Hi all,

I'm also hoping to have a go at this - I had a play around with writing the G-Code for it earlier in an effort to better understand what's going on, I've got something that might work - I wouldn't mind a bit of a sanity check on my process, though...

For the sake of argument I'm going to be cutting an M4 thread. For the cutting tool I'm going to use an M4 tap ground down to a flat nose / single row of cutting teeth - I'll be using this tool for both the internal and external threads, but when cutting the external thread I'll adjust the radius to cut me a slightly deeper groove for a bit of clearance (...maybe I'm better off doing that on the internal thread..?)

These threads don't need to be ISO compliant, so long as they work together that'll be fine!

Here's the code I came up with for the external thread (probably ought to be a G17 in there..) along with a vid of Linux CNC running it:

%
G90 G21 G40 G49 M6 T1
G0 X0 Y0 Z5
G0 X-5
G1 Z0 F500
G1 X-3.571
G2 X0 Y-3.571 Z-3.5 I3.571 J0 P5 F500
G0 X-5
G0 Z5
G0 X0 Y0
M2
%

(The radius of the arc is 3.571 as that'll bury a 4mm tap 0.429mm (male thread height) into the 4mm stock to be threaded.



Does all of this look about right, or wishful thinking..? I guess I'll just have to give it a go..!

Wal.