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

Frank Lloyd Wright Desk Lamp - #7 Completing the Base

The maple plywood top that will cover the base comes next.  In the design phase I had two ways of installing the top.  Cutting a rabbit into the sides so the top is flush with the rail or cutting a groove in the side rail so the top is recessed down.  The drawing below shows the two options.  The method on the right is the easiest to do.  If the base is a little out of square then the error is hidden in the groove.  The bad news it would have reduced the size of the column supports.  I could have made the base thicker to compensate but wanted it to be as thin as possible.  That left me with the method on the left.  I could get the thickest column support pieces with the minimum base thickness.  However, because the top butts right up next to the rabbit in the side rails the rabbit has to be cut perfectly straight and the top has to fit the opening exactly.

Earlier on when I the checked glued-up base side rails my diagonal measurements looked just about perfect.  In this case as I was working on cutting the plywood top to fit “just about perfect” turned out to be three hundredths of an inch off.  My fix is to use three playing cards as a spacer between the fence and the top.  Below shows the table saw setup.  The cards push the top away from the fence and I get a straight taper from three hundredths of an inch to zero.

With that cut and using a hand plane to add a little bit of back bevel on the edges the top fit in just right.

The last bit of work on the base top is to cut the hole for the column.  With the top cut to size all I have to do is set the column support pieces in place and mark the opening.   The column has a small (3/32”) lip that will set on the top when the column is installed.  This is what the lip looks like with the column upside down.

I was a little concerned when it came time to actually cut the hole that the thin veneer on the exposed face might splinter.  There is that lip which will cover up some splintering but 3/32” in not very much.  To help minimize that possibility I used blue painters tape to cover the cut lines on the face and reversed the blade in the coping saw so it cut on the pull stroke.  This is what it looked like from the back when I finished cutting and from the front after I removed one of the pieces of tape to see how the edge looked.  Pretty good I think.

It’s now time to do a test fit with all the pieces that go together to make up the column and base and this is how it looks.  The column sits down tight to the plywood which fits tight in the base frame.  I am happy with it so far.

Now that all the parts fit checks out next is to take everything apart and start screwing it together using the pocket screws.  I start by setting the top of the column support flush with the bottom of the rabbit for the plywood top.  After that I clamp it tightly in place then flip the base over so I can install the pocket screws.  Here is what that looks like.  The clamp is to make darn sure that noting moves and stays just where I want it.

With the column support securely screwed in place I put the column in my bench vice then put the plywood base top in and finally put the dry fit base onto the column.  The column gets screwed to the base with 4 screws, three pocket and one straight in.  Process for the three sides with pocket screws is to make sure column is square to base then run the pocket screws in place.   The 4th side does not have a pocket screw but is installed straight in via a counter sunk hole.  Because of the tight space I had to mount the screw driver in a ratchet socket wrench.  It makes more sense when you look at the photo which has the three pocket screws already in place.

The way the column support assembly is built I will have about 5½” of width that will be subject to change in width due to humidity variations.  Not so much here in New Mexico but other places yes. Not taking the potential for expansion is critical.  When wood expands and if nothing has been done

to take that into account something is going to give.  Most likely in this piece it would be the corners of the base or between the plywood top and the base perimeter.  Either would make me very unhappy.  To get an accurate idea of the potential change I use an on-line calculator.  Here is the link: http://owic.oregonstate.edu/wood-shrinkswell-estimator  It says is that in a humid climate in a house with air-conditioning and forced air heating a 5.5” wide piece flat sawn hard maple will experience a width change between summer and winter of about .1”.

Now that I know how much movement I need to allow for I am going to trim off a little from each end of the last spacer and leave an expansion gap between it and the glued-up column support assembly.  This is what the end result looks like.

For now, this finishes the work that needs to be done on the base.  I still have to do the finish sanding and route a slight radius or add a 45-degree break to the sharp edges.  I have not decided which one yet although I am leaning toward the 45-degree edge since there are not any curves on the piece.

Next Up – Spacers & Starting the Boxes

Frank Lloyd Wright Desk Lamp - #6 The Base Part 2

With the perimeter pieces of the base cut and ready I made the corner blocks.  They are made from a piece of scrap squared up then run through the router to clip off the inside corner.  The drawing shows where the blocks go and on the right is the router table setup.

