Today's aim was to put the trackbase on so that I could think about starting to lay track. I started off by cutting out the 3 bits of ply to a shape which I believe is probably close to being right. These were based on the small model i built previously, plus some basic calculations on what was the minimum width for the station passing loops.
As I also needed eventually to add the rest of the scenery at a slightly different elevation, I decided to raise the trackbed up 25mm (for our continental readers who were raised with a sensible measuring system), or 1" (for those who weren't). This is where this method of baseboard construction is worth the work. I riped up some of the remaining plywood into 25mm strips, and then proceeded to build beams as before, with a bit of a difference. The raising beams were made with the blocks protruding at the bottom, and the tops flush. Each beam was made to fit that particular main cross beam, and then was glued in place.
I now had a slight problem to fix. In the previous posts I had described attaching the end plates outside the main beams. This now gave me the problem that the modules were 2 thicknesses of plywood longer than my sheet that I had cut for the track base. This was easily solved by making the rising end plates 10mm higher than the other risers, to account for the 7mm ply plus 3mm for the roadbed (probably to be 3mm cork tiles). It also gave a positive square end to screw the track base to (assuming that the ends of the plywood sheet were indeed parallel to start with)
I managed to get through risers for 2 and a half modules before the brads ran out, which will necessitate another trip to the hardware store for more brads and also some small screws to attack the ply trackbase to the modules.