Hello Guest it is December 14, 2019, 12:53:30 PM

Author Topic: Continual issue of Z zero being automatcially changed.  (Read 1560 times)

0 Members and 1 Guest are viewing this topic.

Re: Continual issue of Z zero being automatcially changed.
« Reply #10 on: April 29, 2018, 02:40:54 PM »
Hi,
I think it has to do with this line:

Quote
N15 G43 Z0.925 H4

The H4 is applying tool length compensation. Try removing the 'H4' and see how it works.

Craig
My wife left with my best friend...
     and I miss him!
Re: Continual issue of Z zero being automatcially changed.
« Reply #11 on: April 29, 2018, 02:58:09 PM »
Hi,

Quote
G43/G44 – Tool Length Offset: Activates a tool length offset selected with H. When activated the position DROs will be updated to display the position of the program point of the tool, generally the tip. The tool offset can be applied in the positive direction with G43 or in the negative direction with G44. Generally G43 will be used to apply the tool offset. There are a number of ways of touching off a tool and determining the offset value, see tool offsets in the operation manual for more details, but they are all called and applied the same way.
Format: G43 H__ X__ Y__ Z__
If axis positions are specified in the same block as G43 the machine will move to the commanded point. If the axes are omitted there will be no motion.

Craig
My wife left with my best friend...
     and I miss him!
Re: Continual issue of Z zero being automatcially changed.
« Reply #12 on: April 30, 2018, 01:19:08 PM »
Hi Craig,

   I think you are on to something! Totally makes sense. I've done some searching based on what you mentioned and found a forum thread that outlines my exact issue. It provides the required post processor modification!

Going to make this change and see if it provides an end to my zeroing woes.

Thanks so much. I'll let you know how it goes!

https://forums.autodesk.com/t5/fusion-360-computer-aided/mach3-how-to-i-remove-g43-from-post/td-p/7168904
Taig Micro Mill. 1/4-20" lead screw. Powered by 1.25hp router with a 4:1 pulley reduction. Driven by Ethernet SmoothStepper to a Gecko 6540. Nema 23 motors. 3 Axis.
Re: Continual issue of Z zero being automatcially changed.
« Reply #13 on: April 30, 2018, 02:42:29 PM »
Hi,
does your machine have an ATC? Tool Length settings make sense and are required for ATC but if you are manually fitting tools then you need to touch off
at each tool change anyway,

Craig
My wife left with my best friend...
     and I miss him!
Re: Continual issue of Z zero being automatcially changed.
« Reply #14 on: April 30, 2018, 03:10:33 PM »
Hi,

  No, it doesn't have ATC. I manually change tools by opening the collet and then zeroing Z each time.

Thanks
Ben
Taig Micro Mill. 1/4-20" lead screw. Powered by 1.25hp router with a 4:1 pulley reduction. Driven by Ethernet SmoothStepper to a Gecko 6540. Nema 23 motors. 3 Axis.
Re: Continual issue of Z zero being automatcially changed.
« Reply #15 on: April 30, 2018, 07:43:44 PM »
Hi,
then the simple expedient is do away with the auto toolchange code.

I usually have separate job (Gcode files) for each tool I require, means that I have no M6 calls
anywhere...saves a lot of grief.

Craig
My wife left with my best friend...
     and I miss him!
Re: Continual issue of Z zero being automatcially changed.
« Reply #16 on: May 01, 2018, 10:36:33 AM »
Hi Craig,

   I also have been saving out separate files for each tool, and even each operation sometimes. Looks like I need to clean up my code and understand what it is doing on a deeper level. I've found a way to turn off all M6 and G43 commands. I've just completed a new enclosure for my cnc and will be testing soon. Thanks for all your help. It will be such a relief to not worry about my Z changing all the time!

Thanks,
Ben

Taig Micro Mill. 1/4-20" lead screw. Powered by 1.25hp router with a 4:1 pulley reduction. Driven by Ethernet SmoothStepper to a Gecko 6540. Nema 23 motors. 3 Axis.
Re: Continual issue of Z zero being automatcially changed.
« Reply #17 on: May 01, 2018, 01:11:33 PM »
Hi,
yes you need to be able to read Gcode to do any reasonable or informed CNCing. Welcome to the obsession!

Craig
My wife left with my best friend...
     and I miss him!