WIth the blocks assembled, time to move on to the end caps.
There will be one for the top side of the lower block and top/bottom for the middle block.

These overhang the veneer surfaces by about 1/4", not a critical dimension, just a shadow line.

3/4" walnut

Box joint blade set used to dado the sides.
1/2" deep for the middle block caps and 1/4" for the bottom block.

The center part fits snugly into the blocks, resting on the corner blocks and hopefully snug to the ends.
I glued on the bottom blocks cap, but still need access to the interior of the middle block.

I used a thumbnail bit to round the edges where they show.

Now to cut the corners of the caps so they are angled and aligned with the blocks corner dados.

Two problems, the blocks are of course angled and the caps extend past the veneered surfaces,

The solution, use spacers DS taped to the faces and use a straight cut bit in the router table.

I removed most of the cap corners with the bandsaw.

Here is the block with the spacers attached. The bit is raised and the fence set to just touch the surfaces on the block

I'll rotate it so the spacers are in contact with the table and fence, then make the pass.


Done!
You can see the thumbnail bit work on the edges of the cap (mineral spirits applied to look for defects)

Same process for the middle block except I used a clamp to hold the caps in place and marked them for indexing into the block.

Time to test fit with the four corner struts.

At least they aligned close to where they were supposed to!

I will leave the top block for later since I'm still thinking about some changes for the shade.

You can see how it all works out on the bottom block. Long screws through the base platform and into the struts and or corner blocks will hold it all in place.

The struts will get glued in place, but I will be dado-ing the strut corners for another level of trim. I'll run #6 screws diagonally through the struts and into the blocks corner braces. The trim will then cover these screw heads.

Getting these blocks positioned lets me measure for the lower set of copper pipes.

3/8" copper pipe, measures to 1/2" OD.

I cut to a bit oversized and prepare to patina.

A saved mailer tube from some Rockler T-Track is perfect, 2-1/2" ID.
To hole the pipes apart for the patina process, I use holesaw cutouts from some 1/2" plywood scrap, 1/2" Forstner bit for the popes to lock in.

These get individually wrapped with paper towels. Wetted down then some rock salt (coarse) and table salt (fine)
sprinkled about.

Then the pipes are rolled up and placed back into the plywood holders.

WallyWorld had a cheap bud vase that could fit down into the plastic mailer tube.

Fill the vase with 10% ammonia, place tube over vase with the cap, then lower in the copper tube rack.
Capped and left upright for a few days of fuming action. The fumes will saturate the paper towel and the towel texture and salt will give the patina some variation.

If the patina sucks, I can just clean it off and try again.