Thermal cutouts on my 500 3d

[billyd]

Hi guys I have an Orbit 25-8 motor with a 15 tooth pinion, and a Jazz 80 controller on my Logo 500 3d flybarless. I am running in governer mode at 70% flat throttle. I am not using the Jazz bec (have red wire pulled out of connector). I have the Jazz mounted outside the canopy (moved it out from under the canopy to get more air flow on it, did not help). It is getting very hot, and it seems like every other flight I am getting a sudden drop in RPM about halfway into the battery. I believe it is a thermal cutout. If I land, disconnect the battery wait a few minutes and reconnect it, I am able to fly again.

It doesn't happen every time either. What are your thoughts? I put a watt meter on it and only got a 40 amp peak. Why is the ESC getting so hot, not using the bec and only pulling half the rated amps???? Motor is warm, but not hot, a good tempertature.

Do I have a bad ESC? Should I install a heat sink on the ESC? If I do install a heat sink, which side of the Jazz should I attach it to? The label side or opposite? Should I remove the shrink wrap cover from the esc prior to applying the heat sink?

[LITHIUMSTATIC]

Flip over the Non label side out as this is the hot side that needs air. I know a guy that this fixed his.

If that doesn't work then cut away the shrink wrap on the NON label side and glue a heat sink on with thermal epoxy.

[billyd]

Flip over the Non label side out as this is the hot side that needs air. I know a guy that this fixed his.

If that doesn't work then cut away the shrink wrap on the NON label side and glue a heat sink on with thermal epoxy.


Many thanks Jeremy. Of course I put the label side out, lol. I had a 50/50 chance of getting it right and I blew it. I guess the folks at Kontronic don't want the publicity? Strange that they would put the label on the cold side! Unusual!

I will try it and I bet that will do the trick. With the non label (hot side) facing the frame I wasn't getting much cooling even outside the canopy!

[ozsteel]

See this thread....http://www.helifreak.com/showthread.php?t=66193

[billyd]

See this thread....http://www.helifreak.com/showthread.php?t=66193


Very informative, thanks for the link. I have to say that Kontronic ought to make it clear in their instructions that the label side should face the frame for proper cooling. Surprising they would omit this important fact since it is unusual to put the label on the cold side of the ESC. A non standard approach, and very strange, IMO. :confused:

[Big Fil]

Since flipping mine over I've yet to have a shutdown since and haven't had to install a heatsink. Last weekend it was 87 degrees and flew the snot out of it with no issues. I'll still probably ending up putting the heatsink on when it get's well into the 90s and 100s here in the summer but I want to see at what temps it acts up at again. Much hotter than 90 and i'm not flying much anyway cuz my brain starts to thermal sitting in the sun.

BTW, the manual does actually say to mount it label side down but it's a pretty obscure note that could easily get missed. I only found it when I needed some bathroom reading material.

[BruceW]

If flipping the ESC doesn't work for you then you might want to consider a 14T and bump up the governor to 80-85%. I run 15T on a 1100KV motor but yours is 1210KV - for the same pinion yours will run about 220 RPM faster. Going up 15% on the governor with a 14T should give you about the same headspeed as a 15T but with easier gearing.

Just a thought.

[billyd]

If flipping the ESC doesn't work for you then you might want to consider a 14T and bump up the governor to 80-85%. I run 15T on a 1100KV motor but yours is 1210KV - for the same pinion yours will run about 220 RPM faster. Going up 15% on the governor with a 14T should give you about the same headspeed as a 15T but with easier gearing.

Just a thought.


I have a 14t pinion on the shelf. I might try that if I continue to run into problems. I read somewhere here on the freak that the Jazz ESC should be run at 70% throttle for best governer performance. 85% might be too little overhead for the Jazz to maintain h.s. during hard maneuvers.

