4525 with Commander V fluctuating RPM

[nicholsen]

Hi,

I hope someone can give me some input for the following problem.

I've just finished my Goblin build and been test flying the setup yesterday.
I'm running the Commanders internal governor mode with flat curves at 70% and 90%.
The problem is that I get sudden fluctuations in the rpm a few times every minute for no apparent reason. The rpm will jump a few hundred rpm up, stay there for 5-10sec then come back down to the original speed. The heli gives a tiny wriggle every time in response so it's a fairly fast rpm change.
All this happens with no input on the sticks in a steady hover as well as when maneuvering.

I'm running the 2 leads (throttle and extra BEC lead) from the ESC to my HC3-SX to power the servos at 7.4V.

Any suggestions and ideas greatly appreciated!
Thanks

[Matt Nasca]

Originally Posted by nicholsen

Hi,

I hope someone can give me some input for the following problem.

I've just finished my Goblin build and been test flying the setup yesterday.
I'm running the Commanders internal governor mode with flat curves at 70% and 90%.
The problem is that I get sudden fluctuations in the rpm a few times every minute for no apparent reason. The rpm will jump a few hundred rpm up, stay there for 5-10sec then come back down to the original speed. The heli gives a tiny wriggle every time in response so it's a fairly fast rpm change.
All this happens with no input on the sticks in a steady hover as well as when maneuvering.

I'm running the 2 leads (throttle and extra BEC lead) from the ESC to my HC3-SX to power the servos at 7.4V.

Any suggestions and ideas greatly appreciated!
Thanks

What do you have your P & I gain set to ?

[nicholsen]

P & I gain are at factory default value 5

[Matt Nasca]

Originally Posted by nicholsen

P & I gain are at factory default value 5

A couple hundred RPM is a ton!

hmmmm, that's puzzling! I'm not sure what that would be if not the following:

Flat line throttle not completely flat
H3C is trying to interfere/control the throttle. (I'm not familiar with the H3C-SX)

I would try re-calibrating the throttle on the ESC and re-setup the governor. If that doesn't do it, I'm not sure with the information I have. Hopefully Scorpion will chime in with an idea.

[nicholsen]

Thanks for the input Matt, will definitely try to re-setup. Funny thing is when I was building the Goblin I threw the Commander into my Trex 600 and noticed the same behavior. Since it was just a temporary thing I didnt do much setting up and didnt think more of it at the time. I have since set it up again when I put it in the Goblin but the issue persists.

As for the RPM change, Im not sure that its in the 100's as I was not using any tach. Just guestimating from the pitch of the sound...

[Stolla]

if you run at 90%, I can't see enough headroom, does it do the same at 70?

[nicholsen]

I havent used the 90% setting yet so not sure if it does it too.

So after a few re-setups its running much better, however i had 2 instances of RPM drops during the flights today (indicated by a chance in the sound from the blades) - Perfect pair of new underwear ruined! The drop lasts about 15-20 seconds before normal rpm resumes.

Anyone with similar experiences?

[sjsamuel]

Originally Posted by nicholsen

...Perfect pair of new underwear ruined!...
Anyone with similar experiences?

I have nothing worthwhile to add..this just cracked me up!! ? LOL!!

[Georges van Gansen]

Very Important!!: every time you change your setup on the helicopter such as new type of blade, new motor, new gear ratio, or using the ESC in other helicopter , you need to re setup the governor as our governor is load dependent, and will store the load calculations in the memory of the ESC.

Tips For Setting Up The Governor
To Program the ESC to optimize the RPM range, please follow the below
instruction:

- Make sure you have a fully charged flight pack.
- Program SS [2] on the Program card (Soft start with Governor Function).
- Spool up the helicopter to 50% throttle in fairly rapid movement (either engage the idle switch with a 50-50-50-50-50 curve or move throttle stick without hesitation)
- Stay at zero pitch, and leave the stick there until the LED on the ESC turn off.
- Stop the motor by either lowering the throttle stick or engage throttle hold.
- Wait 15 seconds for the governor RPM caculation finish and stored in the ESC memory.


The helicopter is now ready for flight where you can program your throttle curves as you wish. Remember that Governor do like _at curves as it has to re-acquire its RPM at each throttle change. A flat curve like 80-80-80-80-80 is required for idle-up where the actual percentage determine your head speed.

Please note: A motor that surges in hover is indication that above routine was not performance correctly.

Happy landing.
Georges

[nicholsen]

Thanks for the reply Georges,

the setup procedure you mention is the one I have been following, and it has eliminated the fluctuations I mention in my first post.

However the RPM drops I've seen on the last few flight seem to be of a different character (duration, pitch etc)

On my way out to fly shortly so will report back on how it goes.

[Georges van Gansen]

on my Goblin, i set the P gain to 9 and I gain to 7, all works really well.

[nicholsen]

It works great now. RPM is rock solid!

Georges, are you running a buffer pack on your setup?

[Georges van Gansen]

I do not run buffer pack on my test helis since I am trying to test ESC and make sure i can document every thing, but i do run a buffer pack on helis that i fly for fun.

Electronic components can fail, I will never trust any BEC system at 100%, a buffer pack is 100% sure to work in case of a component failure in the BEC system, I know it sound strange that some one making BEC system will say this, but it's my honest opinion.

