On April 19th, 2002 we started work on the helix. After spending time building the prototype to get a better feel for what we wanted, and, as seen above, spending some more time coming up with a more thought-through design, we are now starting to build. We are starting with the base frame, which is what the whole helix will be built upon. The helix needs to be removable when we move, so we wanted it to be self-supporting.

The photo below shows two pieces cut out of 1/2" birch plywood. We chose this wood because of its smooth surface and its high quality. It is also resistant to warping. What we cut here is what you can see on the third diagram above (the cutting diagram for the base frame). The photo shows the pieces clamped together on a piece of particle board.


We have labeled the base frame our "ice cream sandwich". The unit has been rotated 90 degrees from the photo above. The three pieces of wood on both straight sections of the oval is what is holding the two plywood pieces together for now. All the various pieces of wood you see here serve two purposes. One is to provide support for the other set of plywood pieces (the wood pieces are the ice cream and the plywood is the cookie). The other purpose is to provide plenty of mounting surface for the vertical stiles that will hold up the luan sub-roadbed boards later.


After the glue dried we put in wood screws for added support and attached the other set of birch plywood boards. After sanding the boards, we are ready for the next step.


Over the past couple of days we have been working on the vertical posts. This photo shows all 16 boards lined up and ready for the router. The boards are 30-inch, 1" x 2" pine boards that are nice and straight.


With lots of clamps everywhere, we cut two 1/2-inch grooves. These will take the base frame plywood boards. We took a piece of straight scrap wood and used it as the router's guide for cutting the straight grooves by hand. The pencil marks seen on the boards are where this guide board is placed so that the router is positioned correctly.


After the two grooves for the base frame were cut, it was time to line up the boards such that they are appropriately staggered. This allows us to cut 1/4" grooves straight across the boards. The grooves are for the luan board sub-roadbed. The boards are staggered so that the grade changes are accounted for.


All the major cutting is complete, so it is time to move the structure into the model railroad room. We have decided to dry-fit all 16 vertical boards to the base frame and then install the luan sub-roadbed, AMI Roadbed, and track as we go. After it is all in there, we will screw the vertical boards to the base frame. The following two photos show the vertical boards installed and the first rung of luan board is in place. We don't have the legs yet so the base frame is supported by four plastic containers (the vertical boards stick out below the base frame by 1/2 inch).




Well, unfortunately the reality of a budget has set in and we will have to pause the helix project for a while. There are a total of 10.5 rungs on this helix (rounded up to 11 because of the lead track needed to the helix). The helix will be double-tracked and we will use AMI Roadbed and Micro Engineering code 55 flextrack. We have measured and calculated a total of 23 feet of track per rung is required. This helix will have 253 feet of track in it when done.

We decided that before we get too much track on the helix, that we first install the legs. The helix needs to be self-supporting, so we are going to install four legs under the base frame. The legs need to be removable so that we can move the helix out of the room. The photo shows the parts used to connect the legs to the base frame. The bolt that has two threads on it will be mounted in the 2 x 2 poplar legs. The square mounting plate will be permanently attached to the under side of the base frame using the four screws shown. The nut will be screwed on to the bolt of the leg (you will see later).


On the bottom of the legs we will install this foot. It has an adjustable range of about one inch. This will allow us to make sure the helix is level. We will not install this part until the whole helix is finished. The legs are 36 inches long, but when the track is all built, they will need to be cut to about 33 inches.