I’m part of a mathy family — the kids were happy that I was using the 3D printer to print out a conic sections model that I just whipped together for my wife to use for teaching math.

conic section

I was happy when I discovered that I didn’t have the 5mm rod I thought I did, so I had to chuck some slightly larger aluminum rod in the lathe and turn it down to 5mm to finish the job. ☺

Update: I updated the model so that instead of holes in which to install a separate peg to hold the ellipse on the top of the cone, the peg is printed. It was silly to keep the peg separate in the first place.

(Originally posted on Pluspora)