Having some heat issues.....

[10kman]

Running a Castle 1518 @ 1800 k/v, MMM ESC, and both Turnigy 4s and 5s lipos.

Nothing obvious looks to be wrong, no binding issues anywhere, lipos are balanced, no sticks stuck anywhere, etc.

Tried originally running 18/49 gearing (brushless MGT 8.0 vehicle), on 4s, and in grass, motor would get upwards of 155-160 after a pack (5000mah).

Didn't like the temps, so started doing some math, and the truck was geared for about 33 MPH with that ratio, so I upped it to a 20, and a 22t. Both yielded same results, heat.

Tried a 4s pack again today, using a 22t pinion, in a parking lot. Drove around, checked every 5 minutes or so, and it was doing the same, getting hot. I finished up the pack, and it was again nearing 160.

Read some more, figured the relatively low k/v would like more juice. Tried a 5s lipo with 22t pinion again, but in grass, and it got hot again, almost 160.

Dropped back to an 18t pinion, on 5s, and same deal.

I'm worried because it's not really stopping at a mid-150's temp, it's climbing the longer I go. I'm driving normal, on and off, jumping here and there, rolling it over, going to get it, so it's not a race with constant throttle, no speed running, I rarely even get to full throttle anyway, the truck flips onto the lid in no time.

On 22/49 gearing, my final drive is 12.52413:1.
On 18:49 gearing, my final drive is 15.30726:1.

4s lipo puts the motor at 26640 rpm.
5s lipo puts the motor at 33300 rpm.

Max RPM on the can says 60,000.

ESC is rarely at 130 with either setup, and the batteries seem to end up about 10 degrees above air temp. So no issues there.

Am I just not putting enough voltage into this thing to get it to a better point of efficiency, is something wrong, am I driving too hard in spite of my gearing options? I really don't think it's the driving style, I'm really not doing anything extreme here.

Thanks for some ideas. For comparison, my first e-MGT I used a Neu 1515 1/Y @ 2200 k/v, and was using 18/52 gearing and 15/52 gearing off and on, and didn't ever have an issue. Same temp gun too, 4s lipo.

I have a picture attached of the mounting, I was thinking it's not getting any airflow. Windshield is cut out on the body too. Do I need to fan it?

10k

[suicideneil]

Interesting, I have seen a few guys who had motors that seemed to run quite warm no matter what, it may just be something you can't control ( I don't wanna say the motor is a lemon as such ). 160 isn't the end of th world though, if you were pushing 180 every time then it would be more of a concern.

Have you looked at punch control and timing options? Stock ( normal ) timing is a couple notches up from the minimum zero option, so ti may be worth lowering that and seeing if it helps, maybe raise punch control too- make certain the drag brake is disabled.

[10kman]

I'm looking right now.

Drag brake is disabled.

Punch control is disabled, but I was meaning to set that to 20-30%, I'm getting sick of it lifting on me all the time.

Start control is set to Low, out of Low, Medium, and High being an option.

Timing was set to Normal.

I just set punch control to 30%, which I will try tomorrow.

I also set timing to Lowest, 0%.

My gearing, to me, doesn't seem aggressive, even on the 22t pinion and 5s. The motor is a beast, it's throwing the truck around like a toy, it should be laughing at me.

I did find a fan, but I'm not going to do anything with that until I'm done fiddling.

Thanks for the ideas, I was really thinking that no matter what, my setup was going to be fine. Like I said, it's a really strong motor, very happy with it.

[10kman]

Got an early morning run in. Ran 5s and 18/49 gearing.

By the end of the pack, with the changes, I was hovering 150-160. It didn't really seem to help a bunch.

I did have a mild tumble and the motor mount shifted on me, the mesh seemed tighter so that could be a variable, more work being done. I will remesh and check again, but then it will be warmer, so yet another variable.

Also 30 percent punch control didn't do a whole lot. I may go to 50 and see how she does.

Stay tuned.

[brian015]

Originally Posted by 10kman

I have a picture attached of the mounting, I was thinking it's not getting any airflow. Windshield is cut out on the body too. Do I need to fan it?

10k

From your picture, I'd be concerned about the airflow - that plexiglass(?) plate looks like it would shield the motor from a good bit of the airflow. Did you use the same setup in your first e-MGT that didn't have heat issues?

[10kman]

It's lexan, but yeah, plastic over the top of the motor.

I didn't have the battery up top before, I had it on the side. I can do it in front of the tranny too, I can always try that to get more flow.

[10kman]

Changes -

Took off top plate of lexan and moved the battery to the front of the tranny. Also put punch control to 50%.

Ran in a parking lot, the other area I've been testing at had a lot of people traffic so decided against it, even though it would have helped stay consistent.

5s pack ran first, gearing the same throughout (18/49). Drove pretty hard for the parking lot, lots of back and forth running, harder than normal bashing I think. Temp climbed to about 152 by the end of the 5s pack, so it wasn't too bad.

Let it cool down to about 113, then put in a 4s pack, and it did about the same for temps. Was running this pack hard, it felt slow so was throttle heavy for a lot of the time.

I won't change gearing, and try to get some grass time tomorrow and see how it does.

I think the plastic removal helped somewhat, I'd like more of a buffer though for temps, but at least I'm not in the danger zone.

I did write to castle to see what the danger zone actually is for that motor, this could all be for nothing.

Thoughts? Temps were warmer today, and more humid, upper 80's, breezy.

[brian015]

I was running my Muggy earlier in the summer a lot on 4s and 5s geared for 40-45mph with the 1518 and was normally in the 130's at the end of a pack (a couple of times in the 140's). The Muggy weighs 12 lbs. rtr - if your MGT is heavier than that, it might account for your higher temps.

[suicideneil]

I believe Castle themselves rate the magnets for 200*F, though we tend to say 180*F to make sure the motor isn't being ran right upto the failure point, allowing a buffer as such.

If it's hitting 150*F at the end of the run & you aren't babying it, then I reckon you're good to go really.

[10kman]

I ran again this morning in the grass, was doing a lot of back and forth type of stuff, it peaked out at 160 on a 5s pack.

I took a couple breaks in there, but I think I'm going to leave this alone and hope for the best. The truck is heavy, more than a buggy, I'm guessing 14-15 pounds ready to go. I'm curious if someone has the same motor in a flux or lst, something that is pretty heavy, and how their temps compare.

[crazyjr]

If I'm correct, The latest gen motors , Including the 1518, 20 and the 1717, were rated at 300* not 200. If true, you are still well in the safe zone, but a bit warm for my taste. Have you tried the torque control over the punch? Did wonders for my MM/4600 combo, easily dropped temps about 20*

thats the magnet, when the housing is 200 i believe the magnet to be a lot hotter.

[10kman]

I haven't touched torque control, any pointers before I fiddle and read up on it?

From what I quickly read, I'm going to try 7 in the setting to see how it feels.

[10kman]

Torque control tested on 5. Ran it hard in a grassy area again, chased a few squirrels trying to get away with some non-standard squirrel food (bagel), and temps still touched 160.

Torque control dialed down that power quite a bit, it wouldn't wheelie unless I stabbed full throttle. Just still getting toasty to me.

This was all on 5s, 18/49 gearing.

[crazyjr]

Wasn't sure on how to temp properly sounds right. Here is my post on how to access the torque control, Bruce 750I in post 4 gives the best way to do the motor test to acess the torque control

http://rc-monster.com/forum/showthread.php?t=30393

have not put a tempgun on it but it lowered my 4600 motors temps by 20* easily