Frankly I was shocked that my watt meter said I pulled only 40 amps peak. That seems very low, especially since the esc is getting so hot. You would think that an 80 amp esc wouldn't even get very warm at 40 amps load. But then again I am getting around 8 minutes flight time (sport flight and a little 3d) at 80% of my battery which works out to a nominal load of around 30 amps, so I guess it's right. Why does the Jazz get so hot????

[billyd]

Since flipping mine over I've yet to have a shutdown since and haven't had to install a heatsink. Last weekend it was 87 degrees and flew the snot out of it with no issues. I'll still probably ending up putting the heatsink on when it get's well into the 90s and 100s here in the summer but I want to see at what temps it acts up at again. Much hotter than 90 and i'm not flying much anyway cuz my brain starts to thermal sitting in the sun.

BTW, the manual does actually say to mount it label side down but it's a pretty obscure note that could easily get missed. I only found it when I needed some bathroom reading material.


Oops I guessed I missed it :o sorry Kontronic.... But you could take it out of the fine print.

[BruceW]

When I ran the Hacker A40-10L-8 with a 16T and Jazz at 70% everything seemed to run very hot. Tached it at 2300+ HS, switched to 15T, went to 86% and everything runs cooler (motor, ESC, and battery) and still have the same HS. Remember, if you gear the motor down you should not need as much head room on the governor to maintain headspeed.

If you have a 14T, its worth a try for your own experimentation. Also, since you are running flybarless you won't need as much HS for optimal power so 80% might be even better.

If you want to check your own choices, I have a Windows head speed calculator with sliders to allow all parameters to be tweaked. I found 94% efficiency to be the rating on my motor - its just a calibrating fudge factor anyway.

Here it is... http://www.helifreak.com/showthread.php?t=55471

[billyd]

When I ran the Hacker A40-10L-8 with a 16T and Jazz at 70% everything seemed to run very hot. Tached it at 2300+ HS, switched to 15T, went to 86% and everything runs cooler (motor, ESC, and battery) and still have the same HS. Remember, if you gear the motor down you should not need as much head room on the governor to maintain headspeed.

If you have a 14T, its worth a try for your own experimentation. Also, since you are running flybarless you won't need as much HS for optimal power so 80% might be even better.

If you want to check your own choices, I have a Windows head speed calculator with sliders to allow all parameters to be tweaked. I found 94% efficiency to be the rating on my motor - its just a calibrating fudge factor anyway.

Here it is... http://www.helifreak.com/showthread.php?t=55471


I wish I could find the thread for the Jazz governer setup. However someone who was introduced as an expert on the controller insisted that the throttle gain should be set at 70% for governer mode on Jazz controllers.

Running closer to 100% would naturally reduce temperatures in the ESC since they run coolest at max rpms. I guess the attenuation of lower throttle gains generates excess heat in the ESC. As long as you aren't dropping HS in extreme maneuvers, the higher throttle gains are a good idea. It's difficult to know without a data logger if your rpms are varying through the flight. If flipping the ESC label side in to the frame does not resolve the thermal cutouts I will switch to the smaller pinion and adjust the throttle curve accordingly.

[Big Fil]

Remember that the Jazz is getting hot the way you have it mounted because it's basically trapping the heat and doesn't have a way to bleed it off. Also on the Logo the location is right next to the motor and the heat gets trapped in the canopy. Unlike say a Trex 600E where most have the ESC mounted on the side where it is completely exposed to the outside air.

[billyd]

Hi Big Fil. I moved the ESC out from under the canopy and have it mounted on the side with the label side in. I have yet to fly it like this, just did it tonight. I think the ESC under the canopy is a terrible idea regardless. I never liked it when I first built the heli, but figured it would be ok, until I saw how hot the esc was getting.

Also the logo canopies are real heat traps with their wraparound design. I think I will be adding some vents for the motor as well.

