Mister Data's Free-mo Trestle Module Build

In March of 2014 I started on my 'chainsaw' Free-mo module project. It is going to be a module featuring a plate girder bridge and a small cut through a hill as found on the old Southern railroad line (now part of Norfolk & Southern's Chesapeake and Western division) that runs behind my house.

One of the goals of this Free-mo module is to explore various building methods that will result in, what I feel, "strong enough" modules to withstand frequent moves in cards and the rough handling at shows. I want the module to be lightweight, yet sturdy enough. I also want to use this module to get a feeling of making scenery: Virginia style hills, rock faces, grass, static grass, trees, scratch build bridges, weathering rails, weathering railroad ties, ballasting and anything else that comes along.

As you can see, a true chainsaw type goal for this module build. Follow along!

-Yaron Bandell.

The basic sides of the module are made from 1/2 inch birch plywood while the endplates have to be made from 3/4 inch thick material (birch plywood in my case). All is held together with Gorilla glue and some #8 woodscrews.

A test fitting of the leg support brackets in 2 of the corners

This is what the module should look like (seen from the top) with all 4 leg support brackets glued in place.

A closeup of one of the leg support brackets I envisioned, completely madfe out of 1/2 inch birch plywood.

A different angle of the leg support bracket

A pair of mirror image leg support brackets

Time to attach the leg support brackets. You can't have enough clamps ever: of course I ran out, so I had to do them in stages of 2 at a time.

Here I'm glueing in place some 3/8 inch dowels as the support for the 1 inch foam top. All sides of the module will get these dowels glued in place to help adhere the foam to the sides and endplates of the module.

The vertical roadbed support structures, made from 1/2 inch birch plywood, were glued in place. The top vertical support has a 1/2 inch cut out over a length of 17 inches where the bridge will be.

The short piece of roadbed on the far end of the module has been glued in place already, now it's time to glue the final piece of roadbed to the vertical support. Roadbed is made of, you guessed it, 1/2 inch birch plywood as well.

A closeup of the "long" stretch of roadbed being clamped in place while the glue dries.

This is the side view of where the bridge will end up. I compressed the bridge length a bit by making my bridge use only 6 spans versus the prototype using 7 spans of around 20 feet each.

Closeup of the left side of the bridge.

Closeup of the right hand side of the bridge.

I shouldn't forget to post a prototype picture of the bridge which I'm going to try and scratch build. Don't mind the quality of the pictures, it was cold outside, so I didn't want to leave my warm car. Call me lazy, at least I'm not armchair modelling anymore :)

A Google maps overview of the trestle and surrounding area.

Closeup picture of the bridge #1.

Closeup picture of the bridge #2.

Closeup picture of the bridge #3.

Closeup picture of the bridge #4.

Closeup picture of the bridge #5.

Progress up to April 4, 2014:

The whole module is glued togetheer, including the road bed support

Closeup of the leg support pocket, with a 1x2 leg inserted.

The leg fits in the pocket, but it's kind of tight. I'll need to widen the pocket just a bit to account for expansion of the leg's wood.

Closeup of one of the foam support ridges, made from 3/8 wooden dowels.

And here it is, the module on its own legs. Second part of the legs will be cut soon and 4 inch leveler plus bracket will be attached. Plan is to allow the module to be at NMRA 40 inches nominal height, all the way up to Free-mo maximum nominal height of 62 inches. By allowing the two pieces of the leg to be adjusted up and down in 3.5 inch increments combined with the use of the 4 inch leveler feet, the module should be able to reach any height between 39 inches to 63 inches floor to top of railhead. All I need is a few minutes worth of time on a drillpress :)

Since a picture says more than a thousand words, here a drawing of the NMRA verus Free-mo module height. All it is missing is the distance / positioning of dril holes to keep the two leg halves together.

Text, images (except Google map image) and code all ©opyright 2014 Yaron Bandell.

ral bridge segments needed. This is what the prototype bridge sections look like:

The prototype has a total of 7 of these sections. I might only do 5 or 6 due to space constraints on the nearly 4 foot long module. After about 2 hours struggling with 1/4 inch styrene I-beams and some rudimentary tools, it was done. It wasn't as neat as I wanted it to be: better tools and realizing I needed them while building it made me less patient and the result shows it:

So while being a bit disillusioned of my scratch building skills, it hit me: why not abuse the wife's Silhouette Cameo? We've had the thread on MRH about the Cricut Explore and people mentioning the Silhouette Cameo as less restricted from a "print" perspective. The Cameo can cut thin styrene sheet of up to 0.015 inches and makes scoring lines on 0.02 and 0.04 inch thick sheets. It would also allow me to make as many bridge sections as I'd like. Since I have no sheet styrene I could simply do some testing on 65 lbs cardstock. Well, an hour or so later in their designer software, I had a first drawing up and ready to print and my funk of disillusion was nowhere to be seen. This is what the design looks like in the Studio Designer software:

After hitting 'Send to Silhouette' it took about 10 minutes for the cutter to do its job on the cardstock. Cutter was set at '3', thickness at '33' and speed at '1'. This is what the cut out design looks in cardstock like before popping the parts from the tacky mat:

Yes, that cardstock was "borrowed" from the wife scrapbooking supplies ;) At least this bridge section will be easy find when it somehow gets misplaced.

Depending on the settings on the cutter, the parts will pop right out or might need a little convincing to detach from the rest of the cardstock. If the parts were completely cut from the cardstock, parts may stay behind on the tacky mat when you pull the mat away from the cardstock. The various scraper and hook tools for the Cameo will help you remove those parts from the tacky mat, especially if your mat is new it is very tacky. We used a hand towel on the mat before using it for the very first time to make it less tacky: just dab the towel on it a few times and you feel the tackiness get noticeably less. The tackiness of the mat is now such that it is possible to simply peel them off with a finger nail if needed.

Putting the prototype together with Elmers white school glue gave me the following result in just about 10 minutes of assembly time. Except for the top and bottom, all parts were tripled up to get some oompf to the bridge section. This is what it looks like compared to the styrene scratch build part earlier:

A different angle of the completed part:

And one more (final) angle of the part:

For a first try I think it was a very successful experiment. There will be some things that I will change when it is time to cut the parts from 0.01 inch styrene sheet though: the height and width of the tabs should be decreased to match the material thickness better. I also think I'll create some tabs on the cross members for more easily positioning them. The extra tabs should ensure they will be at a perfect 90 degree angle with the bridge sides. The length and width of the bridge section likely needs to be altered depending on the actual length of the Central Valley bridge ties I intend to use. The prototype has a total of 14 ties per bridge section and I'd like to keep to that number of ties per bridge section.

Now it's waiting for some 0.01 inch sheet styrene to arrive and do tests on that instead of cardstock.

Text, images (except Google map image) and code all ©opyright 2014-2015 Yaron Bandell.