Fastening and Attaching Delrin

Heat Staking
Heat staking is when a peg from one piece fits into a hole from another piece the protruding peg is melted and fuses on to the other piece. This creates a pretty strong hold between the two pieces. The method generally limits the type of joint you create unless you get creative. It seems sturdiest with a square peg and hole at a right angle, though you could try a rod and melt enough so that that it doesn't fall into the hole.

Piano Wire

Two pieces of Delrin can be attached by drilling a hole through them and stringing through piano wire. We have the option of thicker or thinner wire and if we want a pressed fit or a running fit. The running fit has some wiggle room and you can rotate the pieces around it. The pressed fit connects the two pieces and there is no movement between them or the wire. This works for keeping two pieces together along a vertical line.


Notches and Pegs
For notches and pegs, I designed on Solidworks my own notches and pegs. The thickness of the Delrin was 49.6 mm so the center notch on the board was that thickness. The notches  above and below that notch were .1 mm larger or smaller than the ones next to it. The pegs were made with exact dimensions of the center notches. When I put the peg into the notches, I found that the pegs fit into the the center notch quite tightly. It fit into the wider notches with some wiggle room but not at all into the smallest holes. The notch .1 mm smaller fit very tightly and would not budge. Again we are limited to 90 degree joints.

Bushings
Essentially a tube that fits over a rod. Bushings can be difficult to make since the inner diameter must be the perfect diameter for whatever purpose you need them for (tight fit or loose fit). Bushings can be used as spacers between two pieces or they can be used to prevent  the rod from sliding around in wholes.
Loose Fit: The rod is able to rotate in the bushings
Tight Fit: The bushing rotates with the rod