Frank Lloyd Wright Desk Lamp - #8 Spacers & Starting the Boxes

Now that the base is pretty much done I can start work on the spacers that will go between the column and the box assemblies.  There are two per box so I need to make six.  Earlier on I had rough cut enough pieces to make eight so I have a couple extras in case something goes awry.

After checking for flat and square I cut fresh square ends on the blanks and set up my tenoning jig for a ¼” deep cut.  The setup includes the cardboard shim you can see next to the blade.  I make the first cut without the shim which is what is in the photo then a second with the shim between the spacer and the jig.  I don’t normally use a shim when making tenons but in this case, I needed a burn free surface because the last 1/8” of the cut will be visible.  Tenons are generally buried so occasional burn marks are not a problem.  From experience when making a 1 1/8” deep cut I generally get some blade burn. 

Next is to cut the tab off with the chop saw.  The saw I have has a stop you can set to limit the depth of cut.  This is after the cut and you can see the burn mark and that the two cuts do not make a perfect 90-degree corner.  Even if I had made the second cut a little farther back I still would not have had my sharp corner due to the way the blades are ground.  After cutting the tab off it’s back to the table saw to make the second cut on the tenoning jig with the cardboard shim installed.

To square up the corner I set up the router table with a straight bit and very carefully raise it until it just touches the large face then set the fence to get a 1 ¼” wide face.  This is the setup note the board against the back of the spacer.   It is to keep the router bit from blowing a chunk out when exiting the cut.

All it takes is a single pass across the bit and you get a nice clean square cut.  With that done the last step is to set the table saw for the final width and make the cut.

The three boxes are next.  As you can see in the photo below they are made up of three pieces.  Earlier on I cut blanks for them and had been letting them sit to make sure they were stable.  In selecting the wood to be used I was careful to select boards that had pretty straight grain.  This is because I did not want the grain to a prominent feature. 

The notch in the piece that makes the horns will fit over the spacers caused me some grief.  Simple way to cut those would be to use a stacked dado blade.  However, the set of dado blades I have will not cut that deep.  This photo shows how much short it is.  The carboard piece is a leftover from the prototype but has the same dimensions as the real ones.  I could use the regular table saw blade since it cuts deep enough and make a gazillion passes.  The problem with that is the blade does not leave a flat bottom so I would end up with a sawtooth surface at the end of the notch which would not butt tightly to the spacer.  I could try and clean it up by hand but doubted that I could get it dead straight with perfect corners.  That’s a reoccurring challenge with this piece.  On so many of the joints there is no trim to hide a bad cut so no room for error.  Joints have to fit perfectly or it’s pretty obvious there is a problem.  A simple design does not mean it’s easy to simple make.  On the contrary a simple looking design can require a higher level of craftsmanship.

Here is a board that will make one of boxes.  I have three boards, one for each box.  That’s so the grain will match at the corners and flow from one piece to the next all the way around.  To get a clean, square notch I decided to take a different approach.  I will cut the long pieces notched pieces into three sections, cut the center piece to length, glue them back together and trim to final dimensions.  The theory is that because of the fairly straight grain the joint will be pretty much invisible.  Just like the baffles.  The bottom photo below shows the cuts and dimensions I will use. 

After cutting the pieces to size I glued and clamped them back together.  Here is what the first one looked like, just five more to go. 

I should note that all six are not exactly the same.  There is a left and a right for each box.  Gluing them up all the same would not be a good plan.

After letting the glue cure overnight, I numbered the edge of each piece so I know which one goes where.  Next is to run them through the thickness sander to flatten and get them all to the same final thickness.  Here is one of the sets.  The joints are nearly invisible plus the notch is square and the edges are smooth.

Procedure for rest of sizing is to:

1. Trim notched end to final size.  Because the horns are not all the same length from set to set and the length varies a bit the only constant reference point I had was the inside face of the notch.  To use that face for a stop required more than just a block.  I ended up using a thin piece as the actual stop with a spacer on top of that then a long board with matching spacers at the other end.  A block and clamp held everything in place.  This Rube Goldberg arrangement allowed me to slide the piece in make the cut and remove it without any problem.
2. Cut opposite end square but leave long.  I want to use the extra length to do some test miter cutting and fitting later.
3. Carefully rip to final width taking half the amount to be removed from each side.  If I don’t then the horns will be different width.

Before I started mitering the box ends I needed to make the final adjustments to the spacer so they fit inside the notches.  When I cut the box parts I cut the center piece a few thousands of an inch narrow.  I was not sure how much space, if any, the glue joint was going to take up.  As it worked out two of the six spacers fit and four were too wide.  To trim them I went back to the router table which had never been changed, re-cut the joint and they fit.  I must not have had them pushed up snug against the fence the first time.  Here is what one looks like in place.

Next Up – Baffle Fitting, Completing the Boxes & Gluing in the Plywood Top