Since I’ve never built a train track, I’m sure that I’ll learn more than I’ll ever wanted to know about train tracks by the time I have it completed. I’m also sure that I’ll eventually look back and realize that I would have done some things differently once I’ve gone through the process.
That said, I plan to research as much as I can to reduce the risk that I’ll have to scrap major pieces of work after the fact because I didn’t have the knowledge to do it right the first time.
So, from my reading, here’s some things to be considered when I design and build the track:
The width between the rails is critical. If the distance between the wheel flanges is 14.5″, then there needs to be another quarter inch added for the distance between the rails so the wheels don’t bind.
The width between the rails in the curved sections needs to be about one eighth of an inch larger to keep the wheels from climbing the rails and derailing.
The curved sections can’t be too tight. The degree of curve is expressed as the distance of the radius that would scribe the curve. From reading, it seems that the tightest curve that the train will be able to handle is about a thirty foot radius. If you think about the geometry, the minimum radius of the curve would have to be increased if the wheelbase of the engine increases or as the track width increases. I’m going with the thirty-foot radius and hoping it works out.
The grade of the track can’t be too steep. It seems from reading that a three or four percent grade is pretty much the maximum that a train should encounter. Because of the slope on the property where the track will go, I may have as much as a twelve or fourteen percent grade. Based on the hill-climbing tests I’ve already conducted, I know the motors have enough power to handle a fifteen percent grade, assuming I can get enough traction to keep the wheels from slipping.
So my general approach to building the track will be to create track sections that can be attached to each other on the track bed. The curve sections will need to reflect a thirty foot radius, so I’ll build some sort of template for those. In addition, I need to ensure that the distance between the two rails is consistent. So I’ll need some sort of template to ensure that the distance between the two rails doesn’t vary as I assemble the track sections.
Once I get some curve sections of track completed, I’ll want to run a test to make sure the engine can handle the curve without derailing. Assuming that test works well, then I can use this approach for the remainder of the curve sections.
I’ll also need to figure out how I want to set the track on the ground. The simplest way would be to just lay the sections on the ground. There may be several problems with this approach, however. The ground is uneven, so the track would be uneven as well. If the track tilts to the side, then the engine will also tilt on that section of the track. Too much tilt and it may fall over. That would be a train wreck. Not good. Also, the grass and weeds will grow between the cross-ties and will be a nuisance to control.
The best approach would be to set the track on a bed of ballast (gravel) to give it the best support and enable me to make leveling adjustments. I don’t want to have to deal with removing tons of gravel at some point in the future, so I’ll start with no gravel and see how it goes. Maybe later, if necessary…
Track construction can be divided into making the rails and making the cross-ties. The rails are made by ripping a 5/4″ decking board into three strips that are equal in width. Deckboard is used, as it is easy to work with, readily available, and comes pressure-treated.
Cutting the deckboard into strips leaves two rails that have the rounded edges, and a center strip that has square edges. I used a router with a quarter-inch rounding bit to round the edges of the center strip. This way, I can get three rails from one deckboard.
The cross ties are made from pressure-treated 2x4s that are cut into two-foot lengths. To ensure that the rails keep the proper distance between them and are firmly anchored to the cross ties, I cut grooves into the cross ties to hold the rails. Since the 5/4″ deckboards are actually one inch in thickness, I needed grooves that were one inch wide and that were spaced the proper distance apart.
My first thought about cutting the groves was to put a dado blade on the table saw. But a little research showed that there are no dado blades for a ten-inch table saw that are one inch wide. This would have necessitated at least two passes per groove, and it would have been difficult to ensure that the groves maintained the proper widths and distances between each other.
My first attempt at actually cutting the grooves was to just make multiple passes over the table saw blade with each pass cutting just the width of the saw kerf. I made enough cross ties to construct an eight-foot section of straight track. But the process was labor-intensive and prone to error. Not a good solution for cutting hundreds of ties.
I abandoned the approach of using a table saw for cutting the grooves in favor of using a router. I found a router bit that cuts a one-inch wide groove with a single pass. This approach looked much more promising.
What I finally ended up doing was to attach several ties with bar clamps so I could cut all of them with a single pass of the router. I also cut a piece of plywood with a width such that it could be used as a router guide and ensure that the grooves for each side of the tie maintained the proper spacing. Here’s what the setup looked like:
Using this approach to making straight sections of rail, I constructed several sections and connected them so I could run an engine test. The test was just to make sure that the engine would track along the rails without jumping the tracks.
There are two types of track sections: straight and curved. While the straight sections are straight-forward (pardon the pun), the curved sections can be a challenge.
My first attempt to making a section of curved track was to lay out a template on the garage floor and use this template to guide the positioning of the cross ties and rails. I scribed an eight-foot long arc with a thirty-foot radius on the garage floor and marked it with tape. This is what it looked like:
Then I positioned the grooved cross-ties on the guides and tried to fit the rails in the grooves, bending them as necessary. I’d get one rail in one of the grooves, and something would pop out of another tie at the other end of the section. I might could have been successful with this approach if I had two dozen hands and the strength of ten men. So I quickly abandoned this and formulated Plan B.
My second approach was to create a jig that would position the rails in a curved configuration and hold them so I could attach the ties. I fastened a set of cross-ties to a piece of plywood so that the rails would scribe the thirty-foot radius. By forcing the rails into the grooves, I could then have them held in place while I attached each of the cross-ties using deck screws. This worked much better, as you can see here.
Each eight-foot section of curved track covers about fifteen degrees of curvature, so it takes twenty-four sections to make the complete 360 degree circle. Using this template, I created all twenty-four sections. Then I created some more straight track sections to make up the gap. Next step was to see if the engine would follow the track without derailing.
I laid out the curved sections on the ground and connected the sections. I also drilled some half-inch holes in some of the ties and drove a length of rebar through the holes into the ground to keep the track from shifting out of position.
Since it would be a constant battle to keep the grass and weeds from taking over the track, I killed the grass along the track bed and rolled out some grass mat to prevent the grass from growing back. I’m hoping this will be enough to keep the grass and weeds from covering the track. Later I’ll cover the black cloth with either gravel or maybe some mulch to give the appearance of track ballast and to hide the mat.
When I ran a test of the engine to see if it would follow the track without derailing, here’s how the test went: