Cnc Carved 3d Lampshade

I really hated the old plastic lamp we had hanging in our family room, so I made a better one!

• Cnc
• Fusion 360
• 1x6 oak boards
• 1/4x6 aspen boards
• 3" long 1/4" endmill
• 1/8" endmill
• Lamp hardware
• Lots and lots of spare time and patience

I fired up Fusion360 and got started with a 14" square. I made an offset plane 10" up and made a 9" circle. I told it to Loft from the square to the circle, and had the basic shape. After doing a Shell with 1" thick walls, I had a lampshade.

Next I made some cylinders, and used Combine to subtract them and swiss cheese the model. The next step was to slice the model into 5 levels each 2" tall, and slice the 4 sides apart. The 2" height was chosen because that is as tall as I can get through with the 1/4" endmill. I selected each side and did a fillet to get the cool 3d curves between levels.

We now have 20 separate pieces, each exactly 2" tall.

They are holes drilled through the part and into the spoilboard underneath that allow you to flip the part over and get it back into the exact same spot, which is a requirement for all two sided carving. 

Most people put registration holes through a frame, and leave the part attached to the frame with tabs until it's done. I didn't want to go that route, so I decided to put mine through the middle of each part.

I created a sketch on the top of the part, marked the centerline, drew a circle slightly larger than 1/8", and mirrored the circle to the other side.

After extruding the circles through the part, I have 2 holes exactly spaced from center going all the way through the part.

We're going to flip the part over, because cutting it from the bottom first gives me a slightly larger surface area to glue it back down after the flip.

The setup here flips the Z and X axes, and very importantly choses a model box point for origin. Choosing a stock box point instead would result in the second carve being off center.

I've added .4" to each side of the stock, because the bit needs some room to move around. Otherwise the endmill bumps into the stock and then messes up the carve.

I created a 3d adaptive clearing toolpath.

I'm going to use an extra long (3 inch) 1/4" endmill, because it turns out a normal 2.5" long endmill isn't quite enough to cut through 2" of wood.

Under geometry I'm setting rest machining from the setup stock.

The cutting heights go from model bottom to stock top. The retract and clearance heights are both stock top plus 1/8" because I have almost no clearance with the extra long bit.

I'm using a .02" rough stepdown, .005" fine stepdown, and the smoothing option. That will clear out everything it can reach from this side up.

Next I have created a 2d bore toolpath.

It's setup for a 1/8" endmill, and choosing the 2 holes we made for registration.

For the heights, its going to cut from the hole top down to the hole top minus 1/2" because my 1/8" endmill only has 1/2" of cutting length.

Ok for this setup, we can stick with model orientation, and choose the box point in the same corner as the origin.

We're not adding any stock to the model because we've already cleared the space around the part.

So just like the bottom, I'm using a 3d adaptive clearing toolpath with the 1/4" endmill.

This time the rest machining is set to "from previous operation" so it knows what's already been carved.

Heights are the same, with 1/8" for retract and clearance.

The stepdowns are still .02" and .005" with the smoothing checked.

And that should do it for the software side!

I'm using a red oak 1x6, which is of course 3/4" thick.

I cut off two pieces about an inch longer than the piece I'm carving.

The whiter colored wood is aspen 1/4"x6.

I cut two pieces of that at the same length.

I glued the four pieces together, alternating between the oak and aspen.

With two pieces 3/4" thick, and two pieces 1/4" thick, each piece of stock was exactly 2" thick just like the model.

I cut it in half with the bandsaw, and have stock to make two pieces.

I used blue tape and ca glue to hold the stock down to the cnc.

I ran the 3d adaptive clearing path, changed bits to the 1/8" endmill (re-zeroed Z), and then ran the bore toolpath.

The total cut time on the bottom of this piece was 3 hours and 24 minutes.

The registration holes need to go all the way through into the spoilboard underneath, but the 1/8" endmill could only drill 1/2" down. I use an extra long 1/8" bit in my drill to extend the holes from the toolpath down 1/2" into the spoilboard.

Having marked the exact location of the part on the spoilboard, I pull it off the cnc and give it a super fast swipe with a sanding sponge to remove the fuzzies.

Ok! Time for the flip! The carved bottom side gets the blue tape, which gets trimmed up neatly. The holes are poked through the tape. The cnc gets blue tape, and the holes poked through.

I used two 1/8" drill bits to align the holes in the part with the holes in the table. Once I know where the part will contact, I can add a large amount of ca glue, and the part is secured into the exact same position as it was before!

Having swapped the long 1/4" endmill back in, we're up and running the toolpath for the top 3d adaptive carve.

Good news! This one only takes a hair over two hours.

Five and a half hours is reasonable to make a piece, right? Sure.... until you need to repeat this 20 times to make a lampshade.

Does 110 hours of carving time still sound reasonable? No? Well it gets worse if you add another 50 hours for the 11 pieces that didn't turn out well enough to be used in the lamp.

Another super quick swipe with the sanding sponge, and the piece is done!

So... how do I turn this amazing lampshade into a hanging, functional lamp?

I modeled in two crossed bars, that connected to all 4 pieces in the top level.

After adding a center connector, a bulb socket, and a hanging ring, its looking pretty!

Now to make it work, I subtracted the bars from the shade pieces.

Because the cnc is carving top-down, it can't get into the hole...but it did outline the placement of the hole nicely, which allowed me to use the drill press to finish getting the holes to depth.

The shiny brass hardware showed up! I'd ordered the bars a bit long, but after trimming them down a bit it looked perfect!

Let's get this assembled!

I used a picture frame clamp to glue the bottom level together.

That worked great to make sure I had a square base to build on.

I added the pieces for the 2nd 3rd and 4th levels, one at a time onto the base to make sure they were lined up properly.

For the top level, I glued the 4 pieces together with the hardware in the middle, and then glued that down to the rest.

The hardware crossbars are caged inside those pieces, so it cannot be taken apart without breaking the lampshade or cutting the brass bars.

A quick stop on the scale shows around 9 1/2 pounds! Well, with 1" thick oak and brass parts I suppose that's about right.

After a quick hang test to admire my work, I did a bunch of filling and sanding before hitting it with a couple coats of Danish oil.

And, a short 5 months after starting this project I have the most complicated and over-engineered lamp that I've ever seen!

But I have to say that it looks amazing in our family room, and the holes make some really cool spots of light on the ceiling!

This is by far the most complicated project I have attempted on my cnc, but I am thrilled with how it turned out and I learned a ton of things in the process!