My Airdyne AD-02 chain guard broke. Couldn't find replacement online. But the part with the mounting holes just fits on a 300x300mm bed. Yay.

I printed it with 0.32 mm layers, and spray painted it with rustoleum hammertone paint. I had it looking good except for one little spot, so I sprayed a little more and then screwed up the hammertone finish. It came through on most of it anyway so whatever.