Hybrid View
-
29-02-2020 #1
Hi Nick,
Here's those way covers I was talking about, pictures didn't do it justice so a little video shows it better. Hope it helps
-
02-03-2020 #2
Ah thank you very much, I see what you mean now, those look great, really simple design, just sheet metal and a few welds. I will give making some a go.
Following error wise. What speed are you aiming for? How have you found tuning the internal PI loops? I'm struggling to tune the servos. I'm just about at less than 10 microns f-error now on the X and Y, I am cheating slightly acceleration dropped a bit, speed reduced to 1500mm/m. I think my main issue is the servo speed and torque loops aren't tuned. The error got a lot better when I put in the inertia load into Pn257 after I ran the Fn018 mode to get the inertia ratio. I'm using gain adjustment mode 1 (Pn258) and then adjusting the "rigid grade selection" until I get oscillations / vibration. I found the linuxCNC tune very sensitive to FF1
I haven't worked out how to properly tune the internal PI's because I can't work out how to bring linuxCNC into open loop and then command a specific speed in LinuxCNC. I am thinking about using the internal speed command function and toggling this with push buttons. Say set it to 250, -250rpm and then I will be able to jog it back and fourth while looking at the HAL scope.
-
02-03-2020 #3I haven't worked out how to properly tune the internal PI's because I can't work out how to bring linuxCNC into open loop and then command a specific speed in LinuxCNC. I am thinking about using the internal speed command function and toggling this with push buttons. Say set it to 250, -250rpm and then I will be able to jog it back and fourth while looking at the HAL scope.
https://forum.linuxcnc.org/10-advanc...etailed-how-to
I am in the same boat as you and struggling with a following error when using closed loop. Changing closed to open loop is just one change in the hal file.
This is also my first time with halscope..Clive
The more you know, The better you know, How little you know
-
02-03-2020 #4
Yeah, that's what i've been following, really useful. I also found the John Thornton guide's. Using speed mode, via a mesa 7i77, so linuxCNC is running the position loop.
I will try torque at some point I think. I'm sure the issue is with the drive speed and torque PI loops. How have you gotten on with setting the drive PI settings? I'f i put it in open loop I think the axis will drift and I don't think I could command an analog signal? or maybe I could?
-
02-03-2020 #5
Nick, Clive is using Step & Dir Mesa card not Analog +/-10v using Position mode in the drive. He's using the same AASD Drive as you but 30A with 1.8Kw servo.
-
02-03-2020 #6
Thread Information
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
Similar Threads
-
Where to start? Vertical Mill CNC conversion.
By Richard in forum Milling Machines, Builds & ConversionsReplies: 8Last Post: 26-09-2021, 03:11 PM -
WANTED: Harrison mill Vertical head
By D-man in forum Items WantedReplies: 0Last Post: 18-06-2016, 01:43 PM -
Epoxy granite or mineral casting
By mike mcdermid in forum Gantry/Router Machines & BuildingReplies: 46Last Post: 20-02-2014, 06:21 PM -
Epoxy Granite Molds?
By gavztheouch in forum Moulding MachinesReplies: 8Last Post: 18-02-2014, 07:28 PM -
BUILD LOG: Vertical fixed gantry. Design & build. (Steel/epoxy)
By Greeny in forum DIY Router Build LogsReplies: 8Last Post: 19-08-2013, 08:26 PM
Bookmarks