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Offsets and saving.
« on: March 27, 2011, 05:09:13 PM »
Hey guys.  I was wondering if there was a way to not save offsets for tools from cut to cut.

I'm using my mach 3 as if it has an ATC attached to it, but am manually changing bits using the general config cycle start for tool changes command.  It works like a champ and is so much simpler than trying to have a seperate G-code for each tool used.  I'm still a total newbie and am learning daily still.    The main problem I keep encountering is when I start mach 3 up for the day, I put in my tool and zero all my axis with this specific tool that I intend to use.  Then, I load my program up and cut away.  The problem I have is I never think to check for tool offsets with my first tool of the day or see a need to rezero the tool a second time.   When changing tools, it completely makes sense to have to enter the offset in, but Im on lesson #4 of first cuts.  Today it cost me 1/2"" into my spoilerboard and right through one of my T-Tracks in under 3 seconds.

Offline Hood

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Re: Offsets and saving.
« Reply #1 on: March 27, 2011, 05:16:15 PM »
Are you only ever using one tool in a programme? If so then no need to enter values into the tool table, just bring the tool down onto the top of your work and set the Z axis as Zero. If the tool table is blank then even if you call a height offset in your code then it will not change as all are zero offset.

Hood

Offline ger21

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Re: Offsets and saving.
« Reply #2 on: March 27, 2011, 06:22:05 PM »
Are you looking for something like this?

http://www.youtube.com/watch?v=7np99wSr9c8
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: Offsets and saving.
« Reply #3 on: March 27, 2011, 11:00:34 PM »
I guess I need to clarify my issue a bit.    :-\


I'm usually using multiple tools in a single program.  I understand that I have to adjust the offset of the tool every time I change a tool out in the offset menu (my first attempts including rezero'ing the DRO's about a month ago for every tool. Obviously I learned that quickly).   With how I have been using Mach 3 for about a month now I've gotten all of the basics figured out.  When I initially start mach 3 up, I set all of my DRO's to zero where my zero point should be with the first tool I intend to use in the spindle.  This way I am completely ready to cut when I load my gcode into mach 3.   I then load the program into mach 3, regenerate toolpath and do a jog follow around my workpiece watching the mach 3 screen to make sure my cutting area is where my workpiece is and that I'm not going to cut through a hold down.   After that, I click the start button and the program starts.  It runs down the initial G code until it gets to the point where my first tool is 'entered' into the program (as a tool changer would need to see).  Mach 3 halts the gcode, a yellow LED flashes signaling tool change.  From there, I always just click cycle start and start my program because I already have the tool in.   

I am running into issues if I used this particular tool in a previous program and set the offset up on it. For example, Tool 13 is the initial tool I am using and have setup everything for.  My program runs and gets to the point where it wants me to put in tool 13.  I click cycle start because its already in there and go about my business.   BUT, I have been running into issues if I used tool 13 ever before in any program and set the tool offset on it.  Mach 3 remembers this tool offset and it incorporates it right into the program ONLY after I've clicked cycle start to run the program again.  I forget to make sure there is no tool offset entered and this has caused me issues several times.  Its one of those redundancy things where I have to zero Z over and over and over again, so I tend to forget and skip this step.


  I am wanting to know if its possible to keep mach 3 from remembering previously entered offsets for tools after I shut it down.  As my machine is homemade and my tools are at different heights everytime I put each one in, they are never the same exactly.  So, everytime I change a tool out I have to do the offset anyways.  I just never expect that to apply to the first setup because I zero'd the tool already.


GER21- I've been looking at making an auto tool zero gauge block.  I actually posted about it when I was still researching on here a few months back.  I should have one made this week, but right now I am trying to prioritize and get some hard stops done so my gantry stays on the table when I'm stupid and get limit switches functioning.  I designed up mounting blocks for the limit switches over a month ago, I just havent cut them yet. 
« Last Edit: March 27, 2011, 11:02:45 PM by jtcdudeman »

Offline Tweakie.CNC

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Re: Offsets and saving.
« Reply #4 on: March 28, 2011, 04:00:33 AM »
Not sure if I am understanding this correctly but if you zero all your offsets (offsets page) then uncheck 'offset save' and 'persistent offsets' etc in General Config page then Mach will have no knowledge of previously used offsets when starting up again from scratch.

Tweakie.
PEACE

Offline Hood

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Re: Offsets and saving.
« Reply #5 on: March 28, 2011, 04:33:38 AM »
Tweakie
 Think the tool table offsets will still be saved, AFAIK these are for DROs.

jtcdudeman
Do yo use a toolholder system where you can set up tools all at once then run a programme or do you have to set each one up each time you put it into the spindle. If the latter then no need for tool table entries. If the former then the only way I think you could do it is have a macro that is called at startup to zero the DROs, let me know which and if the former I may be able to assist with the macro although I am not great at VB.
Hood

Offline Tweakie.CNC

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Re: Offsets and saving.
« Reply #6 on: March 28, 2011, 09:46:25 AM »
I think Hood is right and I am on the wrong track here but one thing I forgot to mention in my earlier post is that after zeroing the offsets (on the offsets page) you have to save them.

Tweakie.
PEACE