gov on stock ESC, not too bad, high VS low ??

[dannylightning]

so i tried it out on gov high, 55% throttle vs 92% throttle curve and i did not really notice any head speed change, that is kind of strange, not sure what gov low is going to do, i would imagine give me less head speed or make the gov react slower.

any ways, the gov on the stock ESC works, not as good as a castle IMO but better than nothing, the head speed sounded pretty high, i dont think i lost any head speed.

only flew one pack, 20 some mph winds and a smaller than preferred field for the X5, i set up my helicopter, and i hear a big bang, look over and some ones trash can blew over, the X5 did not mind the wind, just pitched up and down a bit. over all i was happy with the way it flew, i just want to know what the best gov settings are going to be and how this gov works

on the castle 30% or more gives you one head speed, 70 or more gives you the second and 100% throttle curve gives you the 3rd head speed, is that how this one works and what aboug gov low, what will that do

[Chris Sexton]

No the gov mode on the stock esc is much simpler.

On Gov HIGH you are enabling governor mode and setting the head speed gain to HIGH. What happens is once the ESC sees a throttle position it will use gov to hold that head speed. So if you set your IDLE up to 90% throttle flat curve and set soft start, the bird will spool up to 90% throttle. Then when flying the esc will increase or decrease the power to maintain the head speed you had at no load. The HIGH gain will make it attempt to hold the head speed with extreme sensitiveness and is really hard on TT gear, IMO.

Gov low is the same thing with a "Low" head speed gain.

Your Castle offers this mode, but what you, like me, are accustomed to is "Set Head Speed Gov Mode" which the stock Esc doesn't offer.

Kind of wordy, I hope that makes sense.

[Chris Sexton]

oh and you can set different head speeds by using different throttle curves but you would need to either run the math to see where you are or tach it.

most Pilots that I know that fly with this GOV low mode, have just one throttle curve and forget it.

[dannylightning]

So i should try gov low. Not seeing a head speed change when I flip the switch. Is what has me wondering. The head speed also sounded really high too

[Harrow]

Originally Posted by cdsexton

oh and you can set different head speeds by using different throttle curves but you would need to either run the math to see where you are or tach it.

most Pilots that I know that fly with this GOV low mode, have just one throttle curve and forget it.

I don't think you should use GOV LOW with the stock motor. It depends on how many poles your motor has whether you should use GOV HIGH or GOV LOW. For the stock 910kV scorpion (which has 8 poles), you need to use GOV HIGH.

According to the ESC data sheet, GOV LOW goes to a maximum of 44000rpm (for a 2 pole motor) so for an 8 pole motor that gives 44000/4*16/120 = 1467rpm head speed. Not enough.

Look at the curve on the ESC data sheet, and you see that GOV HIGH with a throttle of 70% gives 70,000 rpm for 2 pole motor, so for the stock 8 pole motor you get 70,000/4*16/120=2333 rpm head speed.

Okay, that is the theoretical stuff, now for some practical results. I tested my governor mode yesterday. I'm running all stock gear including the 16T pinion. I set to GOV HIGH, spun the heli up, and with zero collective, I slowly changed the throttle %. Note that the governor does not start working until throttle is 60%, and that is exactly what happened for me. (In fact, at 59% throttle, your head speed is actually higher, then it drops when you go to 60% as the governor cuts in.)

Here's my results:

60% - 63% 1650
64% 1710
65% 1770
66% 1830
67% 1890
68% 1950
69% 2010
70% 2070
71% 2160
72% 2250
73% 2340
74% 2430
75% 2520

Note that between 64 and 70% each 1% adds 60rpm. From 70% upwards, it adds 90rpm.

Probably also important to note is that 72% gives 16875rpm for the stock motor and 73% throttle gives 17550rpm, which is 16% and 13% head room based on the maximum 20202 rpm of the motor (910kv * 22.2v). Therefore my plan is to run either 72% or 73%, and then change the pinion to give the head speed you want.

At 73% throttle on GOV HIGH, the different pinions will give the following head speeds:

13T 1901
14T 2048
15T 2194
16T 2340

Oh yeah, also important was that I applied full negative pitch (12 degrees for me) to see how the head speed changed. I only did this at one speed after seeing how much the landing gear flexed. The speed held precisely. Of course, if you set a very high throttle and head speed, you can not be guaranteed that your power system will be capable of this as you batteries drains, but from my tests, it seems the ESC is going to hold it's side of the bargain, and the rest will be up to your motor and battery.

Okay, enough rant from me, I hope this is of some help to somebody.

Regards,
Harrow.

[dannylightning]

Originally Posted by Harrow

It depends on how many poles your motor has whether you should use GOV HIGH or GOV LOW. For the stock 910kV scorpion (which has 8 poles), you need to use GOV HIGH.

According to the ESC data sheet, GOV LOW goes to a maximum of 44000rpm (for a 2 pole motor) so for an 8 pole motor that gives 44000/4*16/120 = 1467rpm head speed. Not enough.

Look at the curve on the ESC data sheet, and you see that GOV HIGH with a throttle of 70% gives 70,000 rpm for 2 pole motor, so for the stock 8 pole motor you get 70,000/4*16/120=2333 rpm head speed.

