brushless controllers are such that they can be programmed but the code cannot be "read" back out of the controller, only overwritten. As I mentioned above the exception to this rule is Castle Creations who uses a more modern/secure processor which has a secure bootloader area which cannot be read out of the processor and is required for proper ESC operation, then they also have the maincode which can be upgraded by the end user. The maincode alone is not enough to make a full functioning ESC, so they can make that available for download.

[Mr. Constructor]

that is a good point, but when did you (meaning all) updated your cell phone or digital camera or so ???
normally these function isn´t needed very much, only for the pc, but that´s a whole other case these things aren´t running without updates thanks to the "banana political" in this case, the product will get ready at the customer not the facitlity.

but if you ever crashed a good exp. mainboard due to a small interrupt during an update you´ll hate this process anytime.

it´s a medal with 2 sides (as with all parts ;-) ) there are negatives too, but if the people at cc made their homework well it shouldn´t be even used.
I do favore the option of only having the dealers a possibility to upgrade, as they normally are way more used to that then and it is easier for them to handle returning to factory issues if the esc was damaged at all.

but, ok we´ll see whether this feature is used or not, it is good to have the possibility, but most (hopefully, then they´ve made a good job) will not use it .

[chilledoutuk]

I understand the concerns of users being able to reprogram there controllers themselfs.
But do remember that if the controller has a properly setup programming port then even if the software is corrupt it should be possible to still flash the eeprom again.

The reason people scew motherboards up is that your computer needs the bios to boot the system and you need the bios to flash the bios if you corrupt your bios then you wont be able to boot and reflash your bios. gigabyte mobos come with dual bios for this reason.

[sugs]

I work in the telecommunications industry and have to deal with updating systems all the time, so doing this myself for a controller I may purchase in the future is a big plus. I wish Castle would hurry it up a bit as I can't stand the thought of having to send my controller all the way back to Europe to be fixed or updated. Turn around time is way too long.

[Rotary Rocket]

Starluck RC, do you have the new updated 120 controllers in yet?

Also in some of the posts it seems this problem might not be completely solved. Can the people who have the new version post their experience?

Thanks in advance.

[SpEEdyBL]

My 120 amp verson uses brake to achieve lower throttle. I don't notice this problem as a basher, but it's still there if you look for it. At least it coasts in neutral like it should. Icare said it was a "new version" but it's not computor programable. The computor programable ones should be out soon

[glassdoctor]

Does anyone have info on the PC programming link for the MGMs? I hope that it will allow the reverse to be disabled. Anyone know?

This is a bigger issue than the "rapid deleceration" thing. I want some drag brake but there isn't any built into the controller and you can't set it with the radio with the reverse, because then it can go into reverse whenever you are off throttle.

I have something to try that could work, but I'm waiting on a battery to charge....

[glassdoctor]

In the other MGM thread I posted some test run results, and had a motor problem with the 8L. Anyway, I now have a Hacker/Feigao 12L motor in the buggy. A quick test showed some impressive power and good speed. Not the top end of the 8L but still fast, somewhere in the 30's. I'll get a GPS test tomorrow.

The motor is a C50 Maxx (12s) can and a Feigao "L" rotor. So it should basicly be like a C50 12L. I think this will actually be a better all around motor than the 8L anyway... but I want to get some speed runs to compare them.

Question on the MGM... which "side" (top or bottom) would be best to have a fan blowing on? I assume the larger plate on the bottom (no label) is the best side to have the fan...

[Mr. Constructor]

depends on wich esc you have: 80 A version: it´s equal on wich side as it has on both sides the same number of smd fets, the 120A version has more fets on one side, i would prefer this side then.
Or best thing: try to have the esc mounted stand up, then a fan over it, so you´ll cool both surfaces at once !!
(a small L shaped alu piece might hold it easily in the up position.)

[glassdoctor]

I was thinking of doing that... getting air to both sides for really good cooling.

MrC, do you believe the PC programmer will allow to disable reverse?

[SpEEdyBL]

You wan't the air to get underneath the heatshrink. Or better yet, maybe you can make a an aluminum clamp that contacts both sides of the controller and at the same time have a fan blowing on the clamp.

[glassdoctor]

I ran my 1/8 buggy again tonight... 12 cells, MGM120, C5012L.

I need to find my temp gun to get some actual temps. I can get the controller pretty hot and it might be thermalling some. I have had it stop for a few seconds then keep running. I have probably been harder on the car than I would be while racing.

I can't help it.... the thing is fast! :) I have raced off road electric for years and this is still impressive.

Anyway, I hope the MGM120 can handle racing without a thermal problem. I would guess the hottest I have felt it is around 160-170 and the motor was just a bit hotter. I know, that's not good... and it's only like 70 and cloudy here.

[Mr. Constructor]

The brakes might not be disabled, the Programming versions now (from the planes) only include the same settings than possible via Radio too.
But i must say that i do not have the latest info on that, so posiible is everything . . . ;-))

If you could really touch your esc during a hot run, (even though it is for only a second) it is OK, mine do run on around 90° Celsius, sometimes hotter, they never failed (OK this was a testrun to test exactly this out, normally my esc´s are around 70° Celsius.

But first try to cool it down with a passive heatsink, not a fan, a fan if 100% needed to protect the esc will or might fail in a short period, the most fans out there are not well designed in the matter of taking jumps, hits, and any other harder impact during driving, they´re built for stand still purposes.

I did test the fan concept 2-3 years ago in my first 8th scale buggy, it doesn´t cool that much and failed often due to broken bearings inside the fan.

So i decided to choose esc and Motor and car combination with heatbuiltup in mind and then tried the pasive heatsinks, they´re working great !!

(try to look at the PC ones, maybe there is a way to use them ???
i do machine mine out of industrial cooling parts like big alu finned heatsinks, but as this is not available to all, the PC Cooler might be a good solution, then filed down where needed and that´s it .

By the way: if a fan is needed there is a anytime a holder included, so using a fan later isn´t that big problem.

[glassdoctor]

Thanks. I have some fans I can use. I have used a fan in my emaxx and never had any trouble with that one.

I do want to put a heat sink on the MGM120 though. It's runnin gway too hot and it's going into "thermal" mode after only 2-3 minutes hard racing. I ran one pack at the track today and it read 175* when it was overheating.

I checked the instructions and they confirm was I was experiencing.... when it overheats, it will keep running after a few seconds but reduces power to 60% as long as the temps are too high.

So far: The "half-throttle braking" and the lack of drag brake makes racing very difficult. This is unfortunate because it's a nice small controller with great smooth throttle respose and a solid BEC.

I don't know why things are running so hot with my setup. Any of you guys think I should be having trouble?

Kyosho 1/8 buggy
MGM120
C50 12L
11-12 cell GP3300
13/44 pinion/center gear

It runs like heII but it's hot as heII too :(

[tcolesen]

If I had to take a guess as to the temp, it would be because the motor is spinning so slowly on so few cells that it isn't anywhere near the efficiency range, and is pulling too many amps for the gearing that you have (with the amps replacing the voltage that it is lacking). I would imagine that even 12 cells on the 10L might cause the controller to heat up quite a bit. I think a 9L wit a 52t spur would be a better candidate.
I myself am running a 8L on 12 cells (soon to be 4s Lipo) geared at 16/64 (32p gears), and for the entire run, the motor and 9918 don't get any hotter than 145*. The F/R diffs to have a higher ratio than most, at 13/43. I will be gearing it at 13/52 with mod1 gears when I get it all set up, and will see how that does. I think a 9L would be a better choice, but I want to make the most out of my motor.

[glassdoctor]

Yours is geared a little lower than mine 13.2:1 vs. 11.2:1 but then I do have a 12L which should easily account for the difference in gear ratios compared the 8L. I think I have a 46T spur I can put in to gear a little lower.

Really, if an 8L on 12 cells runs well... switching to a 12L and bumping up a tooth or two shouldn't be all that much different. I would even think it should run cooler...

I don't know.... it just doesn't sound right. I goes against everyone's experiments with motors, like going form a basic 5300 to a 4200 and gearing up to compensate for the rpm difference, to get similar performance with similar or lower temps and better efficiency.

Actually I thought I should go with an even lower KV motor since it's difficult to gear much lower. There is a 10T pinion available so maybe I should just try that first.

P.S. after a couple runs with the 8L and 12L I and thinking about trying a smaller motor. Any suggestions?

[glassdoctor]

Hey, I need to get some video of the buggy and see how fast it looks on screen and see what you guys think. It's way faster than the video I shot in the snow before which was on 9 cells and no traction.

I know it's faster in person than I ever expected based on watching videos of other buggies.

They just look faster in real life. :0

[Rotary Rocket]

Glassdoctor, who has the 10T Mod 1 pinion? I know Jaime has been trying to get them for a long time, does he have them in stock now?

[NIC]

Hi glassdoctor,

You can try and use the Kyosho plastic 46T maingear if you have the standard metal one now. It will reduce rotating mass by 25 grams early in the drivetrain. Part number is IF148, and it´s cheap at around 6 Euro and will hold up well. It can make a pretty large differens if there is alot of acceleration and braking.

Try also to set the the timing to the softest setting, and gearing down if you think your car is to fast for your track could also help.

