Limit an Axis or part of Machine travel to specific tasks possible?

Hello,

first of all, sorry if my english is not great, also it is very late now and i am tired. Also i havent found similar posts.

i may want to build a cnc machine with an atc at a specific place (on the far left side in X) but i want to limit a part of the x travel so i cannot accidently jog the machine to that position or if i run a program it will stop on the edge to that part of the travel because there may be a door in the way it should work like the toolchanger of a Hermle c600, but just on the left side (just need to limit one axis). Watch the example here:

for short: must not manually jog to that part of X travel, nor run gcode to that part. Only if a toolchange is commanded

thanks for any help

probably there's a better way, but i did that by modifying the soft-limit in tool change routine:


and from the change.ngc

Thank you very much!

Another way to do this is with a dummy axis. Use the U axis (for example) and add the U and X together before sending to the stepgen or PID. Then A G53 X0 followed by a G54 U0 will move into the forbidden zone.

probably there's a better way, but i did that by modifying the soft-limit in tool change routine:

net enable-toolchange-area <= motion.digital-out-10

loadrt mux2 names=ymax-mux
addf ymax-mux servo-thread

setp ymax-mux.in0 [AXIS_1]MAX_LIMIT
setp ymax-mux.in1 [AXIS_1]MAX_LIMIT_TOOLCHANGE ; extended area
net enable-toolchange-area => ymax-mux.sel
net y-limit-max ymax-mux.out => ini.1.max_limit

and from the change.ngc

M64 P10 ; enable off-limits movement
; move the spindle to the tool change area
; ...
; move out
M65 P10 ; restore the original soft limit

i tried it now, added the extended area to the ini and changed everything to "x min" but linuxcnc says Pin 'ini.1.min_limit' does not exist. i also changed ini.1.min_limit to ini.0.min_limit in case thats the axis but its the same

hm. in 2.7.11 it's there:

$ halcmd show pin ini.0 | grep limit
16 float IN 370.1 ini.0.max_limit
16 float IN -0.1 ini.0.min_limit

when i start linuxcnc without the extended limit and use halcmd i also see those pins. is there something i have to add like FEATURES = 30 if i want to read the ini pins?

says Pin 'ini.1.min_limit' does not exist

Ref (master branch):
linuxcnc.org/docs/master/html/man/man1/milltask.1.html


Note also:

ah okay that was my error, added it in my postgui.hal file and now it works.

Thank you!

Rather than having a mux2 in HAL and driving it from G-code it might be simpler to use a custom M-code to set the INI limits.

linuxcnc.org/docs/2.7/html/gcode/m-code.html#mcode:m100-m199

(I am not sure how to read INI values in bash, so you could either hard-code in the scripts or pass parameters from G-code.
Lots of possible ways are shown here: stackoverflow.com/questions/6318809/how-...ithin-a-shell-script )