Re: [Pcb2gcode-devel] isolation cutter/engraver vs milling cutter for outline

[Alan C. <acondit@IPNS.COM>]

Patrick,

I have submitted this board to BatchPCB.com to check it with their DRCBot and it passed with no problems. The gerbers are not from gEDA but rather from Osmond-Cocoa for the Mac. I have a bunch of existing designs from before I got gEDA compiled.

The problem with failing to "fulfill all clearance requirements" seems to be related to when I set the board up with "copper flood" on the front and/or back.

The .png files look like I would expect the pcb to look. However, the front.ngc and back.ngc files don't have any gcode for any traces.

----
( pcb2gcode 1.0.6 )

G94     ( Inches per minute feed rate. )
G20     ( Units == INCHES.             )
G90     ( Absolute coordinates.        )
S30000  ( RPM spindle speed.           )
M3      ( Spindle on clockwise.        )

G64 P0.002 ( set maximum deviation from commanded toolpath )


G00 Z1.00000 ( retract )

M9 ( Coolant off. )
M2 ( Program end. )

----

I had these values set, for a 1/32" milling cutter and a 0.007" engraver. 

cutter-diameter=0.03125
offset=0.0035

Alan
---

Alan Condit
1085 Tierra Ct.
Woodburn, OR 97071

Email -- ac...@ip...
Home-Office (503) 982-0906

> Hi Alan,
> 
> this is what the --offset= parameter is used for.
> You can set it to the radius of your isolation cutter to mill everything 
> exactly as specified in your gerber file, but you will frequently want 
> to set it to a higher value (double or more).
> If there are contentions due to a high offset (e.g. between IC pins), 
> the program warns you and temporarily reduces the milling offset.
> 
> I suggest you take a small testing gerber file and try different values 
> for --offset so you see how it works.
> 
> -- Patrick
> 
>> I have set up a millproject file for my parameters. How do you specify the diameter of your isolation cutter, if it is different from the end mill that you use for cutting the board outline?
>> 
>> Alan
>> ---
>> 
>> Alan Condit
>> 1085 Tierra Ct.
>> Woodburn, OR 97071
>> 
>> Email -- 
>> ac...@ip...
>> 
>> Home-Office (503) 982-0906