Robot Homing Issue

I have a vismach sim of my hobby robot working with Axis GUI.  I'm having an issue with the homing the real robot. Both are using the same modified DH parameters.

I plan to only use witness marks to home the robot, no home or limit switches.  So Home_All should have no motion and just assume the arm is positioned at the witness marks. 

The problem is when I setup homing so there is no motion the kinematics are off and an error is generated. The cartesin XYZabc is wrong.

When I use the HOME = -90 position for axis 2 the shoulder, from the sim, the kinematics are correct but it cause the robot to move even though HOME_SEARCH_VEL = 0 and HOME_LATCH_VEL = 0.

Is what I'm trying to do possible?

 

Aciera post=311433 userid=25994Try:

HOME_OFFSET = 90.0
https://linuxcnc.org/docs/html/config/ini-homing.html#_home

Whoa, that was dicey, almost put the arm through the window.  It seemed like the HOME and _OFFSETT were cumulative with those settings ~180 degrees searching home.

After trial and error I think I have it working with both HOME_OFFSET and HOME set to the same value 90 & 90 or -90 & -90 depending on the specific axis.