Spline roadbed using hard board...

[rsn48]

I'm building a nolix area with construction under way for the basic area (nolix is just a modified helix).  To simplify matters, the nolix is roughly shaped like an oval in an "L" shape.  So I will be roughly running 80 feet of track (road bed) to gain 20 inches.  There will be some curves in the L shaped oval I have described so I thought perhaps spline road bed might be an answer.  I seem to recall some have used hard board as a spline material so my first question is, has anyone here used this method with hard board.

If you didn't use hard board, what did you use?  How expensive.

I'm interested in spline construction as I'm hoping building the curves as road bed might be simplified.

[Bendtracker1]

I've never used it, but you can check out Jamie's CSX DIXIE LINE

[nscalemike]

I used hard board splines on my last layout and really liked it.  The reason I started over was not due to the roadbed method.  I will say thought if you have a large flat area such as a yard, switching area, or other heavy trackage, it is easier to use sheet stock of your choice.  For a main line run with a spur here or there or a passing siding the spline is hard to beat.  It gives nice curves, controls your elevation changes, and a solid base for your track.

I used 1/4" hardboard I think.  It might have been 1/8".  Either way, around here I can get it for $7 for the 1/8" and about $10 for the 1/4" and one sheet will do lots of splines.  Hardest part is cutting them into 3/4"-1" strips.  Need a table saw and it will make a lot of dust.

For more details check out fellow member Jamie's blog on the CSX Dixie Line http://csxdixieline.blogspot.com/search/label/Roadbed, he provided detailed information that I basically copied. 

Good luck!
Mike

(Allen beat me too it while I was typing!  Check out the site, it's good stuff!)

[rsn48]

Thanks that link was very helpful.  I just quickly went over it and sent the link to a buddy who is helping me, is the hardboard spline topped with cork?

[C855B]

I can't help with experience with it on a layout, but I can advise that you must use carbide-tipped saw blades. If you're gonna cut strips from a sheet, hardboard will dull standard blades into scrap by the fifth or sixth cut.

[rsn48]

So my next question is how to you cut so many pieces of hard board, I understand the carbide Blade recommendation in the above post.  Any suggestions as to how to cut the spline, I have a table saw but it is one of the smaller ones, not a big industrial one, like you would need to use.

[C855B]

While I have a table saw and roller stands for stuff like this, the awkward handling of 4x8 sheets with multiple passes on the long side usually have me looking for another way. My preference for this task would be a hand-held circular saw with a rip guide.

[Lemosteam]

Since you will be likely sanding all of the edges under the track smooth once the splined is assembled, it may be easier to mount a strip of wood to the underside of the platen on a circular saw at the specified width from the blade and use that as a guide to rip off strips.  This solves the sheet handling issue IF you have a table or countertop large enough to support the sheet.  Only the last 6"-8" might be a little difficult because the remaining material will be completely covered by the saw as you go.  Carbide is a must because hardboard is mostly resin with fine wood dust mixed in.  Don't recommend doing this inside the house without a dust collector or facemask!

In a pinch when away from my woodshop I have made a small table saw top larger (to support sheets) by screwing a full sheet of plywood to the top of the table saw surface from underneath with the blade fully recessed.  Raising the blade through the ply will give a zero clearance cut for less chipping.  I support the overhanging plywood with rudimentary legs or a card table.  I sounds dangerous but if stabilized well it's quite safe and effective. 

It is always good to have help when ripping large sheets too so find a buddy and provide a mask.

[mecgp7]

I have never used this method, but do the strips need to be eight feet long? When you buy sheet material most places will actually cut it for you into half or quarter sheets. A 2' x 4' piece is a lot easier to manage when cutting and it will give you 4 foot strips. The big box stores sell the sheets precut in 4x4 and 2x4 sections.

[Bendtracker1]

As mecgp7 said:

A 2' x 4' piece is a lot easier to manage when cutting and it will give you 4 foot strips. The big box stores sell the sheets precut in 4x4 and 2x4 sections.

If nothing else, if all you can get is a 4x8, rip the sheet down to 4 - 12" x 8' rips on your small table saw.  This will make them more manageable so you're not fighting a whole sheet and trying to cut 1" rips.  You still might need some help while cutting the 12" rips.

[davefoxx]

I bought a 4' x 8' sheet of 1/4" Masonite (usually cheaper than buying a precut 2' x 4' or 4' x 4' section) and had The Home Depot cut 1' off one end and then rip the remaining 4' x 7' into three 16" x 7' sections.  I'm using these for fascia, and these cuts gave me the four pieces that I needed for my HCD layout.  Most importantly, these pieces were not only more manageable, but I could get them in the car!  I did not get charged for the cuts.     Unlikely that the store will rip your splines for you, but you could get a couple cuts done to make the sheet more manageable and safer on your table saw.

