Advanced Search

Yeah but someone starts a topic mentioning half a nanometre it's going to raise some interest. It's getting around to the level of the CMM NIST has in the US.
Precision is interesting whether it's a machinist hitting tenths on a manual lathe, a grader operator nailing a sub roadbed to the millimetre, the construction of the bridge over the harbour in the capital of my state or the work of Brunel in the 1800s.

Could StepGen be used to convert the absolute position data from the Fanuc encoder channels to quadrature pulses for outputting to encoder input on the drives? 

Cincinnati sabre 500. A simple 3 axis machine. The tool changer pivots on two hinges to swing the carousel under the spindle. It's resembles an arm bring a glass to a mouth.

Hi,
Thanks for your file. Please confirm if it contains the input pins information for 5 Axis BOB.
If not, please add the same.

If the resolvers connect to the drives (expected with AC servos) ,
a 7I49 is not needed (or useful)

Yes, assuming:

Black is out
Blue is ground = 24V common
Brown is +24V

7I95T firmware for 5ABOB but with added stepgen on pins 1,14
(so 12 total)

 
 

Leo75Wolf wrote:

Is there a way to change that to double precision floats (64bit) without having to rewrite the whole control?
 

This is his original question, that we did not answer, so he is right.
While waiting for someone that can answer that, you might want to have a look at the source code, it is on github:
github.com/LinuxCNC/linuxcnc
Also, these might or might not help:
forum.linuxcnc.org/38-general-linuxcnc-q...ming-milling-machine
forum.linuxcnc.org/38-general-linuxcnc-q...cision-home-switches

Hello Rodw,

I tried offset concept with the current system, but at the end fallback to the same thing happening previously. 

I have added the hal files and opratated the system, when start eoffset and changing the accelaration the accelaration changes only on Z axis level offset movement only, but this did not affect the possible speed variation on the other axis, can be increase or decreased.

also modified (attached) the eoffset hal file and xml file to set the acceleration dynamically but the reasult the small files get buffered in the queue by emctaskplan calls and the velocity/accel change commands never get executed, also shared the log file..
 

I have been using a very old Plasmac version from 2019 and although I alway planned to upgrade it, it just worked so got put off. A month or so ago I turned on my plasma only to find the hard drive had failed. I fitted a new ssd and did a build of QtPlasmac with Debian 12 bookworm. Although I got the machine working as such, I have a couple of issues that I am stuck on;

Using the same PC I used previously without issue, I now regularly get errors like 

“Mon24 13:59: Unexpected realtime delay on task 0 with period 1500000
This Message will only display once per session.
Run the Latency Test and resolve before continuing.
Mon24 13:59: hm2/hm2_7i76e.0: Watchdog has bit! (set the .has-bit pin to False to resume)
Mon24 13:59: hm2/hm2_7i76e.0: Smart Serial port 0: DoIt not cleared from previous servo thread. Servo thread rate probably too fast. This message will not be repeated, but the hm2_7i76e.0.sserial.0.fault-count pin will indicate if this is happening frequently.”

I have tried the period setting at 1000000, 1500000, 2000000 etc latency test is around 35000. 



the other major issue is that I can’t cut anything that has an arc unless I use the QtPlasmac conversational. My sheetcam produced code just generates errors like

--- QtVCP Screen Started on: Mon, Feb 24 2025 13:12:29 ---
--- CNC_Plasma - QtPlasmaC v2.9-236.301, powered by QtVCP and LinuxCNC ---
Mon24 13:12: Tool 0: No Tool
Mon24 13:14: Loaded: /home/darren/linuxcnc/nc_files/examples/Darrens Gcode Files/Motor Moutn Blue Mill/10mm motor plate Arc Lead (SMM).ngc
Mon24 13:14: G-Code error in 10mm motor plate Arc Lead (SMM).ngc
Near line 42 of
/tmp/emcflt-m50pkakv.d/10mm motor plate Arc Lead (SMM).ngc
Radius to end of arc differs from radius to start: start=(X31.0695,Y19.2947) center=(X29.4735,Y20.3617) end=(X29.6980,Y20.4360) r1=1.9198 r2=0.2365 abs_err=1.683 rel_err=87.6824%

I have ensured G91.1 is active and all the holes entries are # out in the nc file. 

Can anyone point me in the right direction? I can provide any extra info needed


 

using the python interface for on the fly feedrate changes is a bad idea that is what the real time 'motion' pins are for:
linuxcnc.org/docs/html/man/man9/motion.9.html

Did you try with the drive disconnected?

That is measure TB3 pin 4 (AOUT0) relative to TB3 pin 3 (GND)
with the 4 pin connector unplugged.