4th axis DIY CNC aluminum machining with handwritten gcode

Machining a little standoff out of 6mm aluminum rod on my handbuilt CNC machine with a small 4th axis module from aliexpress. No CAM used for this, wrote the gcode file by hand, machine controlled by Mach3. 12000 RPM spindle, with a 3mm two flute endmill. Video is accelerated.

[@jarisipilainen3875]

6x lenght? use live centre lol.that bend on pushing it finger

[@chrisdj85]

Could you share the gcode? How you program the 4th axis to rotate the right amount of turns? Thank you very much.

[@kostix777]

Sure! Let me get to the computer and I can share the file. I configured the rotation on A axis. In mach3 motor tunning settings you have to setup the steps per inch in the form of steps per angle. You calculate that by knowing your stepper steps per revolution, the microstepping setting of your driver and gear reduction ratio on the module. In my case stepper is 200 steps per revolution, i had the microstepping at half step (so thats 400 steps per revolution), and gear reduction is 1:4, so thats makes it 1600 steps per one revolution of the actual chuck. Now to get the steps per angle you divide the 1600steps by 360degrees = 4.44444 steps per degree. You input this into the "steps per inch" of the rotary axis motor config. You also need to enable "A axis rotation" on one of the settings screens. If you get the steps per inch right, once you configure that, you can make the axis rotate by degrees, so if, say the A is at 0 and you want it to make a full revolution, you would write "A360" and it should rotate exactly 1 revolution. There are more in depth tutorials of how to setup all this in mach3, at youtube if you wish more details hehe.

[@kostix777]

Here goes the gcode: pastebin.com/wyXJr2mg

[@chrisdj85]

@@kostix777 thank you very much, I'll look at it as soon as possible.