G28.1 assistance...

Davek0974 · Post by **Davek0974** » Fri Apr 11, 2014 9:45 am

I'm switching from G31 to G28.1 as I need to free up a board input used by the probe switch.

In the post I am using (THC with scriber) the G28.1 entry is thus

G28.1 Z3.0 F350

Where does the Z3.0 come from>
I presumed it would just probe until the limit trips?
With a 3.0 in there surely it wont probe all the way down.

Post by **Les Newell** » Fri Apr 11, 2014 10:34 am

If I remember correctly the 3 is hard coded. G28.1 will only stop when it hits the switch:

G28.1 Reference Axis

Program G28.1 X~ Y~ Z~ A~ B~ C~ to reference the given axes. The axes will move at the current feed rate towards the home switch(es), as defined by the Configuration. When the absolute machine coordinate reaches the value given by an axis word then the feed rate is set to that defined by Configure>Config Referencing. Provided the current absolute position is approximately correct, then this will give a soft stop onto the reference switch(es).

Davek0974 · Post by **Davek0974** » Fri Apr 11, 2014 2:42 pm

Yes, all is well and it works nicely.

Vmax549 · Post by **Vmax549** » Sat Apr 12, 2014 1:43 am

The Z3.000 is the go to point for the G28.1 . It will first go to Z3.00 then home to a switch .

(;-) TP

Davek0974 · Post by **Davek0974** » Sat Apr 12, 2014 7:04 am

Ok thanks

Davek0974 · Post by **Davek0974** » Sun Apr 13, 2014 4:21 pm

It's working but the dro does not reset correctly, it seems I need to use a macro to do the resetting and allow a delay thus...

G28.1 z3.00 f250 - probe the surface
Mxxx

The M Code would be something like:

Code "G92 z0"
While IsMoving()
Wend

Code "G00 z4"
While IsMoving()
Wend

Code "G92 z0"
While IsMoving()
Wend

Code "G00 z1"
While IsMoving()
Wend

How do you call a macro from a sheetcam post?

Davek0974 · Post by **Davek0974** » Sun Apr 13, 2014 5:57 pm

Thinking about it, a mach macro call will not worse cause the pierce height is set within sheetcam not mach3.

Surely there is a way to get G28.1 working properly??

Davek0974 · Post by **Davek0974** » Mon Apr 14, 2014 7:01 am

Its ok, it all works, somehow it was the M30 that upset things.

However, since changing to G28.1 when the post code reaches a goto-rapid-clearance height, the Z motor emits a loud screech and does not move, I cant see a reason in the code attached, can anyone have a look.

Davek0974 · Post by **Davek0974** » Mon Apr 14, 2014 11:55 am

All issues now resolved.