PZT Construction v2Before continuing I exchanged the door panel with the NW bay, putting the door on the N wall. An extra incentive for doing this was the broken nylon screw on the 9x50 finder scope ring, and the bump on my head from an overzealous entrance with telescope on the W side of the pier! This also solved my door clearance dilemma. The funny angles generated by geometry and crooked lumber make fitting the pieces before cutting a necessity.
After fitting the first span I noticed two very well placed supports for a second span with just enough room to squeak it in there. A few more measurements and I determined that the structure on the right was all that was needed to support the dome translated 36" from its nominal spot on the wall. The extra short piece appended on the side (the leftover from cutting the second span) is supported underneath by two 1"x6" deck boards.
The underside of the bench
The two tables assembled and in position.
The dome supported trusses 36" from nominal position. The tapered pier is offset to the south by 6".
No flex in the horizontal member here.
The two contacts points must on either side of the center of gravity at all times!
A little bit of bend, but no break...
A consequence of twisted lumber and no joining member on the ground are some pretty radical angles. Anchor points in the dome wall would be a good idea.
Despite the rickety looking structure, it holds the weight and performs it's function. The most worrisome part of using the table is lifting the dome back onto the walls. While lifting one end the other tends to slip away, and you can end up rocking the dome off one side then the other a few times. Opening/closing the dome is now a bit time consuming since the inner dome clamps need to be removed and dome carefully pushed into position. I am still uncertain of the longer term usability, I feel the concept still needs work!