Maybe it´s your hybrid of Feigao/Hacker that´s not matching up right ?
If I run my Hacker 11L on just 6 cells and really do alot of acceleration and drive constantly and try to pull as much amps as possible the motor won`t even get warm. The car is a complete dog though on 6 cells as you can imagine. I tried a pack of 8 GP2200 from my touring car with an increase in topspeed and acceleration but no heat from the motor. When I drive with
12 GP3300 some "heat" build-up will accur but not hot at all. Then on 15 cells it will heat up to about 80 C when driving at our track.
Spinning a Hacker L motor at 30000 or below in a 8th scale buggy with standard 13T gearing shouldn´t heat up so much.

Hope I helped some.

NIC

[Mr. Constructor]

The 13/44 setup turned my alert, try a little bigger main gear, i do know kyosho has a 48 t spur for this car, try this one, the speed will be not that much less, but it´ll kill those very high heat temps.
have a look at your connections too, do use only high quality materials even when connecting the cells to each other !!!
a weak connector soldering point could cause that heat too, use only silver flux for soldering, it has no solder flux inside and has a relatively high amount of silver in it, so the connections are very excellent then.

[glassdoctor]

rcmonster.com shows a 10T on their site...

I'm not sure if the "frankenstein" motor is to blame. It really runs well and the 8L ran hot also so that won't fix it.

Anyone think running a 2000kv motor on just 10-12 cells is a bad thing?

The reason I have a 44T center gear is that I ordered the plastic kyosho gears and the 44 was the first one to get here. I have the 46T plastic somewhere...

Some chassis modifications will be needed to run much bigger than the stock 46, which I would rather not do. 46/10 would be geared really low at 15.2:1 final drive ratio. I don't think we should have to go lower than that.

Oh, the battery connections etc are good... I've been building my own race packs for 15 yrs now, and there aren't signs of a bad solder joint or anything.


MrC, I like the layout of your conversion and I'm thinking of trying a similar setup. Will you be willing to sell some of the parts individually?

Thanks for the help.

BTW, I think I also need to try a speed run with the 18t pinion just to see how fast this setup can go on 12 cells. I'm guessing 50+ easy before it thermals. ;)

[glassdoctor]

One last thing... my MGM120 doesn't have dual wires. Anyone else have one with single motor/batt wires?

[Mr. Constructor]

the newer ones are with 1x 4scare mm cable, mine was a pre-production unit.
This is better than having to solder 2 thick cables together like on my esc !!

anyway i could sell parts indiviually on my conversion kits, feel free to email me if ya like, but be warned, most parts could only beeing used with major chassis changes, so a full conversion might be easier at all.
But i could help ya out with normal drivetrain parts or anything like this too, we´ll have to diskuss that !!
(i do have a wide choice on such parts, i could look these up if needed, we´ll see what might fit best !!)

[SpEEdyBL]

Tell me the Final drive ratio, the tire diameter, the weight of the vehicle. Any binding in the transmission? See how long the wheels take to stop at full throttle in the air. What timing on the controller are you using? Try 5-10* timing, and be sure your not in boat mode.

[glassdoctor]

Well the ratio is currently 11.2:1 and I think the tire dia. is 4.5"

Oh... I GPS'd the car at 36mph with this setup and the batts weren't fresh off the charger so it might get a click higher if I tried again.

I have pages full of drive ratios and speed calculations, etc and I can crunch those #'s, I just haven't done it yet or check my old scribbles...

The drivetrain seems as free enough although it's a new car and the bearings may still loosen up a bit. Anyway there is not any noticable binding or drag.

The timing is set to automatic which MGM recomends. You think I should change that?

[tcolesen]

My 12s in my Rustler would always run hot on 3s Lipo. Jamie suggested I try 5* instead of the automatic timing with the MGM 120amp controller. I didn't really notice a difference, but you might.

[SpEEdyBL]

The instructions say not to use automatic timing for high inductance motors.

You might be over geared since you're only getting 68% of the motor's kv with 12 cells. Even if your car went 40mph on a full charge thats still only 76% of the max calculated speed. Are you sure your tires are 4.5"? That's almost as big as my masher 2k tires.

[tcolesen]

They are about 4.5". Remember, this is 1/8 scale ;)

[glassdoctor]

I only have a minute online here so all I can say now is it doesn't look overgeared by the way it screams :) but you could be right... back later...

I'm back for a sec :)

I ran it yesterday and tried to take it easy... ran for a couple minutes and talked to guys standing around the track... ran for a couple more... etc. I managed to dump the pack without thermalling but it was still to hot, imo.

I think I probably got at least 6-8 minutes from 3300 on a hard dry dirt track. Traction was ok in the groove but was easy on the car, not like running on tacky stuff or grass etc.

I'll try to think on the gearing/speed thing and get back on that... but I'm going to Chicago this weekend so I might be awol for a few days.