Tool Offsets and Dolphin
Posted by
machines@n...
on 2001-10-01 05:21:17 UTC
I have put two screen shots of the way Dolphin handles tool offsets
on my web site at
http://homepage.ntlworld.com/machines/offset1.jpg
http://homepage.ntlworld.com/machines/offset2.jpg
This text file is also there at
http://homepage.ntlworld.com/machines/offset.txt
The screen shots just show on a very simple file how easy it is to
use tool offsets or if you prefer, not to use them.
Some programs at present like CNC Pro from Yeager can't handle
G41/G42 tool offsets so you have to draw the offset path and process
that.
Dolphin allows you to chose from a menu how you want to do this.
The screen shots both show the same part, in this case a simple 2"
square is to be machined with an 0.5" diameter tool. I have chosen
these sizes as they generate easily understood numbers.
If you look at offset1.jpg you will see the black square with the 0,0
zero point at bottom left. The blue square is the tool path. This has
been generated by the program adding the tool radius to the square.
If you look at the code you will see in lines 160, 180, 200, and 220
that the allowance has been made. This is fine is all you want is a
shape with no firm tolerance or your controller can't handle tool
offsets.
If however you need to control the part size using tool offsets then
take a look at offset2.jpg
By just selecting "Use part surface" in the options check box you can
see that the black square and the blue tool path are one and the
same. In lines 150 to 180 you have the exact 2" square defined but at
the start of line 140 the tool offset is called up.
In both cases just the simple 2" square had to be drawn or imported
as a dxf file. The approach and depart points are automatically
generated from the Approach/Runoff option.
The same post processor file is used the only thing that has changed
is the check box on the part surface command. Any of these commands
can be called up again and edited, there is no need to touch the
original drawing. If you decide to use a 3/8" tool then edit the tool
and repost the file and the code will take the new tool into account.
Thank you for you time.
John Stevenson
on my web site at
http://homepage.ntlworld.com/machines/offset1.jpg
http://homepage.ntlworld.com/machines/offset2.jpg
This text file is also there at
http://homepage.ntlworld.com/machines/offset.txt
The screen shots just show on a very simple file how easy it is to
use tool offsets or if you prefer, not to use them.
Some programs at present like CNC Pro from Yeager can't handle
G41/G42 tool offsets so you have to draw the offset path and process
that.
Dolphin allows you to chose from a menu how you want to do this.
The screen shots both show the same part, in this case a simple 2"
square is to be machined with an 0.5" diameter tool. I have chosen
these sizes as they generate easily understood numbers.
If you look at offset1.jpg you will see the black square with the 0,0
zero point at bottom left. The blue square is the tool path. This has
been generated by the program adding the tool radius to the square.
If you look at the code you will see in lines 160, 180, 200, and 220
that the allowance has been made. This is fine is all you want is a
shape with no firm tolerance or your controller can't handle tool
offsets.
If however you need to control the part size using tool offsets then
take a look at offset2.jpg
By just selecting "Use part surface" in the options check box you can
see that the black square and the blue tool path are one and the
same. In lines 150 to 180 you have the exact 2" square defined but at
the start of line 140 the tool offset is called up.
In both cases just the simple 2" square had to be drawn or imported
as a dxf file. The approach and depart points are automatically
generated from the Approach/Runoff option.
The same post processor file is used the only thing that has changed
is the check box on the part surface command. Any of these commands
can be called up again and edited, there is no need to touch the
original drawing. If you decide to use a 3/8" tool then edit the tool
and repost the file and the code will take the new tool into account.
Thank you for you time.
John Stevenson