3d printing is exploding these days as prices continue to come down in price. We’re starting to see many 3d printers come down to below the $2000 mark. This means in future we will be able to print a ton of stuff – just as exciting as when CD burners first came out.

A lot of people may be confused as to the differences of CNC machining and 3d printing. Although both may get the same result depending on the material and the complexity of the project, the two different types of manufacturing are in fact quite different.

Above you will see a cool video on the 3d printing process including the use of a scanner to even ‘scan’ a product beforehand. Typically both a 3d printer and a cnc machine will need a file to work off of.

What happens is that you yourself can make a 3d file or you can (now and in future) get a 3d file pre-made and import it into your 3d printing program. This program then simulates the build and sends the information to the actual 3d printing machine.

What happens typically is that a 3d printing machine will build up a product from the bottom up. This happens in layers, so as each layer moves up – the material from the machine gets set and stays in place to build a design or product up layer by layer.

Now the quality of the 3d printed object really depends on the resolution of the machine. So the thinner each layer is, the better surface quality the final product is going to have. The rougher the resolution, the rougher the surface finish will be. From my experience outsourcing 3d printing, it is ALWAYS best to get a better resolution to stop you having to finish off the product after it has printed – especially with smaller objects that need to be printed.

CNC machines

A cnc machine is a lot different to a 3d printing machine, first of all, it doesn’t print, it routs out material to create an object. So with a 3d printing machine, you start with no material and add material layer by layer to form an object, while cnc takes a piece of material and works backwards and ‘carves’ out an object.

CNC is typically used for larger objects. This is because drill parts are larger – so they just aren’t small enough to create intricate parts like fine jewelry. Now also with cnc – there are different kinds of cnc cutting or manufacturing. Waterjets, laser cutting, plasma cutting and regular routing with drill pieces each have their own pluses and minuses.

The good thing about cnc cutting or routing is that it is still highly accurate, but needs to be done on a higher scale. For example: Using a cnc machine to cut shapes of aluminum for a kit-set boat as opposed to a plastic miniature chair.

In terms of machines, we have looked at many in the past here, here and here.

So in conclusion – for smaller objects that don’t need a lot of strength –  a 3d printer is fine. But once you start needing larger objects and you want to work with tougher material like steel or aluminum, then you’re going to need a heavy duty cnc machine.

Also remember that with compound surfaces, 3d printing has a big leg up and the detail can  be amazing. Unless you have a 5 axis cnc machine, then you just can’t make complex shapes without having to take out your working block and re-positioning it for a 3 axis cnc milling machine.

What are you more excited about? CNC machines or 3d printers? Leave your comments below!