did you try to reprogram it? I have seen the esc do some strange things cause it lost memory or something.

Yeah every time you plug it in you can choose to program the endpoints and I've done it over and over. Now it won't work in another truck either and it's acting strange like the throttle or brake wouldn't work, then they started working but reverse just barely moves at cog speed. I think it has to go back.

sounds like you found the problem. Just have to get it fixed now.

I just emailed Mtroniks so we'll see what they say.

I've had that happen to my Mtroniks Truck before. After reprogramming the throttle and brake endpoints, it would always work again.

This hobby is supposed to be fun, right? I went to run my 1/8 buggy today and put in the new FM radio I was using on the MT. I get there and guess what...it starts glitching. Son of a ________!. I say to myself, "This can't be the problem. I tried the other PCM radio in it and it glitched before." So I get home, switch to the PCM radio in the MT and guess what, IT DOESN't GLITCH. Ugh, great so the problem is my brand new FM radio. I tried another receiver so it's not that. I think I'm going to try a different frequency set of crystals. If that doesn't fix it then I'm in trouble.

Cart: At least I know I'm not alone. It must be a software thing then.

Just got back from a top speed run. GPS says 46mph with 52/15 gearing and Dirt Hawgs. I also only got about 7 min of runtime. Does that sound right for a 6L? It is overgeared though so that might have something to do with it. Got some high temps also. It's about 90 out right now and the motor got to ~140, ESC ~ 145 and batteries ~160 in some places :026: . I think I'm gonna need fans. Again it could be because it was overgeared also.



*edit* Hmm. Out of curiosity I checked the voltage on the pack and it was at 10.25. Seems a bit high for a dead 8 cell pack. So I hook it up again and it's still fine. Does the Mtroniks have a thermal throttling where it will cut the voltage down or something and not just stop? Would it do it at only ~145 deg?

*edit 2* Or not....I just charged the pack and it took 3800 mah.

Those temps are fine for the motor and esc. Over 165 is when you should start to worry. For the batteries, yeah, that's a little hot. Do you have good solder joints and connections? Who knows, maybe any ni-mh batteries will heat up on such an amp hungry motor.

I'm not sure why the batteries get so hot. I thought the 6L was mild as far as amp draw ~69A? It's only the third pack I've assembled but I've been soldering forever so the joints should be all right. Oh well.

15 tooth, that's way to big. I use a 9 tooth on my 540 9s and I'm sure you would benefit from a smaller pinion also.

I know it's too big for the dirt hawgs, I really bought it to use with the Road Rages. The 13t seems better but I haven't gotten temps for it yet.

Hmm. I use 52/14 gearing with big ole M2K's, and I haven't thermalled anything...yet. I haven't run in the hot summer sun yet, though. I usually do it early in the morning. I still need to go to the lhs to pick up a few replacement parts to get it running again.

Hmm that's odd Cart. Maybe because you have a 540 and mine is a 380? 9t seems kindof low combat. I'll see how the 13 does but it already has enough torque with that so I'd hate to sacrifice the speed by going even lower. Even with the 15t it has a decent amount, enough to spin all 4 tires for a while.

Like I said you motor and esc temps are fine. You could even gear up get higher speeds. It's your batteries that you need to worry about. Buying another motor wont solve the problem off maintaining top speeds and reducing battery temperatures.

I wasn't going to switch motors, I was just wondering. I don't really know what to do about the batteries. Cart's thread on emolis got me thinking so I may try them anyway, or LiPo, but probably not for a while.

Is anyone else this unlucky, or is it just me who can barely get through a pack without breaking something?

http://img.photobucket.com/albums/v2...2686Medium.jpg


Ran it with the Road Rages and geared 52/15.

ESC ~150
Motor ~168 great
Batteries ~ 140

Maybe it's because the high traction on-road causes so much amp draw? I don't know. Every time I have a little "accident" also, the right battery pack smashes into the pinion, which is my fault by design. Still, my patience grows thin with you Mr. Brushless MT.

Ouch! You should get some GPM aluminum c-hubs and uprights to replace the broken plastic c-hub. I got some, and they've held up well so far.

Don't give up yet!

