2020 Coronavirus Themed Ornament
As is fit for the year, I decided to make a specially themed ornament to send out for Christmas! This was also my first (successful) project using my new CNC machine (a Shapeoko), though I also used a laser cutter for engraving. Throughout this project I will quickly detail how I created the design, and then show the process that I went through to make the ornament.
Supplies
Consumables:
- Wood, roughly 4"x5"x0.5" (I used Oak and Walnut)
- Wood Stain/Paint (I used Barn Red and Antique White)
- Wood Finish (I used a polycrylic finish)
- Brushes
- String
Tools:
- CNC Machine (I used the Shapeoko)
- Laser Cutter
- Drill
Creating the Design: Inkscape
I started in Inkscape, creating the the basic shapes that I was going to make the ornament out of. Notable elements include:
-The virus, which is based on a number of examples you can see when searching for "Coronavirus Vector" on Google images, just modified to be symmetric.
-The snowflake, which is a basic snowflake shape that I guessed would be CNC friendly.
-The text on each side, "Merry Christmas" on one, and "2020" on the other. I found a cursive font that I thought had a holiday feel, the used the "put on path" function to warp the text along a circle
-And the outline of the ornament, which is basically a circle for the snowflake/virus shape, plus space below for the text
I also used Inkscape to design a basic mold to be made out of MDF that has the function of holding wood "blanks" in a specific spot so that I only need to center the machine once, and then can make 4 of these ornaments at the same time. This also makes it easier to flip over to machine the other side of the ornament.
Attached here is the Mold and design I used for the next steps (you don't need this unless you want to make your own edits.
Creating the CNC File: Carbide Create
Since I have a Shapeoko CNC, I used Carbide Create to make the actual CNC Files. I used Inkscape to "place" all of the ornaments in the mold where I wanted them. Then in Carbide Create, they key elements I made were:
-For both the snowflake and virus side, in the Model tab, I used the shape option to first define the base of the ornament as a "flat" 0.2" thick. Then to give the virus/snowflake shape, I used an angle shape parameter at 35 degrees with a max height of 0.1" and a base height of 0.05" to slightly raise it off the ornament base (this will make it easier to paint later). See the applicable screenshot in this step (pic 3) to help understand what I just described. Each side has a 0.15" feature raised 0.05" off the 0.2" base, meaning the ornament will be 0.1+0.05+0.2+0.05+0.1=0.5" thick.
-Last up, in the toolpath tab, my order of operations were:
- A rough cut with an 1/8" endmill to remove most of the material
- A finish cut with an 1/8" ball mill to make the finer features on the snowflake/virus
- On the snowflake side only (which is the second side I do), I cut out the ornament shape using the 1/8" endmill.
Unfortunately I can't directly upload the Carbide Create files I made, because ".c2d" files are apparently not allowed on Instructables. So you can either recreate it yourself using the vector file I shared the previous step, or as a bit of a workaround, here is a link to Google Drive where you can download the Carbide Create files:
The Mold to Hold the Wood Blanks
The Snowflake Side of the Ornament
The Virus Side of the Ornament
That's basically it on the design side, time to run the machine!
CNC'ing
Because I was making a number of these, my first few steps were actually setting up the process to make the ornaments:
-I started by making a 4 piece tool/mold out of MDF. This is to be used later to hold 4 wood pieces that will be made into ornaments. Holding them in places allows me to do more than one piece, only center the machine once, and makes it easier to flip over to machine the other side of the ornament.
-Next was making the wood blanks, which are ~4"x5"x0.5" blocks. As you may notice in the pictures here, I made a slight mistake when I cut out the wood blanks; I had intended for the wood blanks to be slightly larger than the mold they were to fit in, so that I could hammer them down and maintain an interference fit. I accidentaly did the opposite, and made them a slight clearance fit, meaning that they fit very slightly loosely in the mold. To try to fix this, I wrapped tape around the edges to increase the dimensions and make an interference fit with the mold. This had an 83% (10/12) success rate; I had 2 of the pieces get pulled out (and ruined) by the drill bit. While an 83% will get you through school, I don't recommend that here. Just make your blocks ever so slightly larger than mine. It's frustrating to lose a piece after a couple of hours of work (not even getting into the fact that you have now created a potential wood projectile in your workspace).
-The rest is pretty cut and dry. I cut out one side with a rough then fine pass, flip the pieces over, and do the other side. The pictures here speak for themselves!
The actual CNC files can be made from the Carbide Create files the step before, or the vector files the step before that (just with more work)
Laser Engraving
Using the vector file from Inkscape, I engraved the words "Merry Christmas" on one side of the ornaments, and "2020" on the other. This step was pretty quick (especially compared to the CNC machining the previous step. I used a magnet to hold the ornaments down so that they wouldn't wiggle around from the air blowing out of the laser nozzle.
Touch Ups - Sanding
Things get pretty simple from here on out. Before I started staining I did a round of sanding to get rid of some rough patches from the machining. Some of this was hand sanding, and for some of it I used an abrasive sanding pad(?) attachment on my Dremel.
Staining/Painting
Probably the most exciting step because it finally starts looking like the final product! I used a quick drying oil based stain, one called Barn Red, and the other Antique White (probably don't need to tell you which side each went on). Though other normal paints could work just as well for this.
For each ornament I used a paintbrush to brush on the paint, applying 1-2 layers to each side. Here the small 0.05" raised height of the snowflake/virus feature helps reduce bleeding down to the base of the ornament, which makes things much easier.
Finish
To top everything off I used a satin/gloss polycrylic finish on the ornaments to seal them. For some I used the brush on stain variety and others I used the spray (they're both the same, just different application methods). Part of the reason I used the brush on variety was to see if I applied it before I put on the red stain, if it would help with any bleeding (I couldn't really tell one way or the other).
Drill Hole and Add String
Last thing I did was drilling the hole that the string would go through, and adding that string. After doing this myself, I would recommend doing a couple things differently.
-First, probably easiest during the laser engraving, but I would engrave a mark on where I want the hole to be drilled, to help center the hole when it's actually drilled
-Second, I would probably do this before the staining, as there may be some chipping when drilling (probably dependent on what wood you use). But I needed to touchup the paint a bit after drilling.
And That's It
And we're done! This will be a bit of a memento to "fondly" remember 2020 by in the years to come.
I hope you enjoyed this Instructable! Share a picture if you make one yourself.