Z axis jog moves spindle only incrementally

Thanks for previous help but I am lost again and even thought I had sent this problem in but see no record of it on My Topics list.

I had to start over on this machine due to a complete computer crash and some other problems but at least the help given me before let me avoid some of the problems as this time I set it up with gantrykins so it went fairly well.
The machine is a gantry with xylotex hardware. It is up and running with limit switches on all axes. After I got it all running, I wrote a small program (attached, firstone.ngc) which was to try movement on all axes and it worked fine. Then I wrote another (new8.ngc) one try canned cycles and found that I could not make the Z axis feed in the correct direction. I could not get the program to work any way so decided to reverse the axis polarity. Note that the X and Y axes have their home switches on the negative end and the Z axis switch is now on the positive end.
At that point, there were all sorts of problems. FOr example. homing was in the wrong direction, which I corrected by changing the sign on the Home Search Velocity and inverted the feed direction but then the axis did not want to jog. I tried changing the table travel signs to no avail. All the setup to this point had been done with Stepconf.
This morning I edited (with gedit) the gantry.ini file and noted that the Max Limit on Z was only 0.1. I changed that to 8.0 and then the axis would jog, but homing did not work properly; that is, when Home All was chosen, only Z homed. And there were other quirks, So I went back to Stepconf and saved things and the .ini and .hal attached are from after that.

Thanks in advance for any help you can give me.

noted that the Max Limit on Z was only 0.1. I changed that to 8.0

It would be more common to have the Z axis home at 0.
In which case if there is 8" of travel on your Z axis the range would be 0 to -8.

Rick G

Rick,

Thank you very much for your reply.
I am not certain if I understand your first point about the homing at 0. All axes are homed at zero, but the X and Y home at the negative end as I understand it as when I jog away from home the positive jog is used and in G code programs positive numbers are used to move away from home. Conversely, the Z axis homes at the positive end as the negative jog button moves the spindle away from home and in G code negative numbers are used to move the spindle away from home
One thing that is confusing is that if I put those numbers into Stepconf, it does not change the numbers in gantry.ini. That is one reason that I finally resorted to direct edits of the file. I just tried it again and the values in stepconf are 0.0 and -8.0 but that is not what is written in the .ini files. Probably I am doing something wrong.
However, when I edited the gantry.ini file with gedit and changed the Axis 2 MIN_LIMIT to 0.0 and the MAX_LIMIT to -8.0.
The axes home properly but the Z axis gives "Can't jog joint 2 further past min. soft limit (or, alternately max) when the other jog direction is tried.
I do appreciate your help as it certainly confuses me.
Latest gantry.ini attached

changed the Axis 2 MIN_LIMIT to 0.0 and the MAX_LIMIT to -8.0.
The axes home properly but the Z axis gives "Can't jog joint 2 further past min. soft limit

O.K. using gedit on the z axis changeto
and try that.

Rick G

The max limit must be > min limit.

Yup, should have had my coffee first.
I have found that setting the max limit slightly beyond the home position (.01 instead of 0.00) sometimes prevents the soft limit error.

Rick G

[quote=I have found that setting the max limit slightly beyond the home position (.01 instead of 0.00) sometimes prevents the soft limit error.
/quote]
That is a good tip! Gotta try that on my machine!
Thanks!
/Chris

I was called away and just back to see several answers to my problem. So I thank you for all the comments and suggestions.

I will again attach the .ini file. I tried the suggestions and made several changes to what was suggested. probably in error, but now the Z axis moves in the right direction (minus direction is down) and the homing direction is up (in the plus direction).
The limit switch on this axis is on the plus end is also the home switch. So the spindle carriage moves up and strikes the home/limit switch and that is good. The directional problems from before seem to be okay though I have not tried to run a program.
However, when it strikes the home/limit switch there is an immediate error "joint 2 on limit switch error". I tried replacing that limit switch thinking maybe of bounce or other fault and that did no good. I tried editing the minimum limit in the .ini file but could not hit on anything that would work. Also, after the error occurs, I have manually moved the axis down and it clears the error, but the GUI shows that the movement is in the plus direction and then the axis jogs downward with the negative button but stops when it reaches the reading -0.01which is the soft limit. Obviously I am a long way from understanding the interplay of the various parameters/
If I had any wits, I would be at the end of them.

I thank you again for your past help and hope that you can help me out again.

Looks like "HOME_IGNORE_LIMITS" is already selected.

Have you seen this?
linuxcnc.org/docs/html/config/ini-homing.html

You have...
Try...
[AXIS_2]
TYPE = LINEAR
HOME = 0.0
MAX_VELOCITY = 2.85001824012
MAX_ACCELERATION = 30.0
STEPGEN_MAXACCEL = 37.5
SCALE = 6400.0
FERROR = 0.05
MIN_FERROR = 0.01
MIN_LIMIT = -8.00
MAX_LIMIT = 0.00
HOME_OFFSET = 0.000000
HOME_SEARCH_VEL = 0.300000
HOME_LATCH_VEL = -0.078125
HOME_IGNORE_LIMITS = YES
HOME_SEQUENCE = 2

Rick G