more Jazz overtemp problems

[th3tick]

So this past week, I took my L500 out and flew it, but had temp issues twice. I flipped (finally) the ESC, cut the plastic off, and put a small heatsink on it (just strapped on at this point).

First flight went well, with no issues, aside from awesomeness ;) I upped the aileron gain to 200 as others had advised, and it's really alive now. Next I'm going to try 220, but I'm not sure about elevator, which is already at 300.

Second flight had an overtemp about 4 minutes into the flight. After landing and hauling it back to where I had a temp sensor, it read 168 on the caps. YOW!

It was in the 90s this morning, so nothing TOO terrible, and I probably should have waited longer between flights, but 1/2 hour was about my mental limit. I wanted to FLY!

Just not sure what I can do to get the temps down on this Jazz. It's hooked to a Neu 1910/1Y/H, and I'm flying at 75% throttle, getting around 2300 headspeed.

Suggestions appreciated...
John

[Eyon]

not sure about the jazz, but get that aileron gain higher :D:D:D:D

[jamesotron99]

I think I had my first thermal on my Jazz 55 yesterday, the RPMs drop suddenly, right? Strange thing is that the ambient temperature was only about 11 degrees celcius!

[th3tick]

Yup, loss of headspeed. It continues to drop for a while. Check the ESC light blinks to tell you what happened. Three blinks for overtemp.

John

[rwharrisjr]

John,

Just went through a lot of testing with a Jazz 80 and Tango 45-10 on a Logo 500. You have to get the throttle above 80%. I started off running a mod 0.5 21 tooth pinion and at 75% I thermaled at 185F. Changed the throttle to 80% and the temp went down to 130F same flight conditions as before. I am running 6s. If I go above 83%, the head speed will decay slightly ~40 rpm, as the pack voltage drops during flight. I have a second Logo 500 running a Jazz 55 and Tango 45-10, also 6s, which works well at 80% and a 21 tooth pinion. I've dropped to a 20 tooth on the Jazz 80 heli. I get ~2200 rpm head speed from both. Today I flew the Jazz 80 with an ambient temperature of 90F and after a 7 1/2 minute flight ( I'm a sport flyer) the Jazz 80 was 135F. If I had it to do over again I would have stuck with the Jazz 55. I run EagleTree recorders on both helis and the Jazz 55 is a more efficient ESC IMHO.

[jamesotron99]

Good point. I think I have mine dialled to 75% also, so I'll up it to 80% and see if it happens again. Thanks.

[th3tick]

Thanks for that. I'll bump it to 80, and I already have an eLogger on it to see where the headspeed lands. At least on the 16T, I can lower it if I need to.

John

[jamesotron99]

John. Let me know what luck you have - we have almost identical configurations - except I have a jazz 55.

[th3tick]

OK, got a couple flights in this morning with the ST1 setting at 80%. First flight was 5 minutes (still breaking in that pack) and it came down at 135. I threw caution to the wind and put in a second, broken-in pack, and flew again immediately.

This time, it came down after 7 more minutes at 130. I think we have a WINNER!

Thank you, rwharrisjr for the suggestion!

My eLogger is misbehaving this morning, so I don't have the resulting headspeed, unfortunately. Still, it flew like a champ (especially on the 220 aileron gain - time for 240!).

John

[BruceW]

I'm running 86% on my Jazz 80 (15T) and the final temp is about 122F->128F with ambient around 80F. When I went with 16T and 75% everything was much hotter but I didn't have a temp sensor at the time to get an accurate reading. Even though I added the heat sink, it didn't really drop the end temperature by much except on hot days.

[th3tick]

I think my next option is to do the math and see whether a 15T puts it in a better range for my desired headspeed (2300?).

In any case, it'll be nice to be able to just go and fly. With so much power, and such rock-solid flight characteristics, it's a joy...

This is why I miss the 1912 on my L600, but am working on that too ;)

John

[th3tick]

Just a post-crash follow-up. My headspeed on this 80% is around 2400. :smokin:

Still, flies awesome right up until the the buzz-saw like snapping sounds...

Maybe I should throw a 12T on there for the rebuild...

John