Monday, April 24, 2017

Catenary Tower Experiments

5mm magnets countersunk into 3D-printed
catenary tower bases. I found a set of 50
magnets and a drill bit for less than $20
on Amazon.
An unexpected slot of free time emerged this past weekend, which gave me the opportunity to work on Old Line Corridor catenary towers. As reported in my last post, Ed Kapuszinski showed me how he mounted his abandoned catenary towers with rare earth magnets on his Conrail layout. When I first walked in to see his layout, I noticed one his towers leaning at a 45-degree angle; when I glanced at it again a few minutes later it was plumb-straight. He showed me how magnets embedded in the tower bases were stuck to small countersunk screws driven into the road bed. The towers could withstand an errant wrist and be removed for rerailing and track cleaning. I was sold on the idea immediately; here's how I started implementing it on the Old Line Corridor.
A drill stop collar ensured uniform mounting holes for the magnets. The 3D printed towers ain't cheap, and I didn't want to ruin any of them by drilling too deep into the tower bases.  

Remember when I put in HO catenary bridges and made all kinds of jigs? Here's a jig in progress on my workbench. I made this jig to ensure uniform placement of mounting nails into the roadbed.

Mounting nails placed into the roadbed. This is the experiment part: I can't decide which to use. The top is a roofing nail; bottom is a carpet tack. Both have a thin, flat head. The roofing nail  is bright silver, has a fat shank and uniformly flat, square heads. The carpet tack is more svelte, finished  in black and has a skinny shank but but the heads are frequently flawed and not square. Thinking of trying thumbtacks next. Fortunately, all are easy insert and remove from the cork roadbed and foam subroadbed. 
A glimpse of the future: catenary towers magnetically installed on the Old Line Corridor main line. The towers form a visual picket, a compositional rhythm, that transforms the look of the layout. and sets the place: the Northeast Corridor. Some world famous model railroader recently told me he thought catenary was ugly--I respectfully disagree, and I'm excited to have this visually compelling feature on my layout!