Thursday, June 6, 2019

HCON Prep: Big Hill Sectional Terrain Panels

 I really like the 2x2 terrain panels I built a few months ago but they do suffer form one issue - their umm flatish-ness.  I wanted to add some height variations and decided to build some modular hill sections.  The height of the hills will be four inches (3 inches from the top of the terrain as standard height of each panel is 1 inch).

The first step in construction was to make the sloped panels, since I'm making three sections, I cut 3, 5 inch x 24 inch pieces of plywood and traced out the dimensions of the slope which is 4 inches flat in from each end and a diagonal line connecting the two points over the remaining  linear 16 inches (4+4+16=24).  The three panels were then taped together and I ran them through my band saw.

 And just like that I've now got 6 perfectly matched side panels.  Well perfectly matched after bit of sanding as band saws are never really precise.  At least the way I use them.....

I then cut the rest of the side pieces out.  Here's the full cut list:

Slope Section
2 x Slope pieces
1 x 4" x 24" 1/2 inch plywood
1 x 1" by 24" 1/2 inch plywood
1x 23.5 square piece of 1/4 inch MDF

Corner section (there will be two of these)
2 x Slope piece
2 x 1" x 24" 1/2 inch plywood
1 x 23.5" square 1/4 inch MDF

 Before proceeding, I traced out the outline of a slope on another piece of plywood in case I want to make more.

Dry fitting the parts for a corner section allowed me a chance to test how the slopes match up - they came out great.  You can also see in the lower left of the picture that the bottoms of each panel have a 1/4 inch square rabbet cut in them that will hold the MDF bottom panel.

I used a router to cut the rabbets.

It's really important that the frames be square and the sides at a 90 degree angle so I broke out the the old Rockler framing squares.  They're a little finicky to use but the extra effort ensures everything is plum.
Here's a picture of the slope section framed and clamped up.
Once the glue on the frames was setup, it's time to fit the bottom MDF panels.  I cut each one to size and then glued them in and added clamps while the glue set.  One can never have enough clamps in a workshop.

I'm only using glue to hold the thing together but with the rabbet joint there is more than enough holding power.  How do I know?  Because a fully assembled panel fell off my workbench and suffered no damage.  I, ummm, meant to do that by the way.....

All three frames fully assembled.

The little cube you see in the bottom right panel are some 1/2 inch pieces I cut to reinforce the joints.  I ended up only using a few of them as the panels were strong enough.
Now I need to install the EPS foam for the ground work.  I had a few sheet of 3/4 inch wide Expanded Polystyrene foam (the stuff with "bubbles") and used that to build up the slopes layer by layer.  I attached each layer with a PVA glue - in this case yellow wood glue).
Once all the layers were built up some weights were added and the glue was left to set.
All three panels with the base EPS foam installed.
The next step will be carving the foam and adding details like rock faces etc.  That will have to wait until another day.  I was pretty tired at this point and decided to come back with a fresh set of eyes (and hands) in a few days.

As of the posting of this update, Historicon is 35 days, 11 hours and 39 minutes away.


caveadsum1471 said...

Nice looking slopes,I like your framing clamps, they look excellent and I'm with you on the number of clamps,more!
Best Iain

Stew said...

Very nice walk through the construction process.
I have high hopes that these will come out looking fantastic. Great job so far. 😀