ysbrand and me set up the strongback yesterday.
we started with fixing the short 2"x4" crosspieces you can see to the floor following a centreline we defined with a really tightly pulled dyneema rope.
we used PU-glue to fix the crosspieces to the floor first but to make it a rigid structure we will drill additional long screws into the concrete floor. last thing we want is a moving strongback.
the people who poured the concrete floor did a pretty good job so we just needed a few strips of ply to get everything perfectly level.