Medusa 36-60-2000 Problem *HELP*

[fastbaja5b]

Hey guys, I usually run a Jammin X1CR with a 4s Lipo and a Medusa 36-60-2000 geared 16/48. I have been running it with an LRP heatsink as pictured below and never had the temps over 129.

I ran it today without the heatsink (which was on my bench fixing a wire) and the temps got to 160 and still climbing, on a Medusa motor this greatly concerns me, as soon as it hit 160 I turned it off..... not risking it.

Should the heatsink make THAT much difference, does this mean I can't run this gearing obviously without the heatsink and if not what gearing should I be on? It's the classic batteries / ESC cool, motor warm-hot, but I was also told to gear for 35-40mph, this comes out at 40.82, I am only running badland tyres so they should be fine and my gear mesh is spot on.

Could it be changing from the MMM to the Hobbywing ESC on this? Is the Hobbywing speedy simply not going to like a 4 pole motor? Are my ESC settings wrong?

Need some help on this, my next thought is to put the Heatsink back on and try again with the HW, but I wouldn't have thought a Medusa would get this hot even without a heatsink.

so... HELP!

[fastbaja5b]

noone?

[glassdoctor]

A drop of 20 degrees or more, I think is common when running a fan on the motor. Is it possible that it was maxing out at 160? How long did it take to get there?

160 is getting warmer than I like, but it's not enough to do any damage... and I have seen many setups that tend to run around that temp range.

[suicideneil]

Interesting..

The timing on the hobbywing esc could be higher than you had it on the MMM, that would certainly make the motor run hotter, but a different esc wouldnt make the motor run hotter, all thnings being equal (if anything the esc would run hotter). I would look at the timing/ start power/ punch or switching frequencies on the esc, assuming those are adjustable. Gearing up would be the next logical thing to try after that to see if it makes a difference- or gear down even, try everything...

[fastbaja5b]

I noted the start power was on 5 on the Hobbywing, I usually have it at lowest on the MMM so have adjusted it to that level, timing I always put a 4 pole motor at 15 degrees and a 2 pole at zero.

I have also turned off drag brakes as I have it on the MMM

would these have been responsible for such a spike in heat?

[fastbaja5b]

ok dropped the start power to softest and the timing to 11.25, 10 minute run no heatsink got to 150 so that helped. was around 85-90 outside and I was doing full throttle runs, hard brake, turn, then return.

Given that, are my temps reasonable?

[BL_RV0]

Yes, those are good temps.