Servo tuning

[Corpze]

Hi, i am just wondering when you guys are happy with your servo tuning, when the motors are quiet and runs good, or do you tune the settings to a certain curve?

/Daniel

[lukepower]

Well, I am happy when:

• I get no motor errors
• the tracking runs smoothly and quickly gets to where it should

It's all a matter off stiff mechanics (everything which could move, even slightly, makes things worse) and speed. WIth my 120kgs of equipment, I had to relax a few settings, especially the acceleration, to keep things balanced and currents low enough...

[MarkS]

For tracking, I look at the graph during manual tuning, and I like to see the trace within +/- .11 after settling, and a fast settle time with no oscillations.

 

For slewing, I like to see no oscillations. If I hear any buzzing I back the settings off. In Sequence I allow a 6sec settle time after slew.

 

For what it's worth, here are my settings for DDM60 for both ASA10N and OS130 telescopes and STT 8300FW8 camera:

 

Tracking: RA: D=1580; I=84000; P=17.5; NF on: cut-off 300: dampening 2

                DE: D=1580; I=100000; P=19.5; NF 0n: cut-off 300; dampening 2

 

Slewing: RA: D=580; I=14000; P=4.7; NF on: cut-off 300; dampening 2

               DE: D=520; I=14000; P=4.7; NF on: cut-off 300; dampening 2

 

Mark

[Corpze]

Thanks for the input.

What are your opinion on a "fast" settling? Within 3sec? 5sec?

Is there a "recomended" trace level one should aim to be within?

[MarkS]

For tracking, my recollection is that the trace should settle within a second  - but that is testing my memory   I'll check it next time I set up.

 

Mark