Comparison of designing for a CNC laser cutter, table router and 3D printer

I’ve had my 3D Systems 2nd Generation Cube for 5 months now and after hundreds of hours testing, designing for and printing… the machine and my mind have finally clicked.

This weekend I designed two projects and both came-out 100% perfect as I envisioned them. They will be on CNCKing.com in a week or two (render depending).

I had a similar experience when I got my ShopBot Desktop… I did lots of designs with it to learn how to use it but now that I have the hang of it, designing for it is as intuitive as it is for the laser.

View this video if you aren’t familiar with CNC machine options.

https://vimeo.com/204703236

Challenge with a CNC laser

By far the biggest hurdle to get over when designing for a laser cutter is interlocking parts and material options on a 2D surface. Unlike a router or 3D printer, you primarily have access to only a 2D axis (X, Y) and although you can do engraving to create depth, it’s tricky to get right.

It’s really more of a cut all the way through and engraving machine. Your design might call for bevels… an out-of-focus laser could technically do that but it’s a hassle.

Your design might call for parts as thin as 1mm which you could technically do with a laser but it’s a hassle depending on material and thickness (good luck doing it with 6mm plywood for instance).

Up until this point, there really was no easy way to learn all the intricacies involved with designing for a CNC laser cutter.

Challenge with a CNC router

As for a table router, you have the precision of a laser cut with a round bit – instead of cutting 0.2mm away with a laser, your bit diameter is the deciding factor. You also have to content with forces put onto your material pushing and pulling it. Where you lose on material use optimization, you gain on the Z-axis… the same precision you had on X, Y!

The reason is simple, the laser doesn’t know depth, so you have to manually test while for a CNC table router, it knows exactly where it is at all times on all 3 axis. Want a bevel? No problem! Want to have sharp outside corners… no problem… inside corners? Well, you can’t cut a square hole with a round bit.

That’s a limitation, you could get around it using dog bones and other methods like using a very small bit but it isn’t worth the hassle. You could technically cut a 1mm thin wedge but like a laser, it isn’t worth the hassle.

Up until this point, there really was no easy way to learn all the intricacies involved with designing for a CNC table router.

https://vimeo.com/204711894

Challenge with a 3D printer

The biggest challenge with 3D printing – by far – is the 3D modeling part. With a laser cutter or table router, you are PRIMARILY designing in a 2D environment (X, Y) and Z is used for cutting all the way through (pockets for table routers excluded). Although you see a lot of 3D printed objects that really 2D which are extruded… that doesn’t even come close to describing or taking advantage of the true abilities a CNC 3D printer has.

You have all the precision benefits you get in CNC lasers and routers plus the additional option to actually build on the Z-axis. Because the method is additive and not subtractive, essentially, ANYTHING is possible though how limitless your options really are depends more on the machine (and budget) than the promise of the technology itself.

Up until this point, there really was no easy way to learn all the intricacies involved with designing for a CNC 3D printer.

https://vimeo.com/204718076

Overview of CNC designing

As you can see, your design decisions are dictated by the CNC  you are designing for and to a lesser extent, the actual model of your machine (a 3D plaster printer has different properties than a 3D Systems Cube)… the options available with a ShopBot Desktop are different than one of their PRSalphas ( 144″ x 60″ x 6″ or 3.66m x 1.52m x .15m surface!) and a Trotec Rayjet vs a Trotec Speedy 1500.

You have bed sizes, speeds and stepper motor differences that you want to account for in your design. I haven’t even touched on the benefits of CNC plasma cutting… something I’m anxious to get into as well!

Like anything in life, you have to give yourself the freedom and flexibility to screw-up, learn and apply the lessons you’ve picked-up with each project. These CNC machines can be as fun or migraine inducing as you want… they can be expensive or cheap as you want… and they can be as much a profit center as a hole in your wallet. The difference is based on perception and knowledge.

This is why I’ve been writing books for all these years and why I’m very happy to have my upcoming book out in about a month. It will teach you so much of what I wished I knew, saving you time and money.

I couldn’t find the resource that I wanted so I built my own and I look forward to sharing it with the world shortly!

CNCKing.com V4 book cover – out in September 2013!