I started this thread on the PP forums, but wanted to present it to you lot too to draw on your bottomless expertise on all things buildable. And now to the warning: This will be a slooow thread.
The thing is: European cars are (or used to be, at least) small. Too small to be transporting the odd four by four feet V-folded Warmachine & Hordes table. At least my Opel Astra is. Off course the reasonable thing to do would be to give in to the missus and buy that new car (which we probably will before this board is finished) Furthermore, boards are generally allready in place where I'm going, so it's use will be limited. However, I'll still be using an unreasonable amount of time and money to build myself a W-folding board with a proper three dimentional landscape on it.
Your role in this is to play ball with me and tell me when I'm being ridicoulus and point the way forward.
There are a great deal of fine foldable boards out there. Like Alderion's board they are quite thick sturdy structures with regular hinges on each side. It is my impression that the amount of structural material could be cut back quite a bit before sacrificing stability. In other words you could say these boards are over engineered.
First of all the board need to be thinner. This could be achieved by integrating the frame better with the gaming surface using profiled moulds. I'm thinking in the direction of 21 mm high moulds, which with 4 mm plywood in the bottom gives 17 mm left to landscaping. This is a realistic minimum thickness in my view. The greatest challenge (apart from framing the table) will be to get the joints to be as invisible as possible while ensuring that the table can be closed without destroyng the gaming surface.
Using Card Table Hinges/ Flip Over Table Hinges gives you a flush surface both when expanded and retracted. The hinges are felled in on the side of the boards. After recieving Pendrake's advice a year ago six hinges are finally ordered (100 US$ included postal) from Horton Brasses, who reproduces old hardware.
You could off course use Flip Top Hinges/ Counterflap Hinges (often mistakenly referred to as Butler Hinges which only turn 90 degrees). With two floating knuckles they lay flush on the board and turns without interfering with the board corner. If placed on the two joints on each side, they would be visible during gameplay. That could be aestetically interesting on a steampunk inspired table but is not in this case.
For joining I'll be trying out Box Joining or Mitering to ensure a sturdy frame. To avoid visible moulds in the internal joints of the board while maintaining structural integrity, I'll be trying out a 45 degree sloping mould. The outher rim will be 15 mm but will be considered part of the gaming area. For the Plywood in the bottom, I'll be make a 4 mm groove in the moulds, leaving a 10 mm visible frame. This will be my first real venture into carpentry and I'm really curious of how to make the Joining work ...