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Offline Ray

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Help with Tool Offset
« on: August 06, 2009, 01:24:44 PM »
Hello again.  I want to use a 1/8 inch endmill and have it cut outside the lines in the drawing/tap file.  How do I do that in Mach3 and in tap file?  Thank you.  Ray

Offline Ray

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Re: Help with Tool Offset
« Reply #1 on: August 06, 2009, 07:54:47 PM »
Better wording of original post.  This may not be an Offset.  I want Mach3 (Milling) to cut outside of the lines instead of on the line.  I don't know how to do this.  Using 1/8 inch dia. endmill.  Would appreciate assistance.  G-code file or DXF can be provided if needed.  Thanks, Ray
Re: Help with Tool Offset
« Reply #2 on: August 06, 2009, 08:12:39 PM »
You will need to add a G41 or G42 code to your GCode in order to cut outside your line.

The G41 or G42 code depend if your are climb milling or conventional milling or to the right or left of your line.

« Last Edit: August 06, 2009, 08:24:08 PM by ostie01 »

Offline Ray

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Re: Help with Tool Offset
« Reply #3 on: August 06, 2009, 08:56:10 PM »
Thanks ostie01 for the reply.  Do you mean I just put G41 in my program and that is all?  Like put it in before the G0?  Do I have to put any XY numbers in other than my existing code to let it know anything?  Does putting only G41 tell Mach3 to cut outside the lines?  Ray
Re: Help with Tool Offset
« Reply #4 on: August 06, 2009, 10:06:13 PM »
If you machine without the G41 or G42 in your code, the program will take into account the center of the tool, regardless what is the diameter of your tool.

With the G41 or 42 code, the program will take the tool diameter into account.

So what you can do, put code in your program to get close where you start to machine.

Place the G41(climb milling) or G42(conventional milling) into your code.

Put the minus Z value you want

Machine your part.

Lift the Z

Put the G40(remove the offset diameter or the tool)

And that's it.

But mach3 must know what tool number you're using, and it's diameter

Just look at second picture, this is an example where to place the G41 or G42 code.

And take a look at this website, click on G41 or G42(white letter) This will explain better than me

http://www.cncezpro.com/gcodes.cfm

Hope this help, Jeff

Offline ger21

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Re: Help with Tool Offset
« Reply #5 on: August 06, 2009, 10:23:40 PM »
You'll need a leadin move where the comp is applied. You can add the G41/G42 one of three ways.

G42 D1 where D specifies the tool # and uses that tools radius
G42 P0.0625 where P specifies the tool radius
G42 (by itself) which uses the current tools radius

And G41 is not necessarily climb cutting. It's offset left. G41 is climb cutting an outside profile, but conventional cutting an inside profile. G42 is offset right, and opposite of G41.

There are quite a few threads here on cutter compensation with examples and better explanations.
Gerry

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Offline Chip

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Re: Help with Tool Offset
« Reply #6 on: August 07, 2009, 03:12:27 AM »
Hi, Ray

You could also offset your line's in your Cad, 1/2 cutter width wider and delete the original line's.

Which ever is easier for you, Cad or G code.

Chip

Offline Ray

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Re: Help with Tool Offset
« Reply #7 on: August 07, 2009, 04:28:37 PM »
Tthe hanks all you guys that assisted me with this problem.  I looked at the other 6 pages concerning this matter as suggested and the stated websites like the LinuxCNC handbook and it helped a lot.  You are all great and I appreciate you.  Thanks again.   Ray