Voronoi Clock

I came up with this project after a neighbor of mine gifted me some large chunks of “mystery South American hardwood”. I had a spare ‘clock kit’ laying around, and I also wanted to use Easel’s v-carving capabilities more : Voronoi Clock was born.

And just because it’s a hexagon doesn’t mean the time isn’t obvious: The number of flat sides and pointed vertices still add up to 12 :)

I’m a big sucker for Voronoi Diagrams:
https://en.wikipedia.org/wiki/Voronoi_diagram
Which are great, cellular-looking mathematical structures first created by Georgy Voronoi. If you blew a bunch of bubbles, and they all stuck together: If you took a cross-section of that, it’d be a Voronoi Diagram. And Easel happens to have a generator in it’s App library.

How do you pronounce “Voronoi”? I’ve heard it two ways:
“Voh-roh-noh-eye” (by English-speakin’ folk like myself)
“Voh-roh-noh-wah” (by some French speakers, I happen to like this more)

Be sure you read through all the steps before you begin: I encountered several “gotcha’s” that you should be aware of before you start.

I listed generic ‘mdf wood’ in the BOM, but you’ll need any woodsock measuring at least 8" square, so you can cut the 7" diameter clockface from it. In addition, my stock measured around 1.82" deep, and that’s what the Easel project is currently set to. You do not need something that deep, that’s just what I had : I wouldn’t go less that 3/4" though, or you’ll have a lot of the clock-kit poking out the back (and if you don’t care about that, go as thin as you want…).

You will need to adjust the cut-depth of the pocket in step 4 based on the difference in height between your stock, and mine listed above.

You’ll need a ‘clock kit’ to put in it. This is the exact kit I used:
https://www.amazon.com/Walnut-Hollow-Piece-Clock-4-inch/dp/B000VRRBRC

I used a 90 deg v-bit for cuts 1&2, and a .25" 2-flute upcut endmill for cuts 3&4.

Small saw to cut the tabs.
I used a belt-sander to help smooth the sides after cut, and some 200 grit for other sanding cleanup.

The cut settings in the Easel project are more aggressive than stock : If you have any concerns, set them back to the defaults.

Gotcha #1 – Deep cuts & cutting edges:
When making deep pocket cuts, or outline cuts, it’s important that your bit has a cutting edge for the full height of the stock.

Why? As I’ve learned, if your bit’s vertical axis isn’t perfectly true (and mine isn’t despite repeated calibration), the deeper you cut, the more likely the sides of the bit (without a cutting edge) may press into the stock, building up considerable friction and heat. This can be dangerous. If you have a cutting edge for the full height of your stock, then any friction points will be immediately ground away solving this.

In a nutshell, make sure you have a long bit with a lot of tooth that at least matches the height of your stock.

Gotcha #2 -Sacrificial wasteboards and thick stock:
When making cut-throughs (step 3), I always put a sacrificial piece of thin stock between my wasteboard and the stock I’m cutting: I can then slightly bump the stock thickness in Easel, guaranteeing that I’ll cut all the way through, but not mar my beautiful X-Carve wasteboard.

In this instance, my stock was so thick that I couldn’t use my top-clamps to hold the stock down, and instead had to use perimeter clamps and double-sided tape: Despite my X-Carve being a year and a half old, it just got it’s first mar on the wasteboard: If you want to avoid this, I’d suggest investing in some longer bolts to hold your clamps. I’ll be doing that next…

Gotcha #3 : Correct home
Don’t be a dummy like me and make home on the first cut in the wrong place: As you’ll see from the below pics, for some reason I chose a place on my stock way to high, and almost had the top of the clock extend out the top of mys stock.

Measure once, cut twice? No wait, the other way.

Some gotcha I encountered on this step:

• My stock was so tall, I couldn’t use any clamps to hold it down. Instead, I used a left and bottom perimeter brace, double-sided tape on the bottom of my stock, and side-clamps on the top and left.

This cut uses a 90 deg V-Bit, to cut the outer perimeter/chamfer around the clock. It only takes a few minutes.

When you start this cut, use the “home” from the previous cut: Using the same 90 deg v-bit, it will cut the Voronoi pattern into the face of the clock. You’ll see some redundant cutting around the perimeter, where the chamfer had been previously cut.

This will cut all the way through your stock, leaving little tabs holding the clockface in place. It also drills a hole so you can hang it on the wall.

For this cut, you need to swap from the V-bit to your endmill. This is the process I use in Easel:

• There’s a good chance you’ll need to jog the toolhead away from the stock to make clearance for bit removal: To do this, I mentally track how many “steps” on X&Y I jog it.
• Once I have clearance, I change bits: Note, by jogging the machine the steppers should be powered on, and will resist your tugging, but care should be taken to not move the toolhead while removing the bit. Note, I’ve never moved it myself while the steppers are powered on, but you should still be careful.
• When the new bit is installed, jog the toolhead back the same number of steps to find XY home.
• Before the cut starts, to re-home Z, I jog it down with very small steps while sliding a piece of paper in-between the bit and the stock: When it starts to rub, home Z-home is found.

Like I mentioned in the “gotcha’s” section above, if you’re making a deep cut, be sure you have a cutting edge on the full length of the bit that will be in contact with the stock.

Other Gotcha’s:

• I realized this cut was so deep, that I didn’t have enough z-travel to do it, based on how I had installed my DeWalt611 into the gantry: During the bit swap, I had to loose the bracket around the router, and actually raise it as high as it would go so the bit could clear the top of the stock.
• Based on the length of Z-travel, I realized based on how my dust-shoe is designed, the Z-gantry would hit it at a certain point: Had to remove it, and hold my vacuum line for the next two cuts.

You will continue to use the same endmill for this cut: Now you’ll flip the stock to cut the pocket for the clock kit in the back side. Flipping the stock is quite straight forward:

• Loosen any clamps
• Remove the stock from the wasteboard.
• Vacuum/sweep up any chips on the wasteboard.
• If using double-sided tape, flip to the other side, or replace.
• Flip the stock over, and re-clamp on the wasteboard: You don’t have to worry about being accurate with this: Just make sure it’s generally square.

You don’t have to worry about a perfectly accurate flip because, this cut centers itself on the shaft-hole previously cut: No fancy jigs needed!

When you go to home the machine for this cut, you can use the same technique for Z as in step 3. For X/Y, just visually center it over the center-hole cut in step 2.

Now that the cut is complete, you can use a small saw to cut it free of the tabs holding it to the stock.

I used a belt sander to smooth each of the six sides removing any marks left by the cut.

Lightly sanded the rest.

Applied some Minwax “Natural” stain.

The below pics show pre/post staining & clock installation.

Cut 1 : I used Easel’s “polygon generator” to make a hexgon that would fit my stock. Set the V-bit to cut “on path”.
Cut 2 : I duplicated the workspace of Step 1, and with the hexagon selected, used the “Voronoi Generator” app to create a pleasing pattern. After it was generated, I deleted the hexagon from step 1, from this workspace.
Cut 3 : I duplicated the workspace from Step 1, changed bit types to enmill, and set it to be an outline cutthrough, which would be a perfect perimeter around the chamfer made in Cut 1. I also added the hole that the clock-shaft will fit through.
Cut 4 : At the 0,0 origin, I created a square slightly larger than the size of the clock kit, plus added the little hole so it can hang from a wall.