Governor help

[Gtamas]

Hi!

I've got a 450L dominator with 460mx 1800kv (6s) motor.
I'm using YEP 90LV ESC which has an rpm output.

In the Gov setup menu, i cant get accurate current rpm. The motor has 6 magnets, but 9 stator arms. How many is the pole count? if i set 3 to spirit, i get 3200rpm current rpm above 50% throttle. if i set 4, i get maybe correct rpm read at lower throttle, with 5 divider i get better readings at high throttle. but non of this is correect.
The gear ratio is correct, 11:1. 11t pinion, 121t main gear.

it seems it would be good if i can set a 4.5 pole divider. I'm stuck now, please help

Here you can find pictures about the inside of the 460MX motor:
http://www.helifreak.com/showthread.php?t=636351

thanks.

[smgunn]

You have 9 stators and 6 poles. All stators will be multiples of three in a brushless motor. You need to set the sensing divider to 3. The stock gear ratio is 11 I think. 121tooth main gear and 11 tooth motor pinion.

[Gtamas]

Thanks for reply!

That was my first try, on helifreak they said it has 6 poles, but with divider 3, i get no current rpm until around half throttle, then immediately it changed to 3000 something, and it didn't changed any on the 50-100% throttle. With higher divider it's changing.

Maybe something is wrong with ESC rpm out? Its a brand new ESC, working great, its own governor is working, but i wanted to try the spirit gov, since on its lowest gain, i cant set the tail to not kick any.

[Adrian]

If you have nitro, divider would be 1, on outrunner brushless motor, take pole (magnets) count divided by 2. In your case 6mgnets / 2 = 3.
Remark: On brushless, you have a multiple of 3 on Stators (windings) and an multiple of 2 on Magnets Pols as they are placed: North - South - North - South - .....

If you use Spirit Governor, below 40% Throttle out is send direct (transparent) to ESC, Spirit Governor engages above 40%-50%.
Running on bench, you should see it on Spirit under GOV Settings PRM Meter, once above 50% there will be requested rpm as well as current rpm.
Remark: This allows you to start and adjust nitro idle power or keep bailout level for ESC with bailout functionality.

Requested RPM is calculated based on max RPM * Throttle 0..100% from TX. Example: 2400 * 70% = 1680rpm
Now current rpm should match up with requested, if it can't be reached, requested might be to high or throttle range from Spirit won't match ESC.
If requested equals current but you got the felling its to low or to high, then there is an issue with rpm out, sensor or divider.

[Gtamas]

Yeah, i know.

Now i set it to 3.

blades off, straight 0-50-100 throttle curve on tx, to test. max rpm is set to 3500

above 50% requested, and actuel rpm appears. But if requested is 2000, the actual is 3200, and if i move the throttle up, actual stays at 3200, until requested reach 3200, after that they goes together.

Is it because no load on the system? in the air it will work correctly?

[Adrian]

What Spool-up rate have you configured?
What happens if you toggle Throttle curve (F-Mode) after spool-up?
I have seen on my system with Spool-up set "fast and very fast", if ESC Spool-up is slower than requested Spool-up ramp from Spirit, Spirit Gov. gets kind of locked in with to high rpm.
Solution: Switching up/down Throttle Curve, increasing Spool-UP speed in ESC or reducing Spool-up in Spirit helped.

[FrankFuss]

Is it because no load on the system? in the air it will work correctly?

With my Trex 450Ls (different FBL and ESC) I found that the headspeed at different throttle percentages with blades off is not even close to what you get with the blades on. You must have the blades on to get consistent results.

[Gtamas]

yeah, that's what i thought, i try it next time with blades on...