Help Needed: Cracking the Code on LinuxCNC Servo Homing Setup!

More
2 years 4 months ago #303051 by eduard
I need your assistance with the homing process as I seem to be stuck. I have thoroughly reviewed the documentation and forums, but I cannot find the solution, and I do not understand why it is not working.This is not the first CNC I have built, but it is the first with LinuxCNC. The concepts of soft and hard limits are clear to me, but I do not understand their configuration and cannot achieve what I want. My goal is to home all axes to 0,0,0 using the servo's internal homing system, which then passes the coordinates to LinuxCNC. This part is working.Here's the process I want to achieve:
  • The machine should move within the specified hard limits when it is not homed. This is not working.
  • All axes should home during the homing process. This is working.
  • After homing, the machine should return with a 5mm offset where the soft limit starts. This is not working. 
    • HOME_OFFSET = 5 not working. 
  • The soft limit should be 5mm less than the hard limit on all axes. This is not working.

    Really hard to understad what is the linuxcnc's theory behind softlimits. Hardlimits are clar, working as expected. 
Attached are the INI and HAL files.

Please Log in or Create an account to join the conversation.

More
2 years 4 months ago #303053 by tommylight
Point 1 can be made to work granted there are no tandem axis/joints, bit sure uf this has to be deleted or added under TRAJ in the ini file
kinematics = both
Or something similar, sorry on the phone.
Home offset is usually -5 as it is the exact switch location, and if you want the dro to show 0 after homing. This is for searching in negative direction, or when the home switches are at machine 0.0.

Please Log in or Create an account to join the conversation.

More
2 years 4 months ago #303054 by Aciera

The machine should move within the specified hard limits when it is not homed. This is not working.

If the machine is not homed the controller has no idea where an axis is so if you enable jogging before homing then the operator will be able to jog the machine into the limit switches.

After homing, the machine should return with a 5mm offset where the soft limit starts. This is not working. 
[*]HOME_OFFSET = 5 not working.


Have you tried:
Code:
HOME = 5.00 HOME_OFFSET = 0.00 HOME_SEQUENCE = 1 # 0 Absolute encoder, joint does not use an absolute encoder # 1 Absolute encoder, final move to [JOINT_n]HOME # 2 Absolute encoder, NO final move to [JOINT_n]HOME HOME_ABSOLUTE_ENCODER = 1

Please Log in or Create an account to join the conversation.

More
2 years 4 months ago #303057 by Aciera

Point 1 can be made to work granted there are no tandem axis/joints, bit sure uf this has to be deleted or added under TRAJ in the ini file
kinematics = both

We need to make a distinction between jogging before homing and jogging in joint mode after homing.
The following user(s) said Thank You: tommylight

Please Log in or Create an account to join the conversation.

More
2 years 4 months ago #303061 by tommylight
LinuxCNC can and will jog before homing, at least it always did, or did something change that i am not aware of ?
ONLY tandem axis will not jog before homing, and even that can be bypassed by removing kinstype=BOTH in the TRAJ section.
Just in case this has changed, i am strongly against it.

Please Log in or Create an account to join the conversation.

More
2 years 4 months ago #303063 by eduard
Thanks,
The first point if fair enough, so I have to disable jogging while it is not homed.
On the second point, Yes, I tried the exact setup, just HOME_ABSOLUTE_ENCODER = 1, since the modified homing will move all the axis, and when it is homed, I need homing without movement. But after the homing, soflt limix reaching kicks in. I dont really understand why, and how soflt limits working in this exact situation.
From manual is clear, the AXES_n are used after the machine homed, and JOINT_n before, in joint mode. But where are the soflimits then?

Please Log in or Create an account to join the conversation.

Time to create page: 0.156 seconds
Powered by Kunena Forum