Prepping the helix.. or the Trouble With Trammels..

I got an email from my friend Jim Fawcett earlier this evening and he was worried that I hadn't put an update on the blog yet, so "was the streak going to end tonight?"  When I got his email I was actually working out some thoughts on how I was going to tackle the helix and I actually came up with a game plan.  So I wrote to Jim and said not to worry, I was actually doing something on the layout...

First, I needed to get dead center on the helix.  As anyone halfway familiar with model railroad helixes know most have a large opening in the middle.  So I needed to put in a temporary beam down the middle and use that to find dead center.  I had a piece of gator foam just the right length (is there ANYTHING it can't be used for? LOL) so I used that. 

Screwing in the temporary beam.

I marked the halfway point on the beam, then I measured with a tape measure across the helix from 3 different angles, and figured out the center by finding the halfway point from where each crossed in the middle. I then positioned the center mark on the beam till that point became the center point of the helix.  I screwed down the beam.  I then fashioned a home made trammel out of yard stick.

A home made trammel was fashioned from a yardstick, thumb nail, and wood screw.

I drilled a very small hole at the 1" mark on the yard stick and another at the 33" mark.  I inserted a large thumb nail into the 1" mark and screwed a wood screw into the 33" mark.

Thumb nail at the 1" mark.

Wood screw at the 33" mark which gives me a 32" radius when I use the trammel.

I inserted the thumb nail part of the trammel into the helix center point and used the screw end to mark along each outer cross braces where the 32" radius will need to be.

Making the mark at 32 inches from center.

After I scratched in a line I went back over those lines with a pen so they'd be easier to see.  Now we know where the backbone braces have to be fastened so that the backbone will be at a 32" radius.

I also tried to find the best place to add the rolling legs onto the helix.  I positioned them in a few different areas and decided on where they will go.  I've toyed the the idea of bolting them to the frame, but I think I'll ultimately screw them on and use angle braces to stiffen them up.  I also came to the realization that if a move ever comes, the helix will need to be cut in half.  I tried to see if the frame would make it up the stairs in one piece... and it wouldn't.  So, most of the layout will be easy to take down and move, but the helix might not make it out alive, though I'm sure with some planning I might be able to get it out in two halves... maybe...

One other thing I did today was I finished off a 1'x4' section I started the other day.



Last of the 1'x4' sections needed.


So considering the day almost went bust layout wise (I spent most of the day putting up Christmas lights) I'm glad I still was able to do some planning and get a few things done.  I'd say it still counts and the Streak stays alive.

What do you think Jim?  ;)