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Author Topic: Tool Change  (Read 8580 times)

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Offline Graham Waterworth

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Re: Tool Change
« Reply #10 on: January 03, 2008, 04:45:55 PM »
I do not see the big problem in entering 3 words 'G43 T1 M6' for each tool used, this call sets the height offset and loads the diameter offset ready for use by G41 or G42.

One of the reasons Mach works this way is so that tools can be pre-selected by calling T2, then the tool changer is ready for changing by the M6 command

Graham.
« Last Edit: January 03, 2008, 04:51:06 PM by Graham Waterworth »
Without engineers the world stops
Re: Tool Change
« Reply #11 on: January 03, 2008, 05:21:15 PM »
Graham,
Your right about the M6 command.  I don't have a tool changer on this machine, so the M6 command doesn't really apply to me.  I'm used to using a simple T1 command to change a tool.  I still don't understand why I have to use the G43 command every time I make a toolchange.  Is that how it was designed?  One thing that was throwing me off is the fact that you can make a height offset that doesn't match the tool.  For example, T1 M6 G43 H2 calls for tool 1 but uses the tool 2 height offset.  What I didn't realize was that G43 also would recognize the "T1" word and pull in both offsets and didn't have to have the "H1" word.  I'm happy with this, now.  Although, I don't understand why you would ever want to make a tool with two different offsets.  And is there a way that you can just use G43 at the beginning of the program and make it so that you don't have to have it on every tool change line?  I don't mind doing this, as long as I know that I have to.  But every other machine I've used simply uses the T# word to do all of it.  Thanks for your help!
-Leith
Re: Tool Change (BREAKING TOOLS)
« Reply #12 on: January 20, 2008, 07:41:03 PM »
I found this topic investigating some unexpected G43 behavior after "upgrading" from a previous version of Mach3

It appears that "T# M6 G43 T#" does not change the DRO offset as I expect it to.
(I expect to change the DRO to reflect the height offset value without moving the machine)

G43 SOMETIMES moves the machine Z axis. (I've broken several tools and ruined parts because of this.) 
In this "sometimes" mode repeatedly issuing G43 (tested with the MDI) repeatedly moves the machine Z axis.
Sometimes appears to be:
   if current tool <> tool specified in "T# M6 G43 H#"
       Then machine does not move (offset changed in DRO)
   if Current tool = tool specified in "T# M6 G43 H#"
       Then Machine moves Z axis by offset of H

?!?!?
 
My post always issues the tool change like this:
T# M6 (apparently does nothing except change the Tool # display)
G43 H# (Tool height offset is applied to DRO (or the Machine Z axis is moved) at this command)

I'd love to eliminate this G43 command from my post.

But why wasn't this ever a problem before in Mach2 or the previous version of Mach3 (Current 3.00)
The Z axis never moved when a tool offset was issued. See below from UsingMach3Mill
« Last Edit: January 20, 2008, 08:18:44 PM by Erichtg »
Re: Tool Change
« Reply #13 on: January 20, 2008, 08:23:41 PM »
I dont put the g43 in the tool change line on any of my machines , just T0101 m6 for the lathe , t1 m6 for the mill and dont have any problem with offsets. M6 is the std callout for tool change wether its being done manualy or with a changer, not familiar with a cnc machine that does tool changes with just the T* command and no M6 . My Milltronics machining center sees an M6 with no T callout afterwards and just stops the spindle, and raises the head  waiting on a manual tool change. If am running a file with T1 and , 1/4" mill , and then call out T2 (3/8" mill) without the M6 behind it the machine will not stop for a tool change and will continue to run the file with the 1/4" mill
Re: Tool Change
« Reply #14 on: January 20, 2008, 08:32:06 PM »
I'm going to create a new thread for my mystery moving z axis.