Printing SK8CAD Molds Part 3: Assembly and Pressing
Now that all of your mold sections have printed out, you can assemble them into a male and female skateboard mold.
-- For the video of this process, scroll to the bottom of this post. --
Cutting backing boards with alignment holes using a CNC router.
My preferred method is using a plywood backing board I cut on a CNC router with holes that correlate to the bore holes I design into the SK8CAD mold sections. I also add in some sort of mold alignment feature in the backing boards - for example, some tabs with holes so I can install long bolts to ensure the molds are aligned. You could do something similar with a laser cutter or even 2D-printed templates that you glue onto a sheet of plywood then drill and cut manually (Inkscape is free vector design software that you can use to create a digital design; there are many other tools that can be used as well, like Fusion 360, Onshape, Illustrator, etc.)
I install heat-set inserts (like these) into the molds using a soldering iron. These allow the molds to be securely yet temporarily installed on the backing board, enabling modular molds.
My current method of pressing with two-part molds incorporates two 20-ton shop presses. I use two because this is a simple way to achieve the necessary force to bend the veneers using unmodified, off-the-shelf parts.
To distribute the force and prevent bending the molds, I use some thick 4x6s that I butt-joined with glue. The molds don't attach to these blocks - the blocks just sit between the molds.
Thick wood blocks distribute the load and prevent bending of the thinner 3D printed molds.
Now that's pretty much it! All that's left to do next is glue up some veneer and press some skateboards!