Help: Setting governor Hobby Wing Platinum 40A ESC

[hookedonflying]

Okay, I'm a little confused. I'm trying hard to understand this, but I'm very confused by this manual. Please be easy on me. lol

Here's what I have:
Tarot 450 Pro DFC
Alpha Power 3800KV Motor(8 poles apparently, but I count 9 windings???)
Hobby Wing 40A ESC
ZYX-S Gyro
150T gear
13T pinion
(but changing to 121T helical 11T pinion)
3S Glacier 2100mAh 30C



I'm trying to understand how to set my governor head speed. If I follow the formula on this manual and look at the chart using the 20% headroom rule, I see that it intersects 80% throttle at 90000rpm. So I plug in the formula and get (90000 x 13)/4/150 = 1950??? Can that be possible? Running without governor, but with a V curve 100-92-84-92-100 it doesn't sound at all like it's even close to that slow in a hover near mid stick. I'm no expert, though. At 90% the formula gives me 2990rpm.

Where in the world does the KV value of the motor come in? I don't see it anywhere in this manual.

Using headspeed calculators (Rotor RMP Calc (basic)) with my setup and the 3800KV motor I get 3356 at 80%, or 3521 with the 121T helical and 11T pinion.

Please help me sort through this mess. I want to get this heli running properly and well so I have no excuses when I crash it.

I also need to set up my ZYX gyro properly, I assume. In the advanced settings it has a Governor page where it gives Governor off or Calibrate RPM. Then when you click Calibrate RPM it brings up the gain settings (total gain, I gain, P gain, D gain) Disturbance Compensation (collective comp, Cyclic comp). So am I correct that once I get the RPM setup correct on my ESC and pinion and such, I manipulate these settings in my gyro to "control" my ESC? Sorry for the LOOOONG post. Thanks so much for any help.

[hookedonflying]

Really? Nobody can take a shot at this? I need you, my fellow freaks.

[minatrix]

For an 8-pole motor the rpm numbers in the graph would all be divided by 4. This is really to determine whether you should be in gov high or gov low setting. So for an 8 pole motor, gov low is for motor rpms of 2,500-11,250, gov high is for 11,500 - 50,000 rpm.
Your motor rpms will be (motor Kv)x(batt voltage)= (3800)x(11.1)=42,180 motor rpms. Keep in mind that a full 3 cell will actually be 12.4 volts, but for governor use we want to use numbers that will be acheivable as the battery voltage drops during flight, hence the 11.1V used.
So the motor rpm puts you in the high gov range. I'm not sure about those numbers in their formula. Headspeed would be approx. (42,180*13)/(150)=3,655 at 100% throttle. 80%=2,925 rpm.
I would set the esc to gov high, very soft start (important). Be sure to calibrate your throttle response.
The governor will either be the the esc or the zyx, not both. If your are using the hobbywing gov the zyx should have gov set to "off".
I would start with 3 flat throttle curves of 70%/80%/90% (if you have 3 flight modes), or 75%/85% if you have 2 flight modes. This assumes you will not have a normal mode, and will spool up using the soft start in the esc, by switching out of throttle hold. You can tach it and adjust or tune it to your liking. Keep in mind the gov disables below 60% throttle, and usually 10% headroom is enough.
I notice the tarot site lists these models as coming with a 14 tooth, maybe double check your pinion tooth count.

[hookedonflying]

Minatrix, thanks for the reply. I appreciate you taking the time. I guess that chart isn't really for picking a headspeed. I'll try it out.

So thanks for mentioning the "turn off governor" on ZYX. I would have turned it on thinking somehow they work together. I guess to use the ZYX governor I have to buy something I don't have? An external governor? Is it better to use the ZYX governor, do you think? It looks like it would allow much more tweaking for the liking.

[minatrix]

Hobbywing governors are pretty good. I don't know much about the zyx gov, but you do need a zyx20 expansion board and would need to add a hobbywing phase sensor. I would use the esc gov for simplicity's sake.

[hookedonflying]

Awesome, I'll try the ESC gov first, and go the alternate route if I don't like it. Thanks so much.