Here's a megaproject I made in 40d16 late last year, thought some people might be interested.
Essentially, it's a huge floating oblate spheroid, with a side-to-side diameter of 64 and top to bottom diameter of 32. I made it by building the lower half shell out of basalt, then filling it in with obsidian via a lava/water pumping tower thingy; once the lower half was filled in, I built each outer shell layer then filled it in before doing the next. Lava was supplied by a volcano, and water from an underground river. If anyone wants to build their own fortress in the inside of it, I have a save from when the sphere was done but before I started carving into it (if someone could let me know a decent place to upload it, that'd be great).
As it turns out, I built it a bit too close to the lower edge of the map and one side got a bit squished, but that makes it look more like a death star, so I can't complain.
And, without further ado, pics:
Construction of the shellThe first five levels of the lower shell:
http://imgur.com/2khmI.jpgThe completed lower shell:
http://imgur.com/L0x2G.jpgCasting the lower halfThe obsidian casting tower:
http://imgur.com/0B9hV.jpgThe first layer of obsidian casting:
http://imgur.com/lbva7.gifView from inside during casting:
http://imgur.com/WusNI.jpgIt became apparent that the initial casting tower wasn't up to the job, here's the MkII casting tower:
http://imgur.com/afw20.jpgAnother angle:
http://imgur.com/sAlCU.jpgAnd yet another:
http://imgur.com/OfZwP.jpgSide view:
http://imgur.com/E85um.jpgThe first layer poured with the new tower:
http://imgur.com/4UX6u.gifAnother view from inside:
http://imgur.com/usK8e.jpgTime-lapse filling of the lower half:
http://imgur.com/4TGx4.gifThe last layer of the bottom halfhttp://imgur.com/UtFUy.jpg 18 HalfDone.jpg
http://imgur.com/2Gb7Y.jpg 19 HalfDone.jpg
A bunch of pictures from the half-way pointhttp://imgur.com/eEC1d.jpg 13 HalfDone.jpg
http://imgur.com/vdVFk.jpg 14 HalfDone.jpg
http://imgur.com/6hU9w.jpg 15 HalfDone.jpg
http://imgur.com/jzWjP.jpg 16 HalfDone.jpg
http://imgur.com/ys9v8.jpg 17 HalfDone.jpg
The volcano was full before I started:
http://imgur.com/yQSgD.jpgThere were a few little holes that got missed when building the lower half, here's the contraption I used to help fill them, along with its deconstruction:
http://imgur.com/C7P2n.gifThe top layersAn animation of the first top layer being cast:
http://imgur.com/2TjHr.gifTime lapse of a few more top layers:
http://imgur.com/pDYir.gifA bunch of pictures from when it was almost done:
http://imgur.com/NF6Mr.jpghttp://imgur.com/hgUh3.jpghttp://imgur.com/IfpOS.jpghttp://imgur.com/MPVn6.jpghttp://imgur.com/1zjIH.jpgThe last layer and starting the deconstruction of the casting tower:
http://imgur.com/rLpyE.gifA crude fly-by of the sphere after the casting tower was removed. A couple of holes remain:
http://imgur.com/Y5cAJ.gif