I liked the redrawn eggbot but had a minor issue with the pen arm and couldn't make the spring work with my servo. Instead I just went back to the original eggbot design and let gravity do the work. I did this by just taping over the hole for the spring at first, but then decided I wanted a little onshape project to redrew the pen arm...then added a little plateau to the pen arm so I wouldn't need as much servo travel...then added some fillets to smooth out the arm...and well.
Ended up redrawing all of the parts just to round things over and smooth it out. All those sharp edges with eggs just seemed wrong, I wanted something a little more "organic" :D
Everything printed well for me except the back plate which needed a tiny bit of support to keep it from warping due to the rounded top/bottom. I'd also suggest flipping the right support 180 before printing so the build plate side (which comes out a little less rounded on the corners) faces away from the user when assembled.
Onshape document is here: https://cad.onshape.com/documents/774b51d220b28ea0c04bc11c/w/db743683a4ab88a0a85f960f/e/4351b138d554a8d00c2558a4
I still need to clean up the assembly a bit better but not sure when/if I'll get time for that.