CNC Mini Mill #11: A little more work on the air spring

It seems like every time I conclude with saying the mill is now operational, I realize there’s something else I want to improve. After making the new air spring bracket, I finally wanted to fix the air spring scraping against the inside of the column. This would require making a new bottom mount for it, …

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CNC Mini Mill #10: A better air spring bracket, and some tweaks

As I mentioned in the last post, one of the things I wanted to make was an improved bracket for the air spring that takes some of the weight of the spindle. The stock bracket is a ~300mm long, 10mm diameter steel rod, mounted with two M6 screws on the side of the spindle, threaded …

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CNC Mini Mill #9: Spindle and coolant control

With the limit switches working, it was time to tackle the spindle control. The spindle is normally controlled with on/off switches and a speed knob on the spindle itself, but for CNC use it’s useful to have the ability to run the spindle from the G-code. I ordered a “CNC spindle control kit” with the …

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CNC Mini Mill #7: Another kind of shield

After talking about the ill-fated Arduino shields, here’s something more pedestrian. Whenever I’ve used the mill, I get chips everywhere and they get dragged into the house. It also feels a bit sketchy using the Superfly cutter without any kind of protection, since if the insert holder were to come loose it would go flying …

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CNC Mini Mill #6: The Arduino shield

In the post that talked about how I burned out the Arduino, I concluded with the need for a dedicated 48V-to-12V converter that would supply power to the Arduino but also to the coolant solenoid and various other things that might need 12V. Unfortunately a switching buck converter is a bit more complicated than just …

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CNC Mini Mill #5: Correcting the X-axis

In the previous post I talked about how the mount for the X-axis stepper motor in the CNCFusion kit didn’t line up the motor with the ballscrew axis. I realized that the clearest way of showing this was to bolt the motor mount directly to the thrust bearing mount. Any misalignment should then be obvious. …

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CNC Mini Mill #4: Small tweaks

In the previous posts I described the electronics box and motion controller. (Newsflash: The Arduino Due survived! There was only a shorted input capacitor. When I removed that, it worked again, and I so far haven’t found anything that’s really broken. Amazing, dodged another bullet there.) This post will focus on the physical mill setup. …

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The mini mill electronics box

The last post explained what the motion controller needs to do. This post will deal with the actual assembly of the electronics. The G251X motor controllers can run up to 50V, and higher voltage makes higher speeds possible (you need the higher voltage to counter the back emf from the motors, which gets higher the …

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The mini mill motion controller

The last post described the physical setup of the mini mill CNC conversion. Apart from adding motors to the mill, you also need something to control those motors. Most people seem to just get a G540 motor controller from Geckodrive and hook it up to the Mach3 CNC software. This seems to be a nice “turnkey” solution …

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