My Jazz went into Thermal Today

[Mathias]

Hi!

Was out flying my Logo 500 3D flybar today. I had set my timer to 3 min (breaking in new pack) and was mainly dealing with gyro gain settings. The last minute I started doing pitch pumping, and about 40 sec later the Logo suddenly went down in headspeed.

If I held my fingers on the Jazz for more than 4 sec, I would burn them. The motor seemed pretty cool.

As I stated in a different thread a while ago, I changed to the 14T/85% to get lower temps/longer flight times. I have now switched back to the 15T again due to performance wise...

So my question is: what should I do to make things run cooler?

My setup:

Jazz 80-6-18
Plettenberg Orbit 25-08HE 1210kV w/15T Pinion @ 70%
FlightPower EV30 6S 4500mAh
RotorTech 560mm and original flybar


Thanks,

[BruceW]

I think you just answered your own question. Either go back to the 14T or add a heat sink. Your worrying too much about what others say is an optimal % for your TC. Just fly with what seems right to you. I'm flying hard 3D at 86% (2350 HS) and get no bogging with everything running cool (120F) so I don't believe in this 70% optimal rule that has been floating around. If you gear down, your motor works less and you won't need as much headroom for the governor to keep the head speed up.

[LJS]

Hi Mathias,

What rpm are you running. Do you have a heatsink on it yet?

I run a 15 tooth as well. But I'm running an 1100 kv Z30 at 2100 rpm at 74% governed. Plus my routine is not too strenuous -- only a full pitch inverted climbout and tictocs to heat it up.

I think you're going to have to put a heatsink on it. I know there are existing threads on that topic. Good luck to you.

Keep 'em flying.:YeaBaby:
LJS

[Mathias]

I think you just answered your own question. Either go back to the 14T or add a heat sink. Your worrying too much about what others say is an optimal % for your TC. Just fly with what seems right to you. I'm flying hard 3D at 86% (2350 HS) and get no bogging with everything running cool (120F) so I don't believe in this 70% optimal rule that has been floating around. If you gear down, your motor works less and you won't need as much headroom for the governor to keep the head speed up.Yeah, that's possible true...

With the 14T I got around 2300-2320RPM @ 85%. If I then go with a EVO25 (now running EVO30), I probably need to ramp it up to about 90% to get 2350RPM. For my liking that's a bit to high... Or what?

The heat sink mod might be a good thing to do... Is it enough to just use a cable tie to add the heat sink on top of the ESC, or do you need to cut the heat shrink and use thermal conductivity epoxy to attach it?


Thanks,

[Big Fil]

You need to cut the heatshrink and thermal epoxy the heatsink to the metal plate in the ESC for it to work as intended. Just one questions though? Do you have your label facing out? If so flip that thing around so that the non-label side is mounted up. The Jazz cools itself much better in this orientation. Funny thing is they mention it in the manual but good luck finding it. If you continue to thermal then for sure add the heatsink.

Now we just need to figure out why Kontronik hasn't figure this all out yet.

[BruceW]

Yeah, that's possible true...

With the 14T I got around 2300-2320RPM @ 85%. If I then go with a EVO25 (now running EVO30), I probably need to ramp it up to about 90% to get 2350RPM. For my liking that's a bit to high... Or what?


I honestly do not think you will notice any drop in head speed if you go to a EVO25 - no need to change the TC. My EVOlite 5350 is rated at 17C and it holds the head speed quite well and is only about 110F at the end of the flight.

Are you doing full pitchpumping maneuvers like tic-tocs, rainbows, or other full stop moves? If not then you have no reason to worry about the governor efficiency. If it comes down cool and your happy with how all the other components are operating then it is working well.

Through personal testing and tweaking I have found that many of the statements floating around the forum about how the Jazz operates are not accurate (not trying to bad mouth anybody). It is very simple in how it operates and it does not remember the settings between flights except for the throttle range that was programmed in when going to mode 1 and then mode 4. It adapts to the cell count and load each time it boots up and stabilizes after the spoolup. There is no need to go back to mode 1 and then mode 4 if you change the pinion. I think the previous versions of the Kontronik ESC needed reprogramming but not the Jazz.


The heat sink mod might be a good thing to do... Is it enough to just use a cable tie to add the heat sink on top of the ESC, or do you need to cut the heat shrink and use thermal conductivity epoxy to attach it?

Thanks,

As Big Fil mentioned, you'll want to cut a rectangular hole in the heat shrink, apply some thermal epoxy (like ArticSilver) and it will be permanent - no need for a cable tie except to hold the whole unit to the frame. I used a heat sink from an old video card and then cut it down to size.

Here is a link to my heat sink mod.
http://www.helifreak.com/attachment.php?attachmentid=48802&d=1211441056

[th3tick]

Here's mine ;)

[Mathias]

Do you guys know if regular epoxy would work? I have some Araldite hanging around, but I'm not sure if it'll conduct heat...

I'm not sure where to get thermal conductivity epoxy here in Norway...

Also, when I first ordered the components for my Logo, I added a heat sink just in case. - So I do have the heat sink. ;) it looks like it'll be a perfect match on the Jazz.



Thanks,

[Mathias]

Just did some researching on epoxy that conduct temperatures here in Norway and I'm able to get Arctic Silver.

Also, I do have the label on the Jazz facing out.

[Jaso]

The heatsink has to be on the oppisite side to the label .
That is where the plate is that is on the fets that you want to take the heat away from .
I'm about to put a heat sink on my Jazz 55 , just waiting for the artic silver epoxy to turn up in the post .

Jason.

[buster1]

Is the heatsink really necessary - I am running, Z30 motor, 15T pinion with the Jazz controller and Evolite 6S5350 and everything runs cool after 5 minutes of decent 3D,
What do you think - should I just put one on for extra precaution?

[Flybar-less]

I could only run 2-3 minutes, even with a thermal epoxied 6 to 1 heatsink. Yes it is neccesary in warm to hot weather.

[itsparks]

You could put a small heatsink on like we all do, then us a laptop cpu fan or a 1"x 1" fan i have a few to donate if any one needs one, then strap a resistor or voltage drop dioed onto it and wola you got a cooler esc :P

[Mathias]

Oh! Sorry guys... Was tired last night - I have the label facing down.

I ordered Arctic Silver 5 last night. It'll be here in very few days.

I'm still a bit undecided on what gearing to run. Should run the 14T or keep the 15T on? I'm going to install a heat sink either way...

Just want to have everything clear before installing the heat sink.

1. Cut the heat shrink on the ESC to allow the heat sink to have enough space.

2. Add epoxy and put the heat sink on and let it dry.

3. Ready to go?


I appreciate inputs.


Thanks,

[billyd]

I think a big part of the problem is the Jazz 80 itself. People are having thermals with lots of different setups.

I love the esc, but frankly it runs way too hot. I have tried my exact setup with a CC 85 HV and it runs cool to the touch. Orbit 25-8 15t

Kontronic should have factory heatsinks on both boards. We're really only cooling one board by putting on a heat sink after the fact. Frankly, for the amount of money they charge for the Jazz, they really need to address this issue.

I wouldn't buy the Jazz 80 again. Frankly I would probably go with a CC and deal with the governer headaches, which never really was a big deal to me. I like to tinker.

[Mathias]

Oh! Sorry guys... Was tired last night - I have the label facing down.

I ordered Arctic Silver 5 last night. It'll be here in very few days.

I'm still a bit undecided on what gearing to run. Should run the 14T or keep the 15T on? I'm going to install a heat sink either way...

Just want to have everything clear before installing the heat sink.

1. Cut the heat shrink on the ESC to allow the heat sink to have enough space.

2. Add epoxy and put the heat sink on and let it dry.

3. Ready to go?


I appreciate inputs.


Thanks,Anyone?

I got the Artic Silver 5 in my mail today. I hope to finish this mod, so I can fly at our fun fly this weekend.

Another question... Is there any kind of special techniques that are used to spread the Artic Silver 5?


Thanks,

[Mathias]

I'm flying hard 3D at 86% (2350 HS) and get no bogging with everything running cool (120F)

Are you doing full pitchpumping maneuvers like tic-tocs, rainbows, or other full stop moves? If not then you have no reason to worry about the governor efficiency. If it comes down cool and your happy with how all the other components are operating then it is working well.Bruce, if you are doing hard 3D at 86%, why don't you concern about the governor efficiency? I mean, you say I need that I don't need to worry about the governor efficiency at 85% if I'm not doing pitchpumping maneuvers like "tic-tocs, rainbows, or other full stop moves"?

I take it since you are flying hard 3D, you are doing this kind of maneuvers? And I've seen a video of you flying your 500 at hard 3D, and I don't remember I could see a HS drop...


