Almost There!

Frame is almost done, just need to get the vertical guides and bolt them on. The arm just barely hits the ceiling of the shop when upright, so we wheeled the whole thing outside to get all the lateral supports on. These supports go between the diagonal members and keep the halves of each rail aligned. Fortunately, we were able to move them reasonably close to the center with the arm hitting them. They are circled in orange in the picture below:

We also worked on a little addition originating from the generic F3K Floating Arm design, by adding a small piece between each of the central vertical supports, which the counterweight axle hits at the very bottom of it's motion. This allows the wheels to "pole-vault" over the gap, reducing the stress on the frame and eliminating the quintessential "bump-bump" sound of the wheels hitting the forward rails. The video below shows my colleague demonstrating the wheels appearing to float over the gap due to this addition: