Adding the roadbed is actually quite enjoyable for me because I enjoy using my new jigsaw so much. The starting point was my Google SketchUp drawing. I viewed it from above and drew in some rough grid lines. I am sure there was a much more elegant way of handling this but it was Saturday and I really wanted to start cutting.
One of the most important design elements was that the track flowed. In the past I have made the mistake of too often aligning the track parallel to to the benchwork and using very precise radii. I very much wanted to have natural flowing track in this design. I used the drawing to determine the starting and ending width along the 8′ section of benchwork. I also was able to determine the desired amount of arc within that 8′ section. The image below demonstrates how I used a 10′ section of PVC pipe, 3 C-clamps, and some scrap wood to draw a nice sweeping arc along the section. Once I completed the outside arc I used a cheap compass to draw a 2″ wide sub-roadbed along the main line. I then repositioned the clamps to draw the arc along the edge of Camp Two. From this edge I set the compass to 5 and 1/2″ inches to trace the outline for the roadbed within the two track lumber camp loading area.
The picture on the left displays the resulting 8′ section of sub-roadbed. Once the sub-roadbed was cut out, I then traced the outline onto the Homasote. Be sure to consider that the seams of the Homasote and the plywood should not overlap. Make sure that the Homasote and plywood seams are offset by a couple of inches. See the last picture on the lower left for an example.
Once the plywood is cut out then the next step is to cut the vertical supports to support the lumber camp sub roadbed. I ended up with a +6 1/2″ inch elevation for Camp Two so I cut the supports 10″ long. The picture below on the right demonstrates how I connected the next section of sub-roadbed using a plywood splice plate. Be sure to overlap by 3 – 4″ on each side of the joint in order to ensure a gradual grade transition.
One of the major obstacles to complete the sub-roadbed was to connect the corner. I did not have a complete enough SketchUp drawing to work from so I had to go old-fashioned. I used a cardboard template to draw the endpoints. I then went the work bench with a radius template and fitted the curve. The first pass resulted in too drastic of a transition between curve and straight. I smoothed this using a narrow strip of hardboard to create a nice flowing curve of a variable radius.
After the plywood sub-roadbed was completed, I then attached the 1/2″ Homasote roadbed using yellow glue and 1 1/4″ nails from my air nailer again. The picture to the left demonstrates the necessary overlapping joints between the plywood and the Homasote. The final picture to the right demonstrates the nice flowing, curved roadbed I set out to achieve.


That completes this series about building benchwork. Further posts will cover track laying and scenery in this area.









7 users commented in " Benchwork Construction Part 5 – Plywood and Homasote Roadbed "
Follow-up comment rss or Leave a TrackbackExcellent Photos. Really cleared up many questions.
How far apart do you place your risers?
Since I used 3/4″ plywood I went 16″. For 1/2″ plywood I would go 12″.
I just downloaded Sketchup 7.1 and purchased the MissingManual on using Sketchup.
I also would like to know if you created any components that could be shared with other Sketchup users
Rich D
I am about to start putting in risers to create a 2% grade on one of the main lines. Do I need to cut the tops of the risers at an angle or is the slope gentle enough to not make the angled cut on the riser?
I did not cut the tops of the risers at an angle. 2% is pretty gentle. The important thing is that the plywood is spliced together well so that it “flows” over the risers without an abrupt ramp effect. I think I did use 2″ drywall screws in most places though so make sure the screw holding the roadbed down gets good bite in the riser.
Oh and it looks like I missed an answer earlier – I do not have any SketchUp components. I have since switched computers and I seem to have even lost the original drawing.
Thanks again!
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