RPM with Jass ECS advise. Eagle Tree Graph Attached

[02deuce]

The question is, are the RPM drops on the attached eagle tree graph typical for the Jazz 40-6-18 or is my head speed to high for a flat 90 TC.?


I just started flying 6 months ago and am new to the hobby. My set up is 450 v2 stock motor 12T, Jazz 40-6-18 pitch +-12 Cyclic+-6. Align Carbon 325 blades ( the good ones) FP2170 pack and the tail mod.
The first couple of minutes is circut flying the duration is Flips and rolls which I just started doing WHOO WHOO.

I am under the impression that the jass maintains a very constant RPM, how much RPM drop is normal when doing basic sport flying?

Thanks for any advice or input to my question and current setup.

[prototype3a]

That looks about normal from what I understand. I believe how much the rpm drops depends a great deal on your setup but 200rpm isn't too bad or anything to worry about. If I'm reading it right it didn't go much below 2800rpm. Normally that's where I fly at so no worries.

[GreenCello]

I'm using the same set up with a 75---75 at 2850 blade rpm. Jazz holds with less than 100 rpm drop usually <50 so perhaps you need a 13th if you want to maintain the 3000 rpm.

[02deuce]

I thought that going up in pinion will increase the bog (more RPM less Torque) ?

[XsinkrateX]

you would think that a 1300rpm difference/change is not normal. but i wasnt there to see you fly

[02deuce]

My actual max RPM drop is 200. I am thinking about dropping to a 11T pinion to lower my head speed which should give me more torque. For my level of flying I dont think that I need 3000-3100 RPM HS. But I'm open to suggestions.

[TomRex]

Open to suggestions,, try a Neu

[02deuce]

Thanks!!! TomRex I apperciate the suggestion, but I just recieved my HK2221-6 V2 Scorpion yesterday, I hope I made the right decision knowing the motor way exceeds my flying capabilites.

[airjawed]

Maybe you didnt give yourself enough headroom? The governor needs to be at 80% max at zero pitch..otherwise you don't have any more throttle left to correct under loads. Seems that the 12t maybe not be the right choice...try the 13t out...

Did you find out what your max headspeed is at zero pitch and then set it around 80% of that? Setting up the governor mode is tricky... a lot of misinformation....just like gyro setups.

I have the align esc 35x and align motor 430xl...I'm governed at 3000 rpm...works very well with the 13t...tried the 12t because i wanted longer flight times but the rpm drops were too much...the 13t held better...don't have a flight logger to confirm this though.

[TomRex]

Don't get confused with the lesser brand esc's.
The Jazz will hold 10% for head room even if its set at 100%
I found the best rpm hold to be no higher than 85%flat across for gov mode.
I run 4s and a Neu H motor, a great combo with the Jazz.

[02deuce]

Thanks for all the feed back. I didnt do anything special on setting up the Jazz, I believe I Just programmed it for Heli mode and thats it. Plug and Play

[airjawed]

I've heard very good things about the Jazz esc governor mode... but no matter the esc it needs to vary output..and for this it needs headroom...may it be 10% or 20%...and the setup should be running at the motor/esc optimum power band so to speak... brushless motors in theory are limited only by the power supplied to it....gas engines have more of a power band...but both do end up with a power band...

So to set up things properly one needs to determine the max available output(measured as max headspeed)...and run at a lower level so that under max loads there is ample extra power available for those conditions.

In theory put the heli under max load.....see what the headspeed is...and that would be the goverened speed to achieve...that way there would be zero drop in headspeed...but reality is a give and take situation...we'll set a headspeed that gives us acceptable drop in rpm.

[02deuce]

Well, what is acceptable RPM drop for the Jazz? If I am dropping 200 RPM doing simple flips and roll is that normal, or is my ESC setup wrong? I have seen graphs of the Jazz that the RPM looks almost flat line under a load. Or am I expecting to much from my XL Motor and the ECS?

[blueviewlaguna]

Originally Posted by 02deuce

Well, what is acceptable RPM drop for the Jazz? If I am dropping 200 RPM doing simple flips and roll is that normal, or is my ESC setup wrong? I have seen graphs of the Jazz that the RPM looks almost flat line under a load. Or am I expecting to much from my XL Motor and the ECS?

I am having the same exact issue with my Neu 1107/2Y - I run 75% flat across, let the headspeed stabilize, reduced the pinion for more "leverage" but the Jazz just lets the headspeed drop about the same 200 rpm as yours with either pinion 12T or 13T, yet I see nice flat graphs with the Jazz from other posters.

https://www.helifreak.com/showthread.php?t=79890

[02deuce]

Man o Man Just buried my v2 into the ground attempting a back flip with new Radix blades. I was about 15' off the deck and was expectioning a fast flip rate with the new blades (thats why I bought them) but as soon as I pulled back on the elev. I knew I was in trouble as it just rolled back like it was in slow mo and I didnt have enought space to recover. I am still puzzled as to why? I did a preflight in normal mode for one pack and all seemed ok. Well it looks like about $150.00 in parts. I did notice that I dropped about 600 RPM in head speed when I started into the back flip. ARGGGG

[Wildcat9]

I put this in the other guys thread...might as well put it here too
Program the Jazz with a 0-25-50-75-100 throttle curve in your transmitter. Once you've programmed it to mode 4, then put in your desired throttle curve in the transmitter. Remember to leave 20-25% head room for the governor to do it's thing and pinion your motor accordingly.

[Mystic3D]

02Deuce... Hmm Sounds familar. I think you must be from Willis not Houston as I think I was the witness to the 15' backflip crash.
re the Scorpion has known bearing issues, maybe the Neu is better...

[ktm520]

i think its a combination of a couple variables. the biggest being collective management, and the second being the power available from your motor. lastly, it is important to gear correctly when using gov mode. yes, the jazz is smart enough to leave some headroom even if you are using a 100% flat curve, but in my experience that is still not enough. i would the try the 13t pinion before the 11t with the stock motor. the scorpion motor should be an improvement over the stock motor.

for example, i just built a G5 and initially set it up with a 3s power system using 450th (not the most powerful motor around) for comparison purposes. it was a dog on 3s with the 450th at 2900 hs. this same motor on my 450se worked pretty well, but it is 150g lighter and spins shorter blades. i switched to the 6s power system on the G5 with a mere 2400 hs and it was hard to bog the head even with very, very poor collective management.