Lichuan 4 axis stepper need help-

Hakan wrote:

Are the settings only possible through their software?
There are no SDOs for setting such things? Like Rtelligent has?

Yes there is. I will load the sdo docs on my NAS later, Seems like the app gives you access to all the SDOs and you can save them to a text file for later reimport so if you had a few of these drives it would be easy. The sdo docs sometimes have a better description.  You could make these settings from the command line using the ethercat app without putting in your XML. They show as bring Read/Write so hopefully they can be accessed when homing.eg reduce motor power when homing

So I had this theory that at default 10000 steps/rev it was running out of bandwidth when it got to 2000 mm/min (400 rpm). S0 I changed the steps to 1000 steps/rev which I assumed might get me to 10 x 2000 = 20000 mm/min
This let me get up to 8500 mm/min maximum velocity. But It did not get me to the expected 20000 mm/min (10 x 2000)
So definitely reduce the steps/rev if top end speed is important to you. I think you'll need to tweak the steps/rev to suit your design parameters.

If the drive is reducing the speed by itself you will get following errors.
Otherwise it's the settings in the ini file that are throttling the speed.

Hakan wrote:

If the drive is reducing the speed by itself you will get following errors.
Otherwise it's the settings in the ini file that are throttling the speed.

Yeh, that's what I have been playing with to determine where to set max velocity. I remembered from when I set up my plasma on a Mesa card to see how much of its 10 Mhz bandwidth I could use that there was a physical limit to how fast you could step in the real world. That's why I cut back the settings here. The design target was 10240mm/min so it fell a bit short, But the RPM is still quite respectable. I've had enough for one night.

I also might try increasing the amps a bit too

I doubt it uses step/dir internally. With a built in driver it most likely
skips that and energizes the coils more directly.
At last that's what I would do.
And then it keeps the count just as a way to determine position,
but not connected to a performance parameter.

Hakan wrote:

Its definitely a performance parameter for this drive. Maybe it isn't on their matched motors. NWE can confirm on his mother's eventually.
But you have given me a thought. If I changed parameters that I expected to get max velocity from 2000 m/m to 20000 mm/min and only got 8500 mm/min, I should be able to increase the step count from 1000 now without loosing performance.

Another thought I had which we can't do on this drive is on those machines with a torque reduction pdo, we could replicate what my step boost component does which is to reduce the torque (well curent in that case) when the motor is not accellerating to allow the motor to cool when not working hard. I used 50% current reduction but the maths indicates you can go a lot lower perhaps as low as 10-15%) This gives a massive performance improvement