Tower is almost complete. Got it all together and put on most of the cross-bracing until I ran out of material... AGAIN. The Plastruct ABS angle and T stock comes in sleeves of 7 pieces only. I keep underestimating how much of it that I need. It's also expensive at eight bucks for 7 pieces.
On the tapered side I used the 1/8" T stock, but it looks a little underweight, so on the parallel side I used 1/8" angle stock glued back-to-back to make a large T, but then I ran out so I'll get some more tomorrow and finish it up. I'm also going to adorn it with rivet decals since the gusset plates are big enough to accept them. It's very strong and could probably support 100 pounds in vertical static load. It's only got to hold up an 11 pound Allegheny.
Once again the True Sander really did its thing in getting all the members trued to the correct angles and perfectly square. My small miter box is wearing and the slots are letting the razor saw cut some less-than-90º angles, so I squared everything up with the sander. If anyone out there really wants to get into scratch building I would wholeheartedly recommend getting the three tools from North West Short Line, The Chopper II, The Duplicutter, and the True Sander.
I still have one more side to go with the cross-bracing, then I have to finish up the top mounting area. I was originally going to lay the I-beams directly on the H-beams forming the top, but they are edge up and don't give a lot of gluing surface. I may put a sheet of styrene across the whole thin as a glue base for the I-beams. Onto the I-beams goes another piece of heavy ABS upon which the bridge feet will sit.