I used the chop saw with a stop block to cut all the blocks to the same length.  The length is set so it is 1/32” shorter than the corner it goes in.  That way I have a little play so it can move just a bit when clamped and not be below the bottom or above the recess for the plywood top.

Now it is just a matter of gluing, clamping and left to cure overnight.  With the glue cured I could take off the clamps and was ready to work on the interior structure.  I did check for squareness by measuring the diagonals and they looked just about perfect.

The process for the column support will be to work from the column out toward the base perimeter pieces.  To start, I cut all the bracing to a height that matches the height of the perimeter piece from the bottom of the rabbit to the bottom of the piece.  With that done I could trim the spacers that go between the two braces so the column has a slight interference fit.  Below shows the column ready to fit and set in place.

Now I cut the braces to length.  They need to fit snugly, not so tight as to bow the sides but just right.  The distance between not fitting, fitting and too loose is measured in a couple of hundredths of an inch.  My method is to set a stop block to cut the piece as close to fitting as I can while being too big.  I then trim off about a hundredth of an inch using spacers.  My spacer of choice for that is a playing card.  They are right at a hundredth of an inch and I can cut to fit the needed application.  In this case I needed two cards to get the fit I was looking for.  From here it’s easy to cut the second piece exactly the same length as the first.

After cutting the long braces I worked to cut the remainder of the pieces that will support the column.  Along the way I made a couple of changes to the supports that I think will work out better in the long run.  Below is a photo of all pieces except one cut and in place along with the column.  The one exception is the far-right piece.  It is just a placeholder.  I will cut the actual piece when all the others are glued and screwed together.

To get the wire out of the chase that runs the length of the column I need to cut an access.  In order to provide this access without getting in the way of the screws that will lock the column to the base I ran it a 45-degree angle.  I started by setting the column in a jig that allows me to drill the hole at the correct angle.  

With the hole drilled I put the column in my bench vice then using a Japanese pull saw cut the waste away and smoothed everything out with a round rasp.

I now just needed to cut a matching slot in the base to finish.  In the photo below you can see my layout lines, the hashed area is where the slot will go. 

Note that it goes through two of the base pieces.  Once again, I used the pull saw cut the waste away then rounded the bottom with a round rasp.  In retrospect, it would probably have been easier to cut a square slot rather than one with a rounded bottom.  Live and learn.  This photo is a little out of sequence as I forgot to take it earlier.  It shows the finished slot for wiring along with the pocket holes drilled.  I will back up and go through the drilling of the pocket holes below.

Before I start gluing the pieces together I needed to drill some holes that will receive pocket screws.  They are drilled in the jig below and have to be done before I glue the pieces together.  The pocket holes allow me to install the screws from the bottom at an angle getting into places that would not be possible otherwise.    For the screws that lock the column in place I needed to adjust the depth the drill cut.  I had to reduce the depth cut as a normal setting would have allowed the screw to penetrate into the wiring chase.  Something I need to avoid.

With all the column support pieces ready, I could work at gluing them together.   Rather than try and glue up all the parts at once and risk of getting one out of alignment I opted to do it in steps.  The outside pieces went together as two separate assemblies then the column block was glued to one assembly.  Lastly to this group the other column block along with the other outside assembly were all glued together.  It’s not hard but was time consuming in that I let each glue-up step set overnight before proceeding.  Anyway, here is what the final glue-up looked like clamped together.

Once the column support assembly was glued up I could do the final fitting of the column to its pocket.  Some gentle work with a rasp gave me the tight fit I wanted and squared the column vertically to the base.   

Flipping the base over you can see all the pocket screws holes in the support assembly that I will use to attach the column to the support assembly and that to the perimeter base.

Next Up – Completing the Base

Frank Lloyd Wright Desk Lamp - #5 Fitting Column Cap, Column Dados & Starting the Base

Next is to make the column cap and the tenon that will tie the two together.   The tenon will have a square bottom to fit in the square chase in the column and a round half to fit into the ½” hole in the top. 

