02:19 am
21 June 2021

How to: Create joints with the 3D pen

How to: Create joints with the 3D pen

Drawing to Doodling

I like to draw.  A lot.  Growing up, I would fill sketchbooks with all sorts of characters.  Oftentimes my favorite cartoon or comic book characters were the focus of my drawings, oftentimes it was characters that I designed myself.

Doodling Figures

The very first thing I tried to Doodle was a figure: two arms, two legs, one body, one head, but all one solid piece.  It was a little messy, but as I kept Doodling different figures, and as I refined my process I grew happier with the finished result.

Creating Movement

Then I realized that I would be able to connect separate pieces, AND that they could move independently as long as i didn’t melt them together.  The 3D pen joint was born.

The first iteration of my 3D pen joints were for a small action figure that had arms and legs that that flopped loosely; it was basic, but it at least proved the theory and got the ball rolling!  Since then I have developed  methods for creating joints, the movement of which is as effective as that of your typical store-bought action figure.


Step by Step

To make joints with the 3D pen, I typically start with ABS plastic.  PLA works as well, but i find ABS gives you a little more flexibility when working with this particular method.  In addition to the 3D pen, I use a piece of 3mm wire (you’ll see why soon) – any piece of metal that is the same width as a 3D pen strand of plastic will do, as long as you can remove the wire after you Doodle around it. 


Step 1:

Doodle a small rectangle of 1cm x 1/2cm plastic on the paper (my plain old sketchbook is my preferred surface).


Step 2:

Then lay down the piece of wire across the rectangle.  Hold it in place and begin to Doodle plastic in thick tight mounds on either side of it. 


Step 3:

Build the plastic up on both sides (this is important for the strength and smoothness of the joint).  When you’ve got both sides to be around the same height as the wire proceed to connect them across the top.


Step 4:

From there I simply pull out the piece of wire and push in a strand of plastic that hasn’t gone through the 3D pen yet.  Note that sometimes the stress of the new filament going through the loops will crack the looped plastic.  This is okay and can be used to your advantage, simply add some plastic over the crack to make the joint tighter or looser. 


Step 5:

I then cut the inserted strand to my preferred length and “cap” the ends with plastic so that it can’t be pulled loose.


Step 6 and beyond:

From here you can add on whatever you like, an arm, a leg, a wheel, anything that you want to pivot smoothly in place.

Here are some examples of items I have made with this very same technique:

Doodle-Diver Doodle-joint-hand Doodle-joint-human

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