Summer Project: The Mostly Printed CNC Machine Part 1

You know how when you see something over and over again, it finally makes an impression? Well, my current summer project has been one of those things. A number of people have built (or at least started to build), the mostly printed CNC over the past couple of months and I decided to tackle it myself. It’s been a while since I last built a 3D printer and this CNC machine uses many familiar concepts and similar hardware to what I used before.

What’s a CNC?

Computer Numeric Control (CNC) is the use of a computer to control a machine, in this case a handheld router (think Dremel) to move it around a build area. The computer is an arduino-based RAMPS system. This is the same basic concept that made 3D printing possible and has been around for a long time.

The machine I’m building will be used to mill wood and possibly metal with a drill bit attached to the toolhead of the CNC. I haven’t finalized my plan yet for what I’ll attach to the toolhead, but I’ll likely start with the handheld router (a knock-off Dremel from Canadian Tire) see how that works. The project also has the files to mount laser engravers, a 3d printer extruder and other devices. I like the idea of the laser etcher addon. It’s really easy to swap out the tools. In this video, Ryan starts with a laser and switches out to the router – it’s a good overview of what the machine is capable of:

What I really like about the MPCNC project is that it’s open source, completely customizable, uses readily available parts (with metric and imperial equivalents) that can be sourced from North American hardware stores, is very well documented, has a large community of users and is just really well designed. It’s been around for over a year now so it’s starting to mature and there was a recent update to some key parts to make it easier to build with a better design. It’s also very inexpensive. It’s roughly about $400 worth of parts if you had to buy everything at full retail. You can shave a lot off of that by buying online and I’ve discovered that I’ve got a lot of the required parts left over from previous 3D printer builds so I’ll likely spend sub $200 on mine which is crazy when you consider what a commercial CNC machine goes for ($1000s).

There is a LOT of printing required to make all the parts that will ultimately hold everything else together. Somewhere between 90-120 hours of printing. One thing I noticed right away is how well designed the parts are. I’ve printed a lot of parts for 3d printers before and none were as well designed as what Ryan has accomplished for the MPCNC. The parts can be printed on nearly any machine, print extremely well and to me, seem like will really make this project amazing.

I’m still blown away at the parts when they come off my printer (in this case I’m printing everything on a Tinkerine DittoPro). I’m using Hatchbox Green PLA (which is now available from Amazon Prime in Canada!) and the finish on the parts almost feels injection moulded.

One corner with bonus cat hair

I’ve just gotten started and am only about half way through printing all the parts necessary. I’m still debating on the size I should build it. I like the idea of a build area of 24″ x 24″ which seems like a versatile size but it makes for a full-size machine that is quite large. I used the parts calculator to determine the rail lengths. I may still cut it down to a 21″ x 21″ table to make it a little smaller but I’ll wait to decide when I’m finished printing everything.

Fellow 3D604 member, Edward, has finished his build and was the reason why I decided to attempt this. I’ve seen others build the frame and print most of the parts but Edward’s actually runs and it’s very impressive. He documented his build and I’m looking forward to seeing his machine in person soon.

I’ll be posting additional progress updates as the project continues.