[harry4516]

I tried to cut a thread using two roughing and two finishing passes.
This is the result:

first roughing pass:
N80 G32 X4.35 Z-10.0

second roughing pass:
N100 G01 X4.08 Z0.085 F1.5

first finishing pass:
N125 G01 X4.08 Z0.085 F1.5

second finishing pass:
N150 G01 X4.08 Z0.085 F1.5

The second roughing pass already cuts the full depth.
Both finishing passes are doing nothing, just moving at the same X.

The attachment contains the Dolphin CNC file and the G-code file (latest Mach3 PP).

The simulation already shows that the finishing passes are just cutting the old path.

Any solution, or what am I doing wrong ?

Harry

[andre-dolphin]

Hello,

I'll take a look and see where the problem lies.

ATB
Andre

[harry4516]

thank you, Andre

[andre-dolphin]

Hello Harry,

Sorry for the delay, here is the explanation of what it's doing.

One thing to bear in mind is that the finish pass was previously called a "spring" or "chasing" cut.

If you have a thread depth of 5mm on a 20mm bar with 3 roughing cuts, you will get the depths 20, 17.5 & 15 - this will cut the required thread, if you add a finish cut you will get a further cut at 15 to "finish" the depth, this will take out any "spring" in the tool or workpiece.

Adding further finish cuts will only result in more passes at the final depth, this could be required for very tough materials.

Hope this clear.

ATB
Andre