Thanks,

[BruceW]

I guess what I'm trying to say is the governor seems to work just fine for me at 86% and keeps the head speed up with no bogging (or not enough that bothers me). Others have been saying the governor is most efficient at 70% so I've always wondered if I'm doing it wrong or not. So far with my own experimentation and tweaking between running a 16T and 15T I've found that the 15T (on the Hacker A40-10L 8 - 1100KV ) makes everything run much cooler and probably runs the motor in a more efficient range with higher RPM. Since I've been happy with the way it has been running I did not want to switch back to 16T just to experiment.

Maybe the Jazz is more efficient at 70% for some but I think finding the optimal RPM range for the motor is more important and will become a bigger factor in overall efficiency. Each motor has an optimal RPM range and I don't know what yours is though. If it is running closer to its rated RPM I don't think you will need as much head room at the top end of the ESC to maintain head speed compared to running in an inefficient range.

Example: My motor has a max rated RPM of 25,000. With the 15T it runs around 23,000 but with the 16T it runs at about 21,500 to give me the same head speed. It has been stated that Hackers run more efficient closer to their rated max but other motors probably have a different sweet spot.

The biggest thing to take away from this whole thing is to put a pinion on your motor, set your TC to what gives you desired head speed, and then pitch pump/hard climb out the helicopter and see if it bogs. If the two different pinions give you the same performance but one makes the system run cooler than the other - go with the one that runs cooler. Your batteries, motor, and ESC will probably last longer. Make sure you do the comparison with the same battery. My new battery holds the head speed constant under all maneuvers but the old one bogs ( 90+ flights ) since I don't think it can hold the voltage as high under load and efficiency of the ESC isn't going to help.

Question:
When you ran the 14T you had 2300 HS but how did the performance seem? Did it bog?

What kind of flying are you mostly doing?

On another note:
The Arctic Silver should be mixed and applied quickly since it has a short cure time. Its best to keep as thin a layer as possible so the heat sink is closest to the heat plate on the ESC. You'll also want to make sure you have complete coverage with no holes. Just spread it and slide the heat sink around on the ESC until you get even coverage. You can even pull back off within the first 30 seconds or so to make sure it has spread properly.

You can always make a small batch and do a test with metal to metal and see what happens.

Bruce

[Mathias]

Thanks, Buce!


I did just change the pinion to a 14T/85%, and I'll see how it goes when I possible get a chance to fly it tomorrow.

When I ran the 14T, I did actually just tach the HS to see which HS I got.

The 15T/HOT temps made me decide changing back to the 14T.

I'm flying FF, Tic-Tocs, inverted, rolls etc... Not hard stick banging, but I do like much response and a nice working governor since my collective management isn't the best out there. ;)

I need to trim the heat sink a bit before I install it, but I'm not sure what to cut it with. Thanks for the tips!

I'll see how it goes!


Thanks,

[BruceW]

I used a dremel with the cutting wheel then filed/rounded the edges. It is also just slightly smaller than the heat plate on the ESC so I could slide it around to set it.

[Mathias]

I need to cut it... tried the dremel w/ cutting wheel, but with no luck.

[itsparks]

I need to cut it... tried the dremel w/ cutting wheel, but with no luck.

It takes a few min to cut it, you don't need a huge heat sink, do you have a picture of what you are trying to use ?

[billyd]

Regarding tc % the only way to know would be to use a data logger and see if your hs is dropping during extreme maneuvers. Certainly it doesn't matter too much if the HS drops and there is no noticeable bogging. to speak of. I have stated every time regarding the 70% number that that was what I was told and never wanted to act like I "knew" it for certain. Every setup is different. Motor/pinion combos will change efficiency substantially from one setup to the next.

I found with my particular setup that when I got into the 80%s on my TC I was hitting resonant frequencies in my heli and it was no good, the head speed was too high. Orbit 25-8 with 15t. I have heard that the 14t will run the Jazz cooler but at a substantial hit to flight time. I still believe that the problem lies with the Jazz and it's poorly designed cooling (e.g. none). I am not even using the bec, which is where most ESC's get their heat.

[itsparks]

So weird, i never hear problems with the Jazz, ive never had a problem either, maybe where you guys live there is way to much heat, UP here in Canada B.C its pretty cool weather, nothing to extreme.

I do like how Castle put a nice big heatsink on their esc's. If my stock align one dies, ill be switching to one to see how good they are.



Jase

[Mathias]

It takes a few min to cut it, you don't need a huge heat sink, do you have a picture of what you are trying to use ?http://www.elefun.no/elefun4/aspx/produkter.aspx?vareID=8573&itemref=2&prod=Hyperion%20Heatsink%20for%20Titan%2050A/80A%20ESC&kategoriID=10000

That is the one...