Okay, that is the theoretical stuff, now for some practical results. I tested my governor mode yesterday. I'm running all stock gear including the 16T pinion. I set to GOV HIGH, spun the heli up, and with zero collective, I slowly changed the throttle %. Note that the governor does not start working until throttle is 60%, and that is exactly what happened for me. In fact, at 59% throttle, your head speed is actually higher, then it drop when you go to 60% as the governor cuts in.)

Here's my results:

60% - 63% 1650
64% 1710
65% 1770
66% 1830
67% 1890
68% 1950
69% 2010
70% 2070
71% 2160
72% 2250
73% 2340
74% 2430
75% 2520

Note that between 64 and 70% each 1% adds 60rpm. From 70% upwards, it adds 90rpm.

Probably also important to note is that 72% gives 16875rpm for the stock motor and 73% throttle gives 17550rpm, which is 16% and 13% head room based on the maximum 20202 rpm of the motor (910kv * 22.2v). Therefore my plan is to run either 72% or 73%, and then change the pinion to give the head speed you want.

At 73% throttle on GOV HIGH, the different pinions will give the following head speeds:

13T 1901
14T 2048
15T 2194
16T 2340

Oh yeah, also important was that I applied full negative pitch (12 degrees for me) to see how the head speed changed. I only did this at one speed after seeing how much the landing gear flexed. The speed held precisely. Of course, if you set a very high throttle and head speed, yuo can not be guaranteed that your power system will be capable of this as you batteries drains, but from my tests, it seems the ESC is going to hold it's side of the bargain, and the rest will be up to your motor and battery.

Okay, enough rant from me, I hope this is of some help to somebody.

Regards,
Harrow.

thanks, all the math stuff does not compute in my brain yet.

with the stock 910kv motor and 15T pinion what throttle curve will get me 2400 and 2500 rpm, that is what i would like I1 and I2 to be.

[Harrow]

Originally Posted by dannylightning

thanks, all the math stuff does not compute in my brain yet.

with the stock 910kv motor and 15T pinion what throttle curve will get me 2400 and 2500 rpm, that is what i would like I1 and I2 to be.

All you need to do is take my list of actual test results, and then scale for the different pinion size. So, since I got 2520 with 75% and 16T, with a 15T 75% will give you about 2362.

Not sure you'll be able to achieve what you want with 15T. With 100% throttle, you should be maxing out at 2525rpm (910x22.2*15/120), and have no head room at all.

Ideally for those head speeds I think you should be using 16T at 73.5% and 76%, but even then, the headroom is getting a little low for the higher one, so it might start to bog at the end of the battery, I don't know. Test it out and let me know if it works out.

Regards,
Harrow.

[dannylightning]

Originally Posted by Harrow

All you need to do is take my list of actual test results, and then scale for the different pinion size. So, since I got 2520 with 75% and 16T, with a 15T 75% will give you about 2362.

Not sure you'll be able to achieve what you want with 15T. With 100% throttle, you should be maxing out at 2525rpm (910x22.2*15/120), and have no head room at all.

Ideally for those head speeds I think you should be using 16T at 73.5% and 76%, but even then, the headroom is getting a little low for the higher one, so it might start to bog at the end of the battery, I don't know. Test it out and let me know if it works out.

Regards,
Harrow.

Thanks, i will set at 75% and see how i like it, if it still has nice 3D performance ill be happy, i will also set at 80% throttle curve too and try that out...

if its to low ill switch to the 16T pinion, just don't feel like pulling the motor off if i dont need to..

[FIGAAATELLU]

very good explanations !!
i will test gov mod this week end !!

also I have read somewhere that over 75% throttle, the gov is going to 100% directly !
so be carefull !!

[onemetre]

Great info!!!

Rob

[Harrow]

Originally Posted by dannylightning

Thanks, i will set at 75% and see how i like it, if it still has nice 3D performance ill be happy, i will also set at 80% throttle curve too and try that out...

if its to low ill switch to the 16T pinion, just don't feel like pulling the motor off if i dont need to..

From my test results, 75% on 15T should give you 2363rpm. You'll have 18% headroom at the beginning of the battery and about 6% toward then end, so I'm guessing you'll start to see bogging at the end. Still, I expect you'll see more consistent head speed throughout your flight than a standard fixed throttle curve, and any bogging you get at the end would still be there without the governor anyway. I'll be interested to hear what your experience is after you do a comparison.

[Harrow]

deleted. I tried to post an excel spreadsheet, and it didn;t work.

[dannylightning]

Originally Posted by Harrow

From my test results, 75% on 15T should give you 2363rpm. You'll have 18% headroom at the beginning of the battery and about 6% toward then end, so I'm guessing you'll start to see bogging at the end. Still, I expect you'll see more consistent head speed throughout your flight than a standard fixed throttle curve, and any bogging you get at the end would still be there without the governor anyway. I'll be interested to hear what your experience is after you do a comparison.

at 2500 rpm flying for 5 min my packs come down at 3.80V per cell, using the gov at 75% should give me a head speed i am happy with i would think,, probably longer flight times too. so ill stick with 75% 5 min flights and i am guessing i wont really see any bogging

after 5 min at 92% throttle running the gov, doing nothing but tic tocs and piro flips for the most part since i was in a kind of small field for the X5 i did not notice any bogging at the end of the pack. and that would have been with out the correct amount of head room pack came down at 3.77 per cell,

hopefully it wont be to cold for a test flight tomorrow, the weather here is up and down up and down, but usually it around 10o this time of year, not in the 30's and 40s

i appreciate all the help with the gov.

