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LinuxCNC controls CNC machines. It can drive milling machines, lathes, 3d printers, laser cutters, plasma cutters, robot arms, hexapods, and more.
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PncConf make wrong Tandem Axis for first "HOME_SEQUENCE = -0" #2616

Closed zz912 closed 1 year ago

zz912 commented 1 year ago

RIP 2.9 Branche Debian Bookworm Oracle VM VirtualBox

Hello,

Maybe I'll make an interesting machine with "X Y1 Y2 Z1 Z2" kinematics. That's why I'm preparing for this situation. I made the configuration "X Y1 Y2 Z1 Z2" by PncConf. I used it to simulate this configuration. Here are configuration sim files: Z0069_sim-003.zip

The homing sequence must be: 1) Z 2) X 3) Y

This creates a situation where the INI file contains: HOME_SEQUENCE = -0 Minus zero is not my invention. This was invented by PncConf.

The bug is that I can break the CNC machine in joint mode. I can move the Z axes asynchronously. Asynchronous_Z1_Z2

Automatic homing works fine: automatic_homing

Manual homing is very, very dangerous, I can home: 1) Z1 2) Y1 and Y2 3) X 4) Z2 manual_homing

andypugh commented 1 year ago

-0 is valid in IEEE floating point. But .home_sequence is an int, so I agree that the setup wizard should not be using -0. (Or, possibly, should refuse to use 0 as the sequence number for a tandem joint. I haven't run a test to see how this happens)

zz912 commented 1 year ago

I looked in the documentation: http://linuxcnc.org/docs/2.9/html/config/ini-homing.html#sec:homing-section

The initial HOME_SEQUENCE number may be 0, 1 (or -1).

This is NOT bug of motion, but this is a bug of PncConf.

Correct solution for my exmple is: [JOINT_0]HOME_SEQUENCE = 2 [JOINT_1]HOME_SEQUENCE = -3 [JOINT_2]HOME_SEQUENCE = -3 [JOINT_3]HOME_SEQUENCE = -1 [JOINT_4]HOME_SEQUENCE = -1

This works correct.

zz912 commented 1 year ago

https://github.com/LinuxCNC/linuxcnc/pull/2660 covers this problem.