3D Printing - Bendy, Detailed or Sturdy (Part 1)

With my first bee printed I had an abundance of questions and ideas.  This 2-part post and the next post happened in parallel but I’ve tried to put some order on the chaos.

I still find it difficult in 3D printing to find the line between the effect of the material used in the print and the effect of the printer.  Both advance and change so much, it’s still hard to tell.  The design changes are explained later so we will start with the materials. 

Check out the picture of the bee from the last post.  This was my first successful bee and it was done in yellow PLA, probably one of the most popular materials for 3D printing.  If you look closely you can see very thin horizontal lines in the body and jagged edges.  The lines are because the printer prints in layers of plastic.  The thickness between the lines is determined by the nozzle diameter.  Better printers mean thinner gaps.  This print had quite a fine nozzle diameter compared to some of the prints I have seen. 

As you can see, the wings stick out sharply in this design.  However, the printer can’t print on thin air.  The printer would have had to print skinny and easy to break pillars under each wing.  When the bee finished printing, these supports were manually broken off.  This leaves slightly jagged edges on the bottom edge of the wing.  These edges can be sanded down after printing to get a smooth finish if needed. 

The inside of this piece is partly hollow to save material and print time.  It also helps to make sure the part doesn’t bulge.  To keep it strong, lines of support material are printed inside it.  Usually in a honeycomb or criss-cross pattern.  It also keeps it light and cheap while maintaining its shape.

I started to get a little more adventurous at this point.  Resin is a very different material to PLA.  It starts out as a liquid and when printed it dries and hardens in UV light.  Compared with PLA, the layers of print stick together more firmly.  It can still contain soft lines from printing depending on the printer quality.  The orange bee has faint lines but the clear bee is almost completely smooth.  This clear bee has also been sanded to finish which makes it hard to determine the exact quality of the print.  These pieces are also completely solid unlike the first yellow bee. 

The final thing I will say is that the resin is on the brittle side.  The details are covered in the design post but it’s important to keep in mind.  Any weaknesses in the design will most likely snap when printed in resin if any force is applied to them.