Daedelus
29-03-2013, 06:39 PM
How flat is your blank piece of copper for isolation milling a PCB?
There could be a big difference between the lowest and highest point on your board leading deep cuts in some areas and other areas where the tip of the tool is barely touching the surface. This could be caused by an un-level table or flex in the copper blank.
One solution is to autolevel the board before milling, i.e. probe an area for height and adjust the Z axis during the milling process, and I am working on easy to use software to do just that.
In the meantime I have made some software to tell you how level your board actually is.
It does this by first generating some GCode which can be run on your CNC control software (I have only tested on linuxCNC).
The GCode probes an area and logs the coordinates of each probe.
This log file can then be fed back into the software and the highest / lowest points etc can be obtained.
One thing to note is that in linuxCNC the log file gets saved in same directory as your .ini file by default so look for levelprobe.log there. You also need a working probe and the Z height needs to be zeroed to within 10mm of the board.
Here is a screenshot of said software after loading the log file:
8571
This tells me that there is more than 0.2mm difference between the highest and lowest probed points.
Download here: 8572
To run the jar file you should be able to just double click it. If not, try typing "java -jar [filename]" from the command line
The steps to use are:
1. Fill in the fields on the left with desired values for probing the area and click on "Generate GCode File". Save the file.
2. Load and run the GCode file in linuxCNC (Not sure if it works in Mach3 or anything else). Allow the file to finish probing (This generates a log file with the logged coordinates).
3. In the software click "Load Log" and select the newly generated log file. This will display useful information about the probed area.
Have a go and I will try to post a video of the probing software tomorrow.
I have probably forgotten something so any questions, advice or feedback, let me know.
There could be a big difference between the lowest and highest point on your board leading deep cuts in some areas and other areas where the tip of the tool is barely touching the surface. This could be caused by an un-level table or flex in the copper blank.
One solution is to autolevel the board before milling, i.e. probe an area for height and adjust the Z axis during the milling process, and I am working on easy to use software to do just that.
In the meantime I have made some software to tell you how level your board actually is.
It does this by first generating some GCode which can be run on your CNC control software (I have only tested on linuxCNC).
The GCode probes an area and logs the coordinates of each probe.
This log file can then be fed back into the software and the highest / lowest points etc can be obtained.
One thing to note is that in linuxCNC the log file gets saved in same directory as your .ini file by default so look for levelprobe.log there. You also need a working probe and the Z height needs to be zeroed to within 10mm of the board.
Here is a screenshot of said software after loading the log file:
8571
This tells me that there is more than 0.2mm difference between the highest and lowest probed points.
Download here: 8572
To run the jar file you should be able to just double click it. If not, try typing "java -jar [filename]" from the command line
The steps to use are:
1. Fill in the fields on the left with desired values for probing the area and click on "Generate GCode File". Save the file.
2. Load and run the GCode file in linuxCNC (Not sure if it works in Mach3 or anything else). Allow the file to finish probing (This generates a log file with the logged coordinates).
3. In the software click "Load Log" and select the newly generated log file. This will display useful information about the probed area.
Have a go and I will try to post a video of the probing software tomorrow.
I have probably forgotten something so any questions, advice or feedback, let me know.