Transfering the Plan

On both my new N scale Palmer Industrial Park and my older O scale No-Name Industrial Park I drew the trackplan in a cad program (Ashlar Vellum, for reasons I won't bore you with here).  The cad drawing has very accurate turnout locations with point, frog, and center lines marked, and also easements.  The challenge then becomes getting the drawing onto the layout in a form that helps you lay track.  I described the process of getting the full size printout in Mocking up the Palmer Industrial Park.

Once you've got the full size plan taped down to the layout (and in the case of foam, if you're going to paint the foam paint it before you get to this stage) you can transfer the plan from the paper to the layout.  I use a pounce wheel, which is a sharp pointy wheel in a handle.  You can get cheap ones at fabric stores, but they don't have the sharpness necessary to do a good job.  I bought the 3-piece pounce wheel set from Micro-Mark, and I mostly use the largest of the three wheels.

Using the pounce wheel is simple.  Try it out on a scrap with however many paper thicknesses you have to see how much pressure you need to get a good line of dents.  It needs a lot more pressure on plywood than it does on foam.

Using the pounce wheel

At intervals while you're doing the pounce wheeling, take a break (your hand will need it anyway), and very carefully peek under the paper without moving it to make sure you're getting a good line of dents - not too deep, and not too faint.

Once your done, make sure you've got decent lines of dents everywhere.  For laying track, you want the line to be clearly visible between ties and through a thin layer of glue, so you need to go over the dents with a pencil or permanent marker.  If there are places where the dents get a bit faint (it happens), shining a flashlight along the line will bring them out.

A flashlight makes tracing dents easy

A bit of care and patience, and the cad drawing is transferred very accurately to the roadbed.

I've done all the pounce wheeling on the Palmer Industrial Park, but I haven't yet done all the tracing.  The printed plan is now serving as a drop cloth to keep backdrop and fascia paint off the foam, after which it will be discarded and I'll finish the tracing.

I should note that an alternate approach I've seen used on the North Shore Model Railroad club layout's newer areas is to simply glue the printed track plan to the plywood, and glue the roadbed and track to the plan.