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.

The Pi CNC Controller

pi

Back in the olden days, the latest and greatest CNC machines had minicomputers bolted onto their frames, replete with paper tape readers and seven segment displays. For the home CNC machinist of today, these hulking electronic brains are replaced with something a little more modern – desktop computers with parallel ports. Having a box filled with computers and motor drivers is just too cool though, and this tiny Raspberry Pi CNC controller fits the bill quite nicely.

The controller uses a Raspberry Pi as the brains of the device, but there aren’t too many options out there for stepper motor control in Pi land. There are, however, dozens of CNC shields or the Arduino. The Pi AlaMode board is able to provide voltage level conversion between the CNC shield and the pi, and also has the nice bonus of a battery-backed real time clock.

With some proper connectors, lighted buttons, and a beautiful cable sleeving job, this Pi CNC controller would be well suited for any of the desktop CNC  or engraving builds we see from time to time.