This week, I wanted to prototype the swing for my final project. I made a quick model of an indented circular seat with a flat rim in SOLIDWORKS, then used Pathworks 3D to turn it into a toolpath for the ShopBot.
Shopbot Toolpath
I milled the mold for the composite on the ShopBot out of purple foam using a straight-end 1/8" endmill. This was the easiest time I've had yet with getting the ShopBot to work; I'm now comfortable enough with the various softwares and settings to not have to spend an hour+ troubleshooting.
Party hard.
The mold came out relatively cleanly, although the hairs of the vacuum attachment scratched it a bit at the end.
A little rough, but workable
I used a heat gun and a sanding block to smooth out the composite before casting it. I decided to do the swing seat in linen for aesthetic purposes, so I cut circles of linen slightly larger than my mold and cut slits around the outside to accommodate bend. Unfortunately, once I got my gloves on and started mixing and molding, I forgot to take pictures. To start the process, I attached the mold to a board with hot glue so it wouldn't deform in the vaccuum. used paste wax on the foam to seal it. I mixed the epoxy and hardener in a 2:1 ratio, coated and layered all six pieces of linen one at a time, placed mold release and batting over it, then placed it in the vaccuum bag.I thought I was set up for success, but when I came back 12 hours later, I got this:
Whoops
It turns out that I accidentally mixed and matched the types of epoxy and hardener. Unfortunately, I didn't have time to cast it again before class, so instead I'll hopefully be trying it full-scale for my final project.