Centroid Community CNC Support Forum

AASD AC servo driver (Chinese driver)

Hey there I would love some help in this matter.

I have a DIY fiber laser machine that ive build with the acorn board.
Until recently all of my motors we're steppers hybrid servos(close loop steppers) they worked perfectly fine but I wanted more Speed and less vibrations, so I replaced all my motors and drivers with a Chinese ac 1kw servos and the drivers are AASD 20A ac drivers.
I've connected everything and all the axis are moving correctly but I'm having some issues with the position/accuracy/motor over shooting.. those are the stuff that I've come up with and thought about.

Those are the settings that ive set my drivers to :

Pn001 - 9 (motor code)
Pn002 - 2 (location mode)
Pn003 - 1 (servo enable)
Pn098 - 1 (10000 ppr)

Some people suggest that I will try to increase the pn115 and pn116 default settings from 100 to 500, but it didn't solve the issue.

To test where is the problem I've put the same settings in wizard as I had previously with my steppers.
Same max speed, same acceleration and everything.
The problem was still there.
With my steppers there wasn't any issue like this even though they are also Chinese and they made the machine frame vibrate alot more.
I've also tried so slow down the acceleration in wizard.
I've changed the acceleration settings from 0.2 to 0.5 but it didn't made any difference.

I'm adding the drivers manual bellow and also some videos and Pics that shows my issue.

Hello Tamar,

I have not used those servos before but it might be a matter of more tuning required if the mechanical aspects of the axes are solid. Did you do the automatic gain adjustment and inertia identification? Is it set for manual tuning (Pn258 = 0)? Pn115 and Pn116 will have no effect if Pn258 is set to 1 for automatic gain adjustment.

Is Pn109 still set to 0?

What is your setting for Pn113? If it is not oscillating then adding some position feedforward gain could help adjust for position error.

this is always the issue with the very cheap china servos, Tuning is a lot of work and sometimes impossible.

‏hey guys so here is an update on the Chinese servos.
i've tried a lot of settings with the servo drivers but the only settings that i found compatible with my system and mechanical frame and with the copy avids 3.25 : 1 reducers.
the only parmeters that were able to work Without having too much vibrations or position overlapping or overshooting.
I've tried a lot of different parameters
I've tried a lot of different parameters that are mentioned in the manual like the manual gain option, but I wasn't able to make it work without having too much of the vibrations. There is a vibration suppression parameter, but I wasn't able to make it work. At least it wasn't noticeable.
I am pretty sure that with a bigger gear reduction ratio like 1:5 or 1:10 the Chinese servos will be alot easier to use and will operate a lot better and smoother.
if anyone has more suggestions on how to improve their preferences, like less vibrations i would love to hear.

Z axis
Pn001 - 00001
Pn257 - 002.80 (axis inertia measured by fn018)
Pn003 - 00001(motor enable)
Pn097 - 00001(motor direction)
Pn259 - 00006(responsiveness)
Pn258 - 00001
Pn260 - 00001
Pn267 - 001.30(rated torque)
Pn271 - 03000(max speed)
Pn268 - 003.80(max torque)
Pn113 - 00100
Pn098 - 00001

X axis
Pn001 - 00009
Pn257 - 003.40 (measured by fn018)
Pn003 - 00001
Pn097 - 00001
Pn259 - 00004
Pn258 - 00001
Pn260 - 00001
Pn267 - 004.00
Pn271 - 02500
Pn268 - 012.00
Pn113 - 00100
Pn098 - 00001

Y1 axis
Pn001 - 00009
Pn257 - 006.50 (measured by fn018)
Pn003 - 00001
Pn097 - 00000
Pn259 - 00004
Pn258 - 00001
Pn260 - 00001
Pn267 - 004.00
Pn271 - 02500
Pn268 - 012.00
Pn113 - 00100
Pn098 - 00001

y2 axis
Pn001 - 00009
Pn257 - 006.50 (measured by fn018)
Pn003 - 00001
Pn097 - 00001
Pn259 - 00004
Pn258 - 00001
Pn260 - 00001
Pn267 - 004.00
Pn271 - 02500
Pn268 - 012.00
Pn113 - 00100
Pn098 - 00001



Y3 axis
Pn001 - 00009
Pn257 - 001.80 (measured by fn018)
Pn003 - 00001
Pn097 - 00001
Pn259 - 00004
Pn258 - 00001
Pn260 - 00001
Pn267 - 004.00
Pn271 - 02500
Pn268 - 012.00
Pn113 - 00100
Pn98 - 00001



B2 axis
Pn001 - 00009
Pn257 - 001.60 (measured by fn018)
Pn003 - 00001
Pn097 - 00000
Pn259 - 00004
Pn258 - 00001
Pn260 - 00001
Pn267 - 004.00
Pn271 - 02500
Pn268 - 012.00
Pn113 - 00100
Pn098 - 00001

Hey guys here is an update on the laser.
It's now with 1:5 planetary gear reducers which helps alot with the Chinese motor. They are operating alot smoother now.

I will akso try with a 1:10 reducers in the close future.
I really believe that the servos will work great with them.