Summer is here and it's time to sit out on the patio and enjoy the stars, and what better way to do it than with a glass of something nice and cold to beat the heat? Ice cold drinks are nice, but the marks they can leave on tables are no fun, so I've laser cut some constellation coasters that are both beautiful and functional. The stars that make up the constellations are cut through while the rest of the design is etched into the wood. I've included a .pdf, .svg. and .dxf file for these coasters that includes all 12 zodiac signs as well as the Big Dipper and Orion. Choose the designs you want and get cutting! Don't have access to a laser cutter? You can find one at your local Makerspace or Fab Lab. Let's get making!
Step 1: Gather Your Materials
- 1/8 inch sheet of plywood of a size suitable for your laser cutter (I used 18x24)
- Soft cloth and water (to make a damp cloth)
- Spray lacquer
- Sandpaper 100,150, 220 and 400 grit
- At least 13 inches of ¼ inch dowel
- Pull saw or other small hand saw suitable for cutting wood
- Vise bench clamp
- Titebond II wood glue
- Scrap cardstock
- Toothpick or skewer for applying glue
Step 2: Prepare the Wood
Prepare the wood by sanding both sides. Start with 100 grit and work your way up to 400. Sand until the wood is smooth to the touch and remember to always sand WITH the grain.
Step 3: Wipe Down the Board
Wet the cloth with a little bit of water and use it to wipe down the board once you are finished sanding. Super fine sawdust can cause fires and additional singing of your wood so make sure your board is completely clean and dry before placing it on your laser cutter. This will lift the grain a little bit, but don’t worry, we’ll do some more fine sanding once the files are cut.
Step 4: Prepare Your Laser Cut File and Send It to the Cutter
Prepare your laser cut file. I’ve included a .dxf .pdf and .svg file that includes a coaster for each of the zodiac signs as well as the Big Dipper and Orion. The name of each constellation is found below the coaster and should be deleted before the file is run or it will be etched into the board as well. The coaster stand is designed to hold six coasters, but you can make as many or as few as you wish. You can also rearrange the star and line patterns to form your own constellations if you wish. Lay out the coasters you want to cut in the format best suited to your laser cutter. Don't forget to include the stand! For this project I made coasters of the zodiac signs of my family members as well as the Big Dipper and Orion.
Step 5: Run the Laser Cut File
Run your laser cut file to etch first and then cut (raster and then vector). We use a 60 watt epilog helix laser cutter and I set the etch to 100% on power and 80% on speed. This gives a dark enough line without producing too much smoke burn. Sanding after the cut is hard (you don’t want to ruin your lines with sandpaper) so you can either mask the etch (I didn’t bother) or make sure the air assist is turned up enough to clear away all smoke.
Step 6: Prep Your Coasters for Lacquer
Remove your items from the laser cut bed and give them another quick sand with the 400 grit then wipe them down with the damp cloth and let them dry.
Step 7: Cut Dowels for the Stand
While your coasters are drying, prepare the dowel for the coaster stand. Measure four 2 ½ inch lengths. Clamp your dowel to a table and cut off each piece taking care to make your cuts as straight as possible. Do not leave too much dowel hanging over the end of your workspace while you cut or it will snap and you will end up with rough edges. Sand the tops of the ends when you’re done cutting if you like.
Step 8: Lacquer All Parts
Next it’s time to lacquer! Put on your gloves and once the coasters have dried take them, your coaster base and dowels to a well ventilated area (preferably free of wind and dust) and give them a coat of spray lacquer. Wait fifteen minutes (or until the lacquer is dry to the touch) and flip them over and coat the back as well. Spray lacquer is great because it doesn’t require sanding between coats (particularly for a small project like this) so when both sides are dry go ahead and give them a second coat. This will waterproof your coasters and give them a nice shine as well. When everything is dry it’s time to glue up the stand.
Step 9: Assemble the Base
Put a small amount of glue on a scrap of cardstock and use the toothpick or skewer to apply glue to the sides of the end of a dowel. Press the dowel firmly into a hole in the coaster stand and repeat for the other three dowels. Wipe off any excess glue with a toothpick (wood glue dries yellow and doesn’t