Generating Gcode for a maxnc mini mill

[Bosco]

Does anyone here use a Maxnc mill? I purchased one from craigslist from an owner who knew as much as I do about CNC, nothing. I have been able to get it working using the preloaded files, however I created a simple project from scratch and I cannot figure out how to make the correct Gcode for the machine to read it. I am wondering if I am using the wrong post process on export?

All of the sample files that came with the mill have the file extension of ".T" I cannot figure out how to export as .T only .CN. thanks in advance.



OS: Mac OS X
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.16.6706 (Git)
Build type: Release
Branch: tag: 0.16.6706
Hash: f86a4e411ff7848dea98d7242f43b7774bee8fa0
Python version: 2.7.11
Qt version: 4.8.7
Coin version: 3.1.3
OCC version: 6.8.0.oce-0.17

[chrisb]

Can you post a small file that works with your mill? If you cannot include it in the code tags of the edit text you might zip it before attaching here.

[Bosco]

Thanks Chris, let me see what i can do.

[Bosco]

Hopefully there is a file titled "wheel.t.zip"

[bejant]

Hopefully there is a file titled "wheel.t.zip"

Yes, and after unzipping it is human readable in gedit (my Linux text editor) so that's a good start. Try opening it in your text editor and compare it with the contents of a .CN file...

[chrisb]

Hopefully there is a file titled "wheel.t.zip"

It is standard GCode, as far as I can see. There are some commands I cannot identify (I'm not at home currently) but you should be able to look them up.
I ente the file here, so others may comment directly. I inserted the (common but not necessarily needed) blanks before the command letters and some blank lines:

Code: Select all

N10 (PROG NAME WHEEL.T)
N20 (1/16 DIAMETER END MILL)
N30 (SET X AND Y AT C/L)
N40 (SET Z0 AT TOP AF MAT.)
N50 (NO OFFSETS)

N60 G90 G80 G49 G20

N70 G00 X0.1293 Y0.2226
N80 S3000 M3
N90 G00 Z.1
N100 G41 D6
N110 G01 Z-.130F20.0
N120 G01 X0.0577 Y0.1000
N130 G01 X0.3562 Y0.1005
N140 G03 X-0.0915 Y0.3585I-0.3562J-0.1000
N150 G01 X0.0577 Y0.1000
N160 G00 Z.2
N170 G40 X-0.2574 Y0.0007
N180 G00 Z.1
N190 G41 D6
N200 G01 Z-.130
N210 G01 X-0.1155 Y0.0000
N220 G01 X-0.2647 Y0.2585
N230 G03 X-0.2647 Y-0.2585I0.2647J-0.2585
N240 G01 X-0.1155 Y0.0000
N250 G00 Z.2
N260 G40 X0.1281 Y-0.2233
N270 G00 Z.1
N280 G41D6
N290 G01 Z-.130
N300 G01 X0.0577 Y-0.1000
N310 G01 X-0.0915 Y-0.3585
N320 G03 X0.3562 Y-0.1000I0.0915J0.3585
N330 G01 X0.0577 Y-0.1000
N340 G00 Z.2
N350 G40 X0.5600 Y0.6265
N360 G00 Z.1
N370 G41 D6
N380 G01 Z-.130
N390 G01 X0.5600 Y0.0000
N400 G02 X-0.5600 Y0.0000I-0.5600J0.0000
N410 G02 X0.5600 Y0.0000I0.5600J0.0000
N420 G01 X0.5600 Y-0.5680
N430 G00 Z.1
N440 G00 Z0.05
N450 G40 X0. Y0.
N460 G01 Z-0.130
N470 G01 X0.0235 Y0.
N480 G02 X-0.0235 Y0.I-0.0235J0.
N490 G02 X0.0235 Y0.I0.0235J0.
N500 G00 X0. Y0.
N510 G00 Z1.0
N520 M30
N530 G4 P1000
N540 M99

Up to the first blank lines it's only comments, then there is an initialization line and the follow the standard GCode commands:
G0 rapid move, G1 slow move straight, G2, G3 circles, X,Y,Z positions, ... FreeCAD will generate exactly these. Something special seems the G41 D6. I guess it means to mill at one side with a diameter of 6, i.e. mill 3mm besides the object border. FreeCAD can do these calculations for you.
You can have a look at the philips post processor. You don't really have to program but only set some variables. The widely used linuxcnc postprocessor is similar to configure, I don't know it as good as the former one.