Ouch thats pritty crazy man, i know that pinions are pritty pricy but you might have to get new pinions and try out different combations. And then see how the temps are.

Just to verify my rs4 Mt here, is the gearing fine on 51/13? on a brushed 18t motor?

I keep looking at the aluminum but I keep telling myself that if I'm going to buy the knuckle and c-hub, I might as well get the arms, then I might as well get the arm mount and then I can't just have it in the front so I need the rears. And that adds up to $200 or so. Then I go on tower and see the knuckles and hubs for $4.70 or whatever and I don't know.

When I get it fixed I'm going to try the 52/13 with the Road Rages and see what happens. It's seems really low to me but at least then I'd know if it's over or undergeared. It could be that it's undergeared right now and that plus the high traction is getting it hot? The cooler temps from the first run with the Dirt Hawgs were in the dirt/grass but geared pretty high 52/15, so I'm unsure.

Hmm also now that I think about it, this run was with the body on, so maybe that has a lot to do with it.

Well, I got some aluminum knuckles and the hub carriers, so they should hold up nicely. Got some more temps also. Just playing around in my yard with bursts of full throttle and a crappy fan on the motor:

Ambient: 90

After 6 min of running:

ESC: 160
Motor: 150
Batteries: 140



After 11 min of running:

ESC: 185 (eek...I think it thermalled so that's when I temped it and quit)
Motor: 167 (eek again)
Batteries: 145 (ok)

I need some really decent fans for the ESC and motor if I'm going to run this thing when it's 90 out. Unless it's gearing, but it's hard to test gearing at $12 a pinion.

Those temps can definitely be attributed to gearing. Using a smaller pinion would do the trick, but it's understandable that you'd rather save $12 if you can help it.

I'm going to try 52/13 with the dirt hawgs tomorrow and see how bad it is. Then if that doesn't work, 52/13 with the road rages. The motor got to 168 last time with 52/15 and the road rages, which are much smaller than the dirt hawgs, which is why I wonder. That was mostly full throttle on pavement though so we'll see.

So I tried 52/13 with the Road Rages:

~90 ambient

After 6 min of running:

ESC: 140
Motor: 145
Batteries: 130


After 11 min of running:

ESC: 165
Motor: 167
Batteries: 137


It can't possibly need to be geared any lower can it? The ESC is doing better but the motor is still struggling. I don't know what the next step is except some good fans. Maybe it's just too hot out? :confused:

Well All three temps are hi. I dont know about final drive on the truck. The temps are higher than I would like to run them. If going down helped. Maybe try a little lower to see. What you have is good for a speed run or something.

Final drive is 2.92, if that helps. They are a lot higher than I would like to run also. I can't even get a full pack in because I'm afraid of killing the motor.

Well, I spoke too soon about my system not overheating. Yesterday, I pushed my system over its limits by driving at high speed in grass during 100F weather. The controller thermalled after about 5 minutes. I don't have a temp. gun, but the controller was too hot to touch continuously, and the motor was almost as hot, but I could keep my finger on it. The emoli cells were barely warm, though. I do love those cells! :) In case you forgot, I'm geared 52/15 with M2K's.

The motor temps are fine IMO as long as you don't exceed 170. Same goes for the esc.

Thanks for the info Cart.

Speedy, I'm just afraid of 170 because that's where my Novak 5800 died (178 it hit I believe). I know technically the ESC is fine unless it's thermalling, I just don't like it that hot. Like I said, maybe I'll try other gearing but most likely I'll get the fans just to keep it in check when it's this hot out.

I don't know if the fact that there is no slipper/diff in the middle has anything to do with it? Maybe it's putting a lot of strain on the motor when the power has no place to go?

I'm technically not running a slipper either, because I've got it locked down tight. If I loosen it just a little bit, the torque of the motor will loosen it up completely within a few minutes.

Hmm, I was hoping it would take some strain off the drive train when accelerating and braking.

Now you have me thinking. Do I want to even bother ordering the slipper assembly? Or no since I'd most likely have to lock it anyway?

You may not have to lock it. My 540c-9L motor has a lot more torque than your 380c-6L, so you might not have my problem. There's no way to know for sure unless you try it.

Yeah I will probably just order it since I chewed up this spur pretty badly somehow.