[flymustangs]

I believe this happened to me yesterday. I was doing some hovering and a little bit of FF. At about 4 minutes into the flight I noticed a power reduction. I instictively hit throttle hold, but after thinking back I believe I still had some power. The ESC was pretty warm, but I didn't have my thermometer so I'm not sure how warm. It didn't seem any warmer than other flights. The motor and battery were fine as was the voltage on each cell of the battery. My ESC is mounted label side up. I will change that. I'm running a 14T pinion at 65%. I'm sure that's contributing to the heat, but I believe you can go as low as 56% on the Kontronic. I'm getting about 2200rpm according to the data logger. The data logger also showed a max amps of 26. That was the first auto I've done with the Logo and it came out just fine.

[Finless]

I HAD to put a heatsink on mine and that helped a lot but because this is a double layer board ESC, the heat sink is only helping one board worth of MOSFETs.

Then last weekend it was a hot day 95F, and I am running the 1100KV motor and 16T pinion. It thermaled on me and went into a low RPM mode. I am going to the 15T pinion now and I hope then helps the temps.

Bob

[billyd]

I HAD to put a heatsink on mine and that helped a lot but because this is a double layer board ESC, the heat sink is only helping one board worth of MOSFETs.

Then last weekend it was a hot day 95F, and I am running the 1100KV motor and 16T pinion. It thermaled on me and went into a low RPM mode. I am going to the 15T pinion now and I hope then helps the temps.

Bob

I think I will order a heat sink. Ya know..... Kontronic should do something about this problem with the Jazz 80. I am nowhere near 80 amps, running at less than half that amount nominal with peaks in the 40 ampere range and not using the BEC. Heat should not be a problem!!! I think this ESC is grossly underdesigned for an 80 amp continuous load. I don't even think it could hack an 80 amp peak. I like the ESC in every respect except for it's lack of heat management. Obviously this esc needs heatsinks on both boards from the factory, like the CC85HV has. KInd of ticked off about this.....:mad:

[LITHIUMSTATIC]

I really don't think you need to heat sink mod it if your running the right pinion and have the non label side facing out. To many people are running it without problems. Also, I've seen a triangular hole cut in the canopy just above the "windshield" area. This should solve any heating issues on the Jazz 80.

[billyd]

I really don't think you need to heat sink mod it if your running the right pinion and have the non label side facing out. To many people are running it without problems. Also, I've seen a triangular hole cut in the canopy just above the "windshield" area. This should solve any heating issues on the Jazz 80.


I'm pulling 30 amps nominal with a 40 to 45 amp peak. How can that be a pinion problem with an 80 amp ESC?

[LITHIUMSTATIC]

Do you have an Eagle tree graphs or something we can see?

Honestly try what I said and see if it works. You shouldn't have any problems if you do the suggestions I listed. If you do these suggestions and it still thermals then I'd say your is defective.

[billyd]

I have a "watts up" meter that I put on new setups. Anyway the "outside canopy and label in" mounting flew fine today with 87 degree ambient. But the esc is really hot at the end of a flight. My guess is the ESC will cut out on a really hot day.

I don't think I have a defective Jazz 80, I think these units run really hot for whatever the reason. Look around the forums and alot of them have similar threads to this one. This is a design issue IMO. Kontronic needs to put heatsinks on these units, I shouldn't have to complete the design for them. I know I am running around 30 amps nominal because I have a 5000 mah battery that I am putting 4000 mah back in after an 8 minute flight. Sure if I increase the throttle gain the esc will cool down, or even if I run a different pinion. But the point is, there is no reason in the world the Jazz 80 should not be able to handle my current setup. Is it an 80 amp ESC or isn't it? 70% throttle on governer is not an unusual setup, nor is a 30 amp nominal draw.

[LITHIUMSTATIC]

Fly it like it is and when you get time heat sink mod it and should be good to go.:thumbup:

[Mercuriell]

I wonder if it might be soemthing to do with timing and the Orbit motor - I'm running two 55-10-32 on the L500 and 600 on 6s and 10s - the 6s is heatsinked but both get barely warm after flight let alone hot on Z50 and Hacker 40

[Eyon]

timing for a plet should be between 20-25 degrees, 22 always works well no matter what you run it on