Here is the next stage in the modular fiddle yard design: Proof of Concept for the curved boards.

I took my drawings from Autocad, printed them out and stuck them to a scrap piece of 6mm MDF. The plan here was to create a neat template to use a router to cut all the boards from. I used a multitude of power tools to create the first 'rough' template before cleaning it up with a sander. Once I was happy with this I screwed this piece to another bit of 6mm MDF and proceeded to use a router with a bearing guided cutting bit to create the actual template I would use to cut all boards from.

Now that I had my finished template I could crack on with cutting a few test pieces. I used the template to cut the top by simply running the router around the outside of a spare bit of 12mm plywood with a guided bit. The bottom took a little longer as I had to cut the three access slots as well as the outer shape. This is the first time I've properly used a router and I was quite pleased with the results.

Now I had to cut the four uprights to attach the top and bottom parts to. These were simply cut from an off cut of plywood I had from the first two components.

I set about assembling the main structure with all the parts I had cut out of the 12mm ply. I started by marking the centre lines of the uprights on the top and bottom boards. This allowed me to align the uprights up one by one and glue and nail them with some brads. Once I had nailed all four uprights to the top board and turned it over and followed the same process for the bottom board. After I finished this it was apparent that just using the glue and brads created a very strong joint on each part which would likely hold up to transportation. I had always planned to used the nails to hold everything together while I drilled holes for screws and counter sinked them. This will ensure a very strong baseboard which should withstand knocks in the back of my van as well as a few accidental drops.

All that is required now is to glue and nail some flexible plywood to either side of the baseboard to finish it off. The finished product is rigid enough for me to stand on it and light enough to carry with two fingers. I used 12mm ply for this construction which is all I had spare but now the concept has been proven I will be using 9mm furniture grade birch ply to give a strong construction and nice finish as well as shaving a little bit of weight off.

During the process of cutting out the components with the templates, I couldn't resist placing four pieces together to see how it would look. I'm pleased to say it looks just like my drawing

Now I know this concept will work I will finalise some details including having some dado's cut in the top and bottom boards to create a perfectly square and strong joint between the uprights. Hopefully I can build the four curved boards properly in the summer which will give me a nice round test track to run some locos on.

Cheers

Martin