This should really help get the correct prop and the correct gearing on your Heli...
I put this in quotes because I pulled this from another post I made... Thanks for reading....

" You can use the Castle data log to find the "Running KV" of the Motor ... In the native gov set the HS 3 to 4000 RPM ( this is to get the motor to run at 100% ) you can also run in fixed endpoint and make sure you are running 100% in the data log. In Set RPM Gov the IDEA is to get the motor to run Flat out... clear the Data Log...then run the Heli with blades off or pinion disengaged so you can get the motor to run at 100% un loaded... Then on the graph viewer you can download the data from the esc.... change the gearing to 1 to 1 and then in the graph scroll over and you get the vertical line that shows voltage and motor RPM at that time ( ame Mouse position ) ... divide motor RPM by Voltage and you will get the KV of the motor and you can use this in the Castle link setup instead of the rated KV as this is the information you are feeding the Castle Link for the advisement part of the program..."

Try it... you may be surprised...

yep.. my 440 kv motor calculates to 478 kv.. With my Logo 600se and lowest gear 11t on 12s, its still over geared.. No wonder..

This is a valuable setup tool...

Thanks..

We checked motors at IRCHA and folks were surprised to see how far off some ratings were....

Originally Posted by Clintstone

... In the native gov set the HS 3 to 4000 RPM ( this is to get the motor to run at 100% )

Is the 4000 rpm a "magic" number for all heli motors , ie do I use this set HS for all my motors with CC ESC's ?

Originally Posted by teamlotus

Is the 4000 rpm a "magic" number for all heli motors , ie do I use this set HS for all my motors with CC ESC's ?

No magic number the idea is to get the GOV to run the motor flat out at 100%. you will see the motor out put at 100%...

It is possible for a smaller Heli to have a HS of 4000 or greater so you need to make sure that the HS you enter is high enough to run at 100% you can see this in the graph so it should be easy to sort out.


The example of 4000 that I used was on a Heli GOV at 2000 HS around 95% in Set RPM mode... So this model could not get to 4000 RPM so it was running flat out at 100% ....

Originally Posted by teamlotus

Is the 4000 rpm a "magic" number for all heli motors , ie do I use this set HS for all my motors with CC ESC's ?

The number has to be high enough so that the motor is running at 100% full throttle. It’s possible that a very small helicopter would need to have that number higher.

.

Will this work with just a full throttle run ( no prop) using a controller in airplane mode as well? auto or fixed end points?

Originally Posted by rotomatt

Will this work with just a full throttle run ( no prop) using a controller in airplane mode as well? auto or fixed end points?

Just plot the Power Out parameter too. It should be 100% at WOT. If it is, then yes you can calculate Kv with the method.