Back Index Next

Laying Out The Screw Holes
The next two steps, laying out the places to drill the holes for the wood screws, and then the holes for the T-nuts, will be the most time-consuming tasks.  This usually involves looking at plans, using a tape measure, a T-square and a pencil - tasks that usually kill any enthusiasm I have for building a module.  However, we'll show you some short-cuts that will produce the same results in a very short period of time. 
We're going to make use of the wood thickness to lay out the location of the screw holes.  Remember that our lumber is ¾" thick.  If we stack 2 pieces together, we have a thickness of 1½".  If we stack 3 pieces together, we have 2¼".


1.  Make a "Screw Marker"
Take one of the pieces of scrap wood.  On the edge that is 4½" wide, make a mark at 2¼", one mark ¾" in from one edge and another mark ¾" in from the other edge.  This is what the piece of scrap would should look like.  Mark ¾", 2¼" and ¾" on the scrap of wood as shown in the photo below. 

2.  Lay out the Screw Holes to Join the End Plates to the End Cross Members
An End Plate will be screwed to an End Cross Member.  The combination of an End Plate screwed to an End Cross Member makes the module rigid, keeps things square, forms a ledge 1½" down from the top of the module frame (which just happens to be the thickness of our styrofoam), and keeps the styrofoam in place. 
Select one of the pieces of wood 22½" long that you labelled as an End Plate and place it flat on your working surface.  Using the 4 remaining pieces, place one piece vertical to the End Plate on your working surface.  Place the other 3 pieces vertical to the End Plate and on the End Plate as shown in the photo below and draw a line along the length of the end Plate.  (This produces a line that is 2¼" from the top edge of the end plate.) 

Remove one of the 3 vertical pieces as shown in the photo below and draw a line along the length of the End Plate.  (This produces a line that is 1½" from the top edge of the end plate.  This distance is the thickness of the styrofoam.) 

You should have two straight lines across the end plates that are 1½" and 2¼" from the top edge.  This is where the End Cross Member will be attached to the End Plate. 
Turn the End Plate end-for-end and repeat the marking process on the other side.  Make sure that the lines on both sides can be joined across the thickness of the wood. 
Select the other piece of wood 22½" long that you labelled as an End Plate and repeat the marking process outlined above. 


3.  Lay out the Screw Holes to Join the the Front and Back Pieces to the End Plate
By joining the End Plates to the Front and Back pieces, we make a square frame for our module. 
Select the piece of wood 4' long that you labelled as the Front Piece and lay it flat on your working surface.  Using 2 pieces of scrap wood, place one piece vertical to the end of the Front Piece and on your working surface.  Place the other piece of scrap wood next to it and on the Front Piece as shown in the photo below.  Draw a line along the width of the end of the Front Piece.  (This produces a line that is ¾" in from the edge of the Front Piece.)

Repeat the process for the other end of the Front Piece.  Turn the Front Piece end-for-end and repeat the marking process on the other side of the Front Piece. 
Select the Back Piece and repeat the marking process for the Back Piece.


4.  Lay out the Screw Holes to Join the Front and Back Pieces to the End Cross Members
The Front and Back pieces will be joined to the End Cross Members.  This will provide a very rigid, sturdy, and square frame. 
Using 3 pieces of scrap wood and the "screw marker", place one piece vertical to the top edge of the Front Piece and on your working surface.  Place the two other pieces of scrap wood and the "screw marker" next to it.  Move the "screw marker" until it is ¾" in from the end of the Front Piece (the line we previously made) as shown in the photo below and draw a line around the "screw marker".  (This produces a line that is 2¼" from the top of the Front Piece.) 

Remove the "screw marker" as shown in the photo below and connect the lines.  This produces a line that is 1½" from the top edge of the Front Piece (the thickness of the styrofoam.) and 4½" long. 

Repeat the marking process for the other end of the Front Piece. 
Repeat the process for the Back Piece. 


5.  Lay out the Screw Holes to Join the Front and Back Pieces to the Middle Cross Members
By screwing the Front and Back pieces to the Middle Cross Member, we  will keep the module frame from spreading in the middle.  It  also serves as a ledge for our styrofoam surface.  We're going to locate the Cross Member in the middle and 1½" down from the top edge of the module frame.

Using your tape measure, locate the middle of the Front Piece, in our case 2', and draw a line across the width of the Front Piece (ie the 4½" width). 
Using 3 pieces of scrap wood and the "screw marker", place one piece vertical to the top edge of the Front Piece and on your working surface.  Place the two other pieces of scrap wood and the "screw marker" next to it.  Move the "screw marker" until the 2¼" mark lines up with the 2' mark we previously made.  Draw a line around the "screw marker".  (This produces a line that is 2¼" from the top of the Front Piece.) 
Remove the "screw marker" as shown in the photo below and connect the lines.  (This produces a line that is 1½" from the top edge of the Front Piece and 4½" long.  This distance is the thickness of the styrofoam.) 

Turn the Front Piece end-for-end and repeat the marking process on the other side of the Front Piece. 
Select the Back Piece and repeat the marking process for the Back Piece.


6.  Locate the Screw Holes
Now that we've got the various boards marked up, we have to locate and drill the screw holes.  This is where our "screw marker" saves a lot of frustration.  Using the "screw marker", draw an "X" at the ¾", the 2¼", and the ¾" as shown in each of the photos below. 



Repeat the above process for the Back Piece.  Note that we don't locate the screw holes for the back side of the Front Piece and the Back Piece.  All we have on the back of these two pieces are lines. 
Mark the surface of the Front and Back Pieces with the X's as "Out" as shown in the photo above.  Mark the top that is 1½" from the top as "Top".  Mark the other side "Top In"
Draw an X on each of the End Plates in the middle (11¼") of the End Plate.  Draw an X 1½" and 6" in from each end of the End Plate as shown below.  Mark the surface of the End Plates with the X's as "Out".  Mark the top that is 1½ inches from the top as "Top". Mark the other side as "Top In"

7. Drill the Screw Holes
We've now located all of the 40 screw holes.  Drill holes using a 1/8" drill bit.  Countersink the holes with a 3/8" or larger drill bit so that the head of the screws end up below the surface of the wood.  Don't worry if you don't drill accurately.  We'll be filling up the screw holes with wood putty. 
Because pin-point accuracy isn't required for locating the screw holes, we've been able to use this "sandwich board" trick of locating the screw holes.  If you aren't comfortable with this method, use your tape-measure, a T-square, and a straight edge to locate the screw holes. 


Believe it or not, we're about 1/3 of the way over the difficult parts of building our module.  But before we start to screw the pieces of wood together, we need to to locate and drill the holes for the T-nuts, plus locate, cut out, and recess the holes for the RJ12 telco jacks.