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Q80 14XS set up

Started by Peter Jenkins, 05, August 2019, 11:48:21 AM

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Peter Jenkins

I've just installed a Q8014XS in my Citrin.  When setting up the Spin 99 I found I could only select either 8 kHz or 32 kHz.  The data sheet on the Q80 says 16 kHz is the required switching frequency.


I've set 32 kHz but would appreciate someone who knows about these things telling me whether to set 8 or 32 kHz.


Thanks


Peter

Phil Lewis

i would try 8 first and see how it runs, if it runs smoothly enough use it. At 32 the ESC is doing four times as much work which may make it overheat and is likely to shorten it's life.


Phil

Peter Jenkins

Thanks Phil.  Will reset to 8 kHz.


Peter

Mike Wood

and email Hacker / Jeti.

Both have replied with detailed answers within a day in the past

    Hacker:   info@hacker-motor.com

    Jeti:        support@jetimodel.cz

Mike

Peter Jenkins


Mike Wood

Hopefully their advice will match up  ;) :) 8)


Mike

Mike Wood

Hi Peter

Those last two email addresses were from the last emails I exchanged with them.

From the websites the current addresses are:

    jeti@jetimodel.com

    shop@hacker-motor-shop.com

So perhaps best to send to both!?!?

Mike

Malcolm Harris

Peter,

8 kHz is the standard setting for all the Q80s we have run.

From the Spin 99 Manual

Motor control modulation frequency within the regulation range. Always use
8kHz. The only exception are the so called iron free motors (Tango, Samba). For
these motors a frequency of 32 kHz must be used.


Malcolm

Mike Wood

#8
Nice ... that's definitive.

http://www.jetimodel.com/en/show-file/125/   Page 25

m

Bob Wasson

Hello Peter,


Being fairly new to Q80's I also sought guidance on recommended settings.  My main source of information was Ralf Schweizer.  Ralph was extremely helpful.  Not only that, but as an avid tester and developer, I suspect that he has probably as much knowledge and user experience of the various different versions of Q80 as anyone else alive.  A summary of my trawl for information from Ralph and other trusted sources was as follows:


Avoiding excess ESC and rotor temperatures is critical.  Good cooling set ups for both items of hardware are essential.  With a Q80, a well cooled ESC can run at 150C to 200C above ambient.  Less is better for longevity.    The motor can normally handle up to 600C after a flight.  800C after a flight and the magnets will eventually come loose.  Bearing problems may also develop.  (For those without temperature data logging facilities, the guidance 500C OK to carry, 600C OK to touch but not to hold, may help to put things in a broader non-scientific ballpark.)

       
  • Recommended frequency for Q80 14XS is 8 kHz (cf Hacker recommendation of 16 kHz).  [As Phil says, this helps to reduce the workload on the ESC, thereby keeping it cooler. Malcolm's quote from the Jeti Manual is also supportive of this view].
  • Recommended timing is load dependant.  Hacker recommend 240.  Ralf's recommendation for everyday flying with high load propellers such as a 20x13 3-blade is 200 maximum.  If necessary, to gain more power for windier conditions, this can be increased in stages up to Hacker's recommended 240.
  • With high load propellers, the acceleration time set for the Spin 99 Opto is also important.  Otherwise synchronisation issues may develop.  A minimum of 0.8 secs is recommended, more for fresh low IR flight batteries.

I flew my well-seasoned Gaudius through the midst of the recent UK heatwave.  It was retrofitted with a Q80 14XS and a very efficient high load RSM2 3-2 3-blade propeller.  The original Spin 99 Opto was retained and close attention was paid to providing a strong supply of cooling air to both the motor and the ESC.  Settings for the latter were as follows:

       
  • Frequency – 8 kHz
  • Timing -  200
  • Acceleration 1.0 secs


Much to my surprise, after a series of 7 ½ minutes flights in 340C to 360C ambient, both the Q80 Rotor and the Jeti 99 heatsink were barely warm to the touch.  The motor/propeller set up developed power aplenty, and I noticed no detrimental effects in terms of either response or smoothness from running at these settings.  I could even have mounted an argument to say that the higher than normal setting for acceleration added to the smoothness of the flight!


Hope this helps


Bob

Peter Jenkins

Hi Malcolm and Bob


Many thanks for your advice and pointers.  I do have the Spin manual to which you referred but was going by the Q80 spec which quotes Timing at 25 deg and Switching Freq at 16 kHz.  I have already re-set the Switching Freq to 8 kHz and will now drop the timing to 20 deg.  Accel is at 1.0.


I am expecting good cooling as the Q80 is in a Citrin and the cooling air entering between the spinner and the cowl looks to be directed at the copper wire coils in the motor!  I hope that after flying a P19 that the motor will be touchable but we shall see!


I have also emailed Hacker and Jeti and will post when I get a reply as to why Hacker specify 16 kHz and Jeti don't!


Peter

Peter Jenkins

Hacker has just replied and said use 8 kHz.  They referred me to their website but I couldn't find any reference to switching frequency.  Suffice to say that their data sheet on the Q80 14XS states 16 kHz!  Left hand and right hand methinks! 

Mike Wood

That's a nice fast response from them!

m

Peter Jenkins

#13
Flew the Citrin/Q80 this evening starting with 20 timing.  On landing the motor temp was 32 C for an ambient of 24 C.  Not bad!  I felt I'd try a slightly higher timing so upped it to 23 but I also felt the throttle curve needed raising.  I have yet to fly with the new throttle curve.  I don't know if it was imagination, but the Citrin seemed to fly a bit better than with the C50 - perhaps that's been on the blink for some time.


Thanks for your help fellas.

Peter Jenkins

Have now heard from Jeti who say:


Dear Sir,
[/size]please use 8kHz and timing min. 25°.
[/size]Best Regards

[/size]JETI model s.r.o.