3D printing is a subsection of additive manufacturing. Meaning, we build up our part from nothing rather than removing material from a larger block. There are many types of 3D printing such as:
SLA
SLS
FDM
& more...

^ Example of traditional milling - representing Subtractive Manufacturing

But the most common form of this, both at home & professionally, is FDM printing. FDM printers have the advantage of being the cheapest and most compact form of 3D printing. FDM printers use a very hot nozzle (210+ degrees C or 410+ Fahrenheit) to melt plastic and squeeze it down in layers, building our part from the bottom up.

Standing for Fused Deposition Modeling, FDM printers have made great leaps & bounds over the last several years. We'll be covering some of the coolest advancements in future blog posts (subscribe to our newsletter for updates on the stuff we sell & new informational blogs.

Anatomy of a Part

It's important to understand just how 3D printed parts are actually constructed. We don't print solid parts, as they would be very expensive & time consuming. Instead, we print solid walls and a partly hollow inner structure. This is shown in the pictures below.

^ You can also see the 'layers' created by building the part up from bottom to top.

Infill

The main things to consider with part infill is percentage & pattern. Generally, parts are printed ~10-15 percent but for strength we may want to print higher. There are no concrete values for this but max strength is generally around 75%. Printing any higher is usually going to waste material and time with no increase in strength.

As far as patterns go, grid is default in many slicers and it's not very good. For simplicity's sake, I generally recommend Gyroid for most use cases.

Layers

Layer Height

Layers are most commonly changed via the 'layer height'. This is going to range anywhere from 0.08 to .28 mm depending on several different factors. When we change this value, we're simply telling the printer how much it should move the part down (or printhead up) every layer.

'Standard' layer heights are generally 0.16 or 0.2 mm. These values balance speed, detail, and strength very well. Using smaller layers are going to make your parts look nicer but take substantially longer. Going too small and the printer nozzle won't be able to place that little plastic accurately, go too large on the layer height and we can't melt enough plastic to keep up. 

Perimeter Count

Another thing we might like to change is the number of perimeters every layer. This is the best way to increase strength and is usually more important than our infill percentage (within normal bounds of course). For prototyping, we'll use 2-3 just to get the print done. However, these parts are going to be quite weak for functional parts. We recommend 6-8 outer perimeters if you're printing for strength.

^ Left, I would describe as a prototyping part (15% infill w/ 2 perimeters). Right, I would call a very strong functional print (50% infill w/ 8 perimiters)

Conclusion

That's all we'll be covering today, but we'll write other posts on various aspects of 3D printing, laser cutting, CAD modeling, and more. Again, please subscribe to our email list if interested in any of those topics or to be notified of new product releases to our store.