I purchased 5mm plywood that I will use for construction. The plan is to cut 1/6 of a circle pieces and laminate 2 pieces to form the helix with each piece being offset by 50% of the other layer. This will allow me to have a roadbed thickness of less than 1/2" and it's my opinion that it will be stronger having 2 pieces laminated as opposed to 1 piece of greater thickness. This also allows me to eliminate spice plates I would use if building this in a more traditional fashion. I realize I could use biscuit joints, but I feel this will be more effective.
I had originally planned to use Masonite. But after trips to my local HD and Lowes, I opted to use plywood. It's three ply layers and I'm hoping it will serve the purpose better and it's less weight than Masonite.
First was to make the template from an old sheet of Masonite. The helix will be 6" wide with an inner radius of 37.5" and outer of 40". I was able to get 13 pieces of the 1/6 of the circumference from a 4'x8' sheet.
I still have more to cut, but this is enough to start the helices. As I mentioned, I will need 3. One will be a double track helix to the 2 east staging yards. The other two will be stacked. One as a double track helix going down to Harbor and Valley staging and the other connecting the main to the upper level. I decided to build all three the same. That will allow me to use the same threaded rods for both helices on the stacked one. I think/hope it will work.
Today, construction began on the helix bases. Good thing I have pavers left over!
More layers tomorrow! And I have more pieces to cut. Also note: I luckily realized that I'll be much better off building the laminated helices in the room rather than in the garage. Good thing, as I'm not sure I'd be able to get it into the room! The diameter is just over 7'.
Benchwork starts next week!