DFF

[robert3985]

I use splined Masonite subroadbed exclusively for all my mainline subroadbed.  I use 3/4" sanded-one-side plywood for yards and large industrial areas.

Splined Masonite (hardboad) has several advantages over plywood subroadbed.  They are: (1) It's much cheaper (2) the only waste is the kerf (3) when the glue is dry, the splined subroadbed is extremely stiff and structurally strong (4) it naturally forms easments (5) it deadens the "track noise" of running trains extremely well.

The only drawback that I know of is that cutting it is a miserable experience.  You can make it easier to handle the sheets if you cut them lengthwise into four 1 foot wide sheets, eight feet long.

One sheet of true 1/4" Masonite will yield 67 linear feet of subroadbed if you use 5 strips to get a slightly bigger than 1.250" subroadbed width.  That's curved or straight subroadbed...makes no difference.

Really sharp curves demand you use true 1/8" thick Masonite, and that cuts your linear foot measurement in half since you use almost twice as much of the 1/8" thick Masonite as compared to the 1/4" thick stuff.

Last time I cut several sheets into 1" strips, I blew Masonite dust out of my nose for four days.  The last time, I decided to spend mo' money and have my local mill/cabinetry shop do it for 75 cents a cut.  It was worth it to not breathe the dust and the cuts were much more even than my cuts.

Here's a shot of my Taggarts module under construction looking east towards the twin bore tunnel area and the twin Warren truss bridge area.  As you can see, I am using a temporary clamping protocol to mash the subroadbed assembly onto the risers.


Here's a photo of the subroadbed on my two Eliot center siding modules which will support three tracks and a trailing point siding on the east-bound main. Cork roadbed has been laid on the short module in this view.


If you've got DCC sound in your motive power, this subroadbed makes a huge difference in the quality of what you hear since the ambient track noise is greatly subdued.

I lay mine to precisely rendered lines generated by Cadrail so that my curves are neither too sharp or too broad so the spline assembly will fit onto the modules and respective risers without much adjustment.  I print the assembly backwards from its actual alignment since the top of the splined assemble is laid directly onto the paper template (I build it upside down so the top will as flat as possible...even if the splines are slightly different heights).  I drive sturdy finishing nails into the outside line of the template to act as a curving guide, then clamp both Masonite strips and the nail to hold the strips precisely against the nail. 

Here's a photo of that clamping protocol.


Here's a photo of the overall paper template taped to flat 3/4" thick plywood, which are attached to my 6' folding table with grabber screws.


Anyway, it works very well for me, and I applaud the decision of the OP to go with this for his subroadbed.

[rsn48]

So if my tightest curve was 16 inches, do you think 1/4 inch hardboard spline would bend sufficiently, slight larger curves in the visible areas; this would reduce the cutting from roughly one hundred spline (@ one inch) down to roughly 40 - 50 splines, this I think I could handle.

Some one check my mathematical thinking to make sure I'm thinking correctly.  To have one continuous 80 foot length, I would require 10 eight foot lengths of 1/4 inch spline.  Now if I want the width to be one inch, I would then need roughly 40 to 50 assuming wastage, spoilage etc.  Do I have that right?

Rather have some one laugh at me now but catch my error than latter when I' cursing in the train room.

[Sokramiketes]

Bob, I can't imagine how much your modules weigh!   

I've always used 1/8" masonite for spline roadbed.  For single track, I do 5 layers.  However, layers 2 and 4 are just spacers... 1 inch spacers on a 6-8" interval really cuts down on the material used. 

For the double track mainlines on Modutrak, we just run the outside spines and run spacers perpendicular.  This saves a lot of weight and is plenty strong... the spline roadbed is the spine and strength of our modules.

We cap everything instead of trying to keep the top of all the strips level.  A flush cutting router takes the place of any careful measuring when gluing down the cap. 

There a bunch of photos in this article:  http://www.model160.com/n-scale-magazine-features/franksville-wisconsin-project-part-2-laying-spline-roadbed/

[wcfn100]

I would like to suggest that splines are not a good option for roadbed on a grade with curves.  When you bend the spline, you're roadbed will no longer be level, but dip to the inside of the curve.  So for a 90 deg. curve, your tangent track out of the curve with be tilted the same degree that incline was going into the curve.



Jason