Laser Cut baseboard construction for 1st Layout

[Jonno]

Hello everyone...first post from me...my 12 year old son is very keen on having a layout and so his interest has become mine. Not being the handiest , I've but together some Grainge and Hodder baseboards in a spare bedroom. I've some pattern makers dowels to align the 3 units and toggle clamps to be fitted to the sides to keep them together. The idea of the layout is that it's semi-portable in that it can be broken down when the room is occasionally required for other duties. 

 

So the question - what is actually the structural point of the cross members underneath the boards? I'm guessing I just glue them in the position shown but they are not tightly braced in, so I'm struggling to see how they serve the purpose of preventing twisting. Should I use shims to eliminate the gaps between the beams and the cross members? The ones in the middle are quite loose, the ones on the edges will need a trim to fit

 

Perfection is the enemy of good enough so I'm not looking for perfection, just practical advice. The idea is to get trains running without too much delay.

 

Thanks for reading, as the build progresses I'm sure this will be the first question of many...

 

 

 

 

[johndon]

I've build 10 of the Grange and Hodder boards and, on mine, found that most of the diagonals actually had to be shortened slightly to fit.  I used PVA as normal to attach them and then, at the ends where they met the cross members, added a fillet of no more nails type glue.

 

John