riogrande5761 I've wondered, why spline? It seems like a lot more work.
I've wondered, why spline? It seems like a lot more work.
It does seem like a lot more work, and that was my orientation when I did it on my second layout. I was surprised, though, at how quickly it went. The thing we all seem to miss is that, if you slat up a sheet of 1/4" MDF, a full 4X8 sheet of it, you'll end up with about forty-five 8' long slats. It might take you a couple of days or four to layeer four or more splines for your main, waiting for the glue to dry each time, but inside of three/four days you have 50' feet of nicely flowing roadbed. The splines naturally curve in any axis as you lay them, provided you take care to position your supporting risers correctly to help orient them according to your plan.
Once I closed my loop, I think inside of three days for the layout pictured below, by far the heaviest workload was forming the terrain over sheets of window screen by mixing and dying successive, many, many, successive 8 cup batches of 'ground goop' using that formula that Joe Fugate shared with us here back in 2004/5. But the mains, fashioned from 5-6 layers of 1/4" X 15/16"X 8' splines went at a torrid pace due to their 8' lengths.
Again, once they're dried, they're amazingly robust and rigid. At that point, the limit to their durability lies in the strengths of the various supporing risers and how they're anchored (normally, top predrilled down into the top of the riser, countersunk enough to bury the head of a simple 1.5" wood screw).
riogrande5761I've wondered, why spline? It seems like a lot more work.
greg - Philadelphia & Reading / Reading
I love spline as it was so much fun to lay/install? It was over way too fast for my liking. You can get 64 linear feet of subroadbed for the cost of a sheet of hardboard, so if you are on a budget you can't beat it. There is not the waste you get with cookie cutter. You do need a saw to cut it up though. I have a table saw and a radial arm saw. I wheeled the radial arm saw outside and used that. I cut the sheets in half lengthwise with the circular saw and fed them through the radial. Don't forget to bevel/taper some of the cuts for the outside pieces.
I used a combination of spline and foam for subroadbed. Next time I will put spline everywhere under the mainline as it is more solid and stands up a little better under the mains. Don't get me wrong, if you want to lay your track on foam go for it, I have had no issues doing just that. The spline just gives that little edge over foam for a subroadbed.
I have added turnouts and sidings in a couple of spots and all it took was to glue some more splines onto the existing ones which took no time at all to do.
For terrain, you can butt foam up against the spline, staple or glue screen, or cardboard strips to the side of it. Choose your favourite method.
Here I had a change of plan in the terrain and glued cardboard to the side of the splines with the glue gun. The double track is splines with spacers in between.
Depending on what tools you have, there is more than one way to build a layout.
Brent
"All of the world's problems are the result of the difference between how we think and how the world works."
Rio Grande. The Action Road - Focus 1977-1983
You can use the usual techniques: a trammel, pencil, on a surface.
The idea of drawing the centerline through the arc you need, and then using dowels or nails driven into the surface at the appropriate distance from that depicted arc that would allow you to form the arc out of splines with the nails/dowels acting as fulcrums should work.
MDF splines worked well for me formed around screws driven into the tops of risers. If you're not fixated on precision here, and are satisfied with an approximation of a specific radius, that's the way to go. Glue an initial three splines on the outside of the screws, lapped and clamped, and when they're solid, another three lapped and clamped to the first splines, but on the inside of them along the curve.
And Brent knows from experience that splines are like concrete. No sproing, unless they come unglued, no give, not in any axis. They're like 3" steel pipe 18" long. Good luck bending it without significant mechanical help.
dknelsonI assume that the finished spline roadbed will actually have some degree of flexibility when completed.
Ya, it will be as flexible as cement.
I put a nail where the centre spline was to go and proceeded to ad the three 1/4" splines to one side, then pulled out the nail and added the other four. Initially I just clamped the uprights to the grid as there was no set distance between them. Once the spline was in place I adjusted the uprights for height to adjust the grade by using a tailors measuring tape to measure the distance between them and doing the math.
I beveled the outside splines for that angled roadbed look, no need for cork roadbed on top if you do that, thus reducing the cost even more.
The curves in my spline were so far above the minimums that I did not need to worry about the radius, just the grade change. I just routed the spline as I went. The bench is 6' wide.
This 4' span without support has been there for 14 years and has not sagged so much as a mm. Someday a bridge will go in there.
I used 1/4" hardboard cut into 1" wide strips. Making them 1" wide makes the math easier when calculating grades. With no roadbed required this is very economical, you can get a whole lot of 1" strips out of a 4' x 8' sheet.
As far as mapping out the radius, when required, I use an old wooden yardstick with holes for the pencil tip at one end and a nail at the other. Close enough works for me.
https://www.youtube.com/watch?v=KbUhA2_F-7M&ab_channel=BATTRAIN1
If you have a suitable surface on which to work, you could simply draw the curve in pencil, then use nails spaced-out along the line to act as a form, then add less-closely-space nails to keep each consecutive strip properly spaced from the previously-applied one.
Wayne
One of the nice features to spline roadbed is that it creates a natural easement curve. But I do see the need to control things so that your desired minimum or "real" radius is maintained. I think the idea of constructing it within a jig makes sense. I assume that the finished spline roadbed will actually have some degree of flexibility when completed.
Dave Nelson
Is the 56" the radius or the circumference ?
I guess that I would build a jig that might be just part of the curve.
Start the build and just move the jig has a section is completed.
Either way that is a big circle!
i need a constant radius dia 56" loop at the end of a 32" wide pennisula. i was planning on building the loop as a spline rather than using up a sheet of foam and dealing with supporting the outer edge.
planning on using 1/8" masonite, probably with softer and thicker material between layers of masonite.
wondering how to maintain a constant radius, assuming a curved wooden template cut at the inside radius for a portion of the circumference
doesn't need to be perfect if the spline is ~2" wide. an accurate center line can be drawn when completed to locate the track