Proxxon CNC Conversion Makes A Small Mill A Bit Bigger

The Proxxon MF70 mini-mill is a cheap and cheerful, but decently made little desktop mill. As such, it’s been the target of innumerable CNC-ification projects, including an official kit from the manufacturer. But that didn’t stop [Dheera Venkatraman] from sharing his Big Yellow take on this venerable pursuit with us!

This isn’t simply a CNC modification, it’s a wholly 3D-printed CNC modification, which means that you don’t already need a mill to make the usual aluminum pieces to upgrade your mill. And perhaps the standout feature: [Dheera]’s mod basically doubles the Y-axis travel and adds an extra 15 mm of headroom to the Z. If you wanted to stop here, you would have a bigger small manual mill, but as long as you’re at it, you should probably bolt on the steppers and go CNC. It’s your call, because both models are included.

[Dheera] also built a nice enclosure for the MF70, which makes sense because it’s small enough that it could fit on your desktop, and you don’t want it flinging brass chips all over your bench. But as long as it’s on your desk, why not consider a soundproof enclosure for the MF70? Or take the next step, make a nice wooden box, mount a monitor in it, and take the MF70 entirely portable, like this gonzo hack from way back in 2012.

Soundproofing A CNC Mill Conversion

The Proxxon MF70 is a nice desktop sized milling machine with a lot of useful add-on accessories available for it, making it very desirable for a hacker to have one in his or her home workshop. But its 20000 rpm spindle can cause quite the racket and invite red-faced neighbors. Also, how do you use a milling machine in your home-workshop without covering the whole area in metal chips and sawdust? To solve these issues, [Tim Lebacq] is working on Soundproofing his CNC mill conversion.

To meet his soundproof goal, he obviously had to first convert the manual MF70 to a CNC version. This is fairly straightforward and has been done on this, and similar machines, in many different ways over the years. [Tim] stuck with using the tried-and-tested controller solution consisting of a Raspberry Pi, an Arduino Uno and a grbl shield sandwich, with stepper motor drivers for the three NEMA17 motors. The electronics are housed inside the reclaimed metal box of an old power supply. Since the Proxxon MF70 is already designed to accept a CNC conversion package, mounting the motors and limit switches is pretty straightforward making it easy for [Tim] to make the upgrade.

Soundproofing the box is where he faced unknown territory. The box itself is made from wooden frames lined with particle board. A pair of drawer slides with bolt-action locks is used for the front door which opens vertically up. He’s also thrown in some RGB strips controlled via the Raspberry-Pi for ambient lighting and status indications. But making it soundproof had him experimenting with various materials and techniques. Eventually, he settled on a lining of foam sheets topped up with a layer of — “bubble wrap” ! It seems the uneven surface of the bubble wrap is quite effective in reducing sound – at least to his ears. Time, and neighbours, will tell.

Maybe high density “acoustic foam” sheets would be more effective (the ones similar to “egg crate” style foam sheets, only more dense)? Cleaning the inside of the box could be a big challenge when using such acoustic foam, though. What would be your choice of material for building such a sound proof box? Let us know in the comments below. Going back many years, we’ve posted about this “Portable CNC Mill” and a “Mill to CNC Conversion” for the Proxxon MF70. Seems like a popular machine among hackers.