Problems with Lichuan Ethercat servo drive

They do seem to work. I've spent about 3 hrs tuning these so far. I'll have a hopefully final go next week. I've got 4 1kw servos (gantry). There are enough details in the manual to do the tuning. The velocity feed forward from Linux Cnc really helps with following error to a ramp, which is what I'm testing. I wish there was a way to restart communication without restarting the drives. It is tedious using the buttons on the drives. If I get a satisfactory procedure I'll write it up.

im gonna ttry and use them on my lathe retrofit. To see more info look here and feel free to ask some questions!

forum.linuxcnc.org/38-general-linuxcnc-q...ofitt-feeler-ftc-280

I just tuned my omron ethercat servos. I fear manual tuning on these lichuans, haha. How are you doing it, just scoping it in twincat or linuxcnc? or do they have an app?

Dont know if this help but I managed to tune the following error to around 20 micron at 3000mm/min. The drive is non ethercat, just regular step+dir. Tuning it was quite trivial. Turning speed forward gain to 100% should reduce the following error significantly

is that just on acceleration, or is that lag on a straight line?
what is is the acceleration?

20 microns if its only on high acceleration and speed is "a good starting point' i think. shows much promise.

for comparative reference

My JMC ihsv57's were tuned to about 6 or 8 microns, at 0.3g and 1800rpm (as fast as they would go)

My omron ethercat servos are now tuned to like 4 microns in in acceleration moves at 1G and 1 micron during constant speed.

Wow your numbers are impressive.
I have been under tuning my machines. The acceleration is around 0.1-0.2G. Since I only mill steel so no need for high speed and I can already feel my machine shake with that acceleration. I think it need jerk limit trajectory planner to unlock its full potential

Has anyone actually run these servos? I'm trying to tune these, which was going well. However I'm having an issue where the drives randomly develop an offset. Not following error. I can use the pendant and the same offset stays.  I can manually force the motor back and forth, and the offset stays. When I turn the drives off, and on, the offset dissapears. I put a dial on and the offset is real. The encoder is not loosing position, it seems to be something in the drive. Any ideas? Anyone seeing this? Anyone not? 

that's still very decent. my machine is "faster than most". yours is more in line with what most people will be doing with these servos i expect.

omron 200w servo. 1G, 3000rpm. (cant wait to get it to 5000rpm muhahhaha!


jmc motors in use. 0.3G, 12m/m (pulse limitation). The real issue with these is they are soft. like even though they track with feed forward, stiffness is so low that cutting forces push the axis off track by a thou or 2. Need to take a spring pass ore 2 for a precise cut.


My hope is that these lichuans will be a step well above the JMC but still "cheap and cheerful" for my production machines. Cause those omrons cost more than the machine frame
 

weiiird. is that mm for f error?
what axis?

Mine are omron, so no help there but when they stop, they are within 2 encoder counts (20 bit). I wonder if there is a feed forward thing where its just not bothering to catch up after stopping. I think i had that on my brother analogue servos when i chose some bad settings.


(also , side note, i need some help with ethercat setup, haha)