[Harrow]

Okay guys, if you're not interested in the maths, and don't want to look at a governor curve, then this is all you need to know if you are running the stock Gaui ESC and Scorpion 910 kV motor. Also, make sure you set the governor mode to GOV HIGH.

For optimal efficiency & performance, I believe that you should use the figures that are coloured orange. In other words, set your throttle to 72% or 73% and then choose a pinion to give the head speed that you want.

Using a lower throttle % and larger pinion to achieve the same head speed may result in decreased efficiency, choosing a higher throttle % and smaller pinion may increase the chance of bogging down for large stick inputs toward the end of the flight. Having said that, I expect that any of the values in this table will probably work fine.

Throttle . Motor rpm . Headroom . 13T . 14T . 15T . 16T
. 70% . . . . 15525 . . . . . . 23% . . 1682 1811 1941 2070
. 71% . . . . 16200 . . . . . . 20% . . 1755 1890 2025 2160
. 72% . . . . 16875 . . . . . . 16% . . 1828 1969 2109 2250
. 73% . . . . 17550 . . . . . . 13% . . 1901 2048 2194 2340
. 74% . . . . 18225 . . . . . . 10% . . 1974 2126 2278 2430
. 75% . . . . 18900 . . . . . . . 6% . . 2048 2205 2363 2520

Please note that these figures are based on my actual measured readings with my equipment, which is all stock, plus I am using a JR radio with DSM2 receiver. It is possible that there will be small variations in the precise throttle value between radios. My results are similar to, but do not match exactly to the published governor curve in the ESC instruction sheet. You should confirm your own setup with a tacho.

Your feedback is welcome, as I actually have no idea what I am talking about.

[dannylightning]

Awesome thanks

[vinnyd]

Originally Posted by Harrow

Okay guys, if you're not interested in the maths, and don't want to look at a governor curve, then this is all you need to know if you are running the stock Gaui ESC and Scorpion 910 kV motor. Also, make sure you set the governor mode to GOV HIGH.

For optimal efficiency & performance, I believe that you should use the figures that are coloured orange. In other words, set your throttle to 72% or 73% and then choose a pinion to give the head speed that you want.

Using a lower throttle % and larger pinion to achieve the same head speed may result in decreased efficiency, choosing a higher throttle % and smaller pinion may increase the chance of bogging down for large stick inputs toward the end of the flight. Having said that, I expect that any of the values in this table will probably work fine.

Throttle . Motor rpm . Headroom . 13T . 14T . 15T . 16T
. 70% . . . . 15525 . . . . . . 23% . . 1682 1811 1941 2070
. 71% . . . . 16200 . . . . . . 20% . . 1755 1890 2025 2160
. 72% . . . . 16875 . . . . . . 16% . . 1828 1969 2109 2250
. 73% . . . . 17550 . . . . . . 13% . . 1901 2048 2194 2340
. 74% . . . . 18225 . . . . . . 10% . . 1974 2126 2278 2430
. 75% . . . . 18900 . . . . . . . 6% . . 2048 2205 2363 2520

Please note that these figures are based on my actual measured readings with my equipment, which is all stock, plus I am using a JR radio with DSM2 receiver. It is possible that there will be small variations in the precise throttle value between radios. My results are similar to, but do not match exactly to the published governor curve in the ESC instruction sheet. You should confirm your own setup with a tacho.

Your feedback is welcome, as I actually have no idea what I am talking about.

This is what I love about this place! Thanks for the info Harrow.

Sent from my SCH-I510 using Tapatalk

[P.I.Engineer]

there's also a governor calculator at the hobbywing website that will do all that for you.

[Harrow]

Originally Posted by jrod155

there's also a governor calculator at the hobbywing website that will do all that for you.

I couldn't find it. Do you have a link?

[vinnyd]

Originally Posted by Harrow

I couldn't find it. Do you have a link?

Same here

Sent from my SCH-I510 using Tapatalk

[Harrow]

Well, I finally got to do some proper large field flying using the stock governor. My 15T pinion is still in the mail, so I was running the 16T on 71% throttle (gov high mode), which gives 2160 rpm. I'm still building confidence getting some stick time so it was only FFF and stall turns, etc. getting used to the large heli dynamics. It can sure eat up some ground fast when you stretch it's legs.

I flew 6 minutes, and came down with 3.83volts/cell. (Turnigy 4000mAh 40C)

When the 15T arrives, I plan to run 73% throttle (2194rpm).

It seemed to work quite well, and it was so nice to have the same head speed at the end of a flight as at the beginning. I will never go back!!

Danny, I expect you're going to like it once you get it all sorted.