[nicholsen]

Appreciate your honest opinion and I do agree.

I fly the A320 for a living, and its a highly automated 88 million dollar aircraft with tons of electronics and on-board computers. The reason I bring it up is that, believe it or not, the (noncritical!) failure of systems and components is a regular part of the operation.
It is said -jokingly- that the most used phrase by Airbus pilots are:
"Whats it doing now?"
and
"Ive never seen that before"

Most failures can be solved by a simple system reset or pulling and resetting a CB...anyhow... I digress!

So, yes...of course some failures can be anticipated in a $350 ESC. All the difference is made in how the company and its representatives deal with it, and I must give you and your company top marks in that category!

Thanks!

[IanWhitehead65]

Originally Posted by Georges van Gansen

Very Important!!: every time you change your setup on the helicopter such as new type of blade, new motor, new gear ratio, or using the ESC in other helicopter , you need to re setup the governor as our governor is load dependent, and will store the load calculations in the memory of the ESC.

Tips For Setting Up The Governor
To Program the ESC to optimize the RPM range, please follow the below
instruction:

- Make sure you have a fully charged flight pack.
- Program SS [2] on the Program card (Soft start with Governor Function).
- Spool up the helicopter to 50% throttle in fairly rapid movement (either engage the idle switch with a 50-50-50-50-50 curve or move throttle stick without hesitation)
- Stay at zero pitch, and leave the stick there until the LED on the ESC turn off.
- Stop the motor by either lowering the throttle stick or engage throttle hold.
- Wait 15 seconds for the governor RPM caculation finish and stored in the ESC memory.


The helicopter is now ready for flight where you can program your throttle curves as you wish. Remember that Governor do like _at curves as it has to re-acquire its RPM at each throttle change. A flat curve like 80-80-80-80-80 is required for idle-up where the actual percentage determine your head speed.

Please note: A motor that surges in hover is indication that above routine was not performance correctly.

Happy landing.
Georges

Hi Georges,

I have a commander 45A ESC and it does not have an LED. I read somewhere that the throttle with "blip" when the gov is initialised. Is this correct?

I have initialised gov twice now following SS2 and cannot get the gov to work consistently. I have been getting low and fluctuating (reducing) headspeed. No apparent tail and main wag. What sort of P & I gains would be good for a 3,700kv motor on a 450 heli?

The ESC works in all other respects as far as I can tell. Very happy with the ESC other than setting up the gov.

Your help would be most appreciated.


Thanks,

Ibs

[Georges van Gansen]

I will try P gain 9 and see dose the tail still hold, if not reduce P gain.
I gain can go as high as 8, if you get tail wag due to the governor, reduce it 1 at a time,
But make sure your tail servo and mechanics are very smooth and no slop or stiff spot
or high I gain will amplify a bad setup.

[IanWhitehead65]

Originally Posted by Georges van Gansen

I will try P gain 9 and see dose the tail still hold, if not reduce P gain.
I gain can go as high as 8, if you get tail wag due to the governor, reduce it 1 at a time,
But make sure your tail servo and mechanics are very smooth and no slop or stiff spot
or high I gain will amplify a bad setup.

Hi Georges,

Thank you very much. I will try over the weekend and see how I go.

Cheers,
Ibs

[IanWhitehead65]

Hi Georges,
Not very successful. The weather made it hard but I wonder if my esc is broken now. I have installed the IR receiver and set it to irp and the motor does the 4 Beeps indicating it is in programming mode. However, when I do ss2 there is no confirmation beep. I am making sure the programmer is pointing at the receiver and the leds at lighting but there is no beep. Pressing ss, 2, enter. Then I tried ss1 with the same result. Then gov, 8 and enter but again no confirmation beep.

Ignoring the beeps I spooled up the heli in iu at 50% and I got the throttle blip. Waited at least 30 seconds before pulling the plug. Then I adjusted my TC to 90% and flew. I don't have any experience with governors but I was happy with the head speed. However, the next flight the head speed was low and inconsistent. Tried to adjust p & I gains but no confirmation beep from the esc.

Is my esc or IR programmer broken or connected incorrectly. Am I programming wrong?

I am concerned that I can't set the esc back to ss1 now and therefore won't be able to use the esc.

Sent from my GT-I9100 using Tapatalk 2

[Georges van Gansen]

no confirmation mean it has not been programed, change the small battery of the IR remote and try again.

[IanWhitehead65]

Originally Posted by Georges van Gansen

no confirmation mean it has not been programed, change the small battery of the IR remote and try again.

Hi Georges,

I took the battery out and got 3.3V from it. It is only a week or two old so I would find it hard to believe the battery could need replacing.

In the quite and shade of my garage I was able to see and hear the ESC responding to the IR programmer. First thing I did was set SS1 and I got the confirmation beep. Set SS2 and got confirmation beep. Tried GOV8 and got no confirmation beep. Tried SB7 and got no confirmation beep. Gave up.

What is the sequence for setting up the GOV and the gains. For example.

1. SS2.
2. Initialisation run at 50% throttle.
3. Wait 12 seconds and disconnect battery.
4. Reconnect battery and program gains.
5. Fly.

Is this the correct sequence? Should the ESC beep when programming GOV or SB?


Thanks,

Ian