Cutting Sub-roadbed curves

[Big_Boy_4005]

I do it all the time, but not for roadbed. I use 1/4" Lauan mahogony plywood for spacing and clamping Gargraves 3 rail O guage track in hidden areas.

I rip a bunch of strips, bundle them together with masking tape, and cut slightly deeper than half way through, spacing the cuts about 1' apart, and then flip the bundle, and repeat the process by offsetting the cut without changing the height of the blade. A radial arm saw is the tool of choice for this process. If you need to go around tighter curves reduce the spacing between cuts.

Of course, as you lay the pieces down, the kerfs will close down on the inside, and open up on the outside. This may make it too difficult to lay your track. But, if you just do it for sub-roadbed, it may be fine.

If it is too rough, take some sawdust and mix it with carpenter's glue, and maybe a little water, and make a filler putty. Let it dry, sand it down, and voila, ROADBED.

Labor intensive, but not expensive. I just paid $8.99 for a sheet at Home Depot.

[michaelstevens]

Paul,

I make my road bed (single or double track) out of 1/4" plywood.
Curves down to 36" Radius can be cut with a new fine tooth skilsaw blade, anything tighter and you need a jig saw.
I shape the shoulders with a rasp, then mark out and cut the 1/2" ply subroad-bed/benchwork -- allowing for column/riser locations if you are bridging over lower level tracks. This time the skilsaw only works for tangents down to about 48" R curves -- be careful -- its probably safer to use a jig saw.

Good Luck !!

[johncolley]

I go around to construction sites and ask them to set aside their plywood scraps for me. when I explain the use for a model railroad most of them will be happy to do it. Why not just lay it flat mark the outlines and saw it with a jig saw? That is the easiest and if you want some bevel use a sur-form rasp. It goes quick and most will be covered with scenery or ballast, right? Save the smooth stuff for parking lots, station platforms, etc.
johncolley tholcapn sailnrail

[bcrews]

This sounds like the spline technique--a sandwich of plywood strips, turned on its side, is used for subroadbed. I've known users of this method to swear by it, and I don't know anyone who swears at it. If you have the equipment to rip the strips, it's not difficult to construct.

Homasote on plywood over an open grid is working well for me so far.

[ndbprr]

Don't see why not it works for me with paneling. I think cork is way to high so I buy dinged and distressed brown paneling from the lumber centers and rip it into 1" strips x 8' long. I get 47 from a sheet so that is 376' of subroadbed for a couple of bucks. Then I stack about half of them on edge and set the radial arm say about 1/4" above the deck and rip them every half inch. They can be bent down to about a 22" curve that way. the other half are used for straight tracks.

[Anonymous]

Since plywood is made up of thin sheets running in opposite directions, I think that even if you get one layer to flex in a given direction, the next layer will not. The spline idea might work though, as plywood can flex "up and down" (when in the horizontal position) and therefore would be ok to flex side to side when on edge...

One thing that occured to me might be to steam bend some 2x2 for subroadbed. Would that work??

Andrew

[ClinchValleySD40]

It would have to be pretty thin plywood. Reason it works with Homasote is that it is soft. With the stiffness of plywood, I don't think it would work past a 1/8 or 1/4 thickness. And if you're going to that much trouble, might as well rip it into strips and use it as splines.

[Anonymous]

A question for all. Has anyone tried cutting curfs in plywood so that it can be formed to the radius of your track curves. I know cutting curfs in Homasote will work, as well as boards. I was just wondering if anyone has tried cutting them in plywood and forming it.
Paul