I started with the tenon using a piece of scrap oak and cut it to ½” wide by .53” thick.  I had intended to use a ½” square piece but when I measured the center chase it was .03” of an inch over ½” in one dimension.   I must have had the dado blade set to cut just about .015” deep.  One cut in each board equals the .03”.  With the blank done I marked where the square part ends and the round starts then mounted it in the lathe.  To keep the corners of the square part from chipping off while turning the top half round I used a Japanese fine-toothed pull saw to make a small cut on each of the corners.

It did not take long to turn the square round, measure and fit it to snugly fit in a ½” hole.

The column cap is easy.  The only thing I had to keep in mind when cutting the 2” long cap from the end of my 14” blank is to make sure the grain matched up with the end of the column.  Once cut I marked the center, put it in a wooden hand screw clamp and drilled the hole.

Here are is the long column on the left, the tenon in the center and the cap on the right.  Later the top of the long column will get a ¼” deep reveal cut on all four sides.

Assembling the three pieces and clamping them together shows how the grain flows between the column and the cap.

Laying out all the dados and holes in the column are next.  No two sides have the same arrangement of dados for the baffles and lights.  It is critical to get the layout right.  Either that or I do a redesign should I goof up.

Below is the top half of the column with the light and baffle locations marked out.  The areas with the “X” are where I will cut.  However, before I started to do the actual cutting I marked the faces I will see when making the cut either “Yes” or “No”.  If “Yes” it is set up right and if “No” then it’s not.  The reason it can look wrong is you are looking at the top but making the cut on the bottom so it is the opposite face from what I see that actually gets cut.  Seeing the cut lines on the up face is a powerful visual que that it is OK to make the cut when it may not be.  I know it sounds simple but believe me from experience it’s really easy to do it wrong.

Here is the table saw setup.  The board clamped to the crosscut fence provides backup to the cut so when the blade exits the edges of the piece are not chipped.  The piece of oak clamped to the rip fence is my stop.  Before each cut I push the column up to it for a consistently located cut and clamp it in place with the tall wood clamp on the miter gauge.  I use the tall clamp to make sure the column does not move during the cut.  That would be a bad thing.

After making all the cuts for the baffles I added chippers to the dado to get a 13/16” wide cut for the top of the column.  The final cut is only ¾” wide but I wanted it a little bit over size to eliminate one of the score marks the outside blades leaves.  The outside blades cut a score line at the outside edges that are just a tiny bit deeper than the rest of the dado cut.  That is also why I did not make multiple passes with the 5/16” stack I used to cut the baffle dados.  I need a flat smooth bottom here as it will be exposed.  Here is what the column looks with all the cuts done.

Next, I checked the fit of the cap on the column and made some minor adjustments then sanded the dado and end grain cuts smooth.  Here is what the cap looks like on the column.

Setting the column aside for a bit I worked on the base.  There are quite a few parts to the base, most of them hidden supports to provide the necessary strength for the column and it’s attached parts.  The base is only 1 7/16” deep and the column sets 40” plus above the base.  That sets the stage for a lot of leverage where they come together.   To make sure the column won’t break its connection to the base I need to make it pretty stout.

After getting the perimeter pieces for the base to final thickness and width I cut them a couple inches long mitered the ends and did a test fit to check and make sure the miters fit tight and square.  With everything checking out I set up a stop block on the miter fence and cut the pieces to their final length plus 1/8”. 

Next is to cut the rabbit that the maple plywood top will fit into.  First is to set the width of the cut, in this case about 3/8” and a little deeper than the thickness of the plywood.  That is so when I make the next cut I won’t have to match the corner exactly.  There is another reason that I will go into when it’s time to glue the top on.

Second is to lay the piece face down, set the width of the cut to just over the thickness of the ¼” plywood.  I want it a little thicker so I can use a scraper to bring the top of this piece down to match the plywood exactly.  Plywood is not always the same thickness so I want a little buffer to work with.  I can always shave a little off the top of the perimeter pieces but because the veneer on the plywood is only about .025” thick there little to no margin of error there.

I can now cut the pieces to their final length.  Here is the jig I use to cut the miters.  The reason for the extra 1/8” is because when I butt the piece to be cut against the fence then make the cut I lose 1/8” in length.

Here all four finished pieces are in the framing clamp.  No glue here just checking to make sure all the joints are flush, tight and square.

Next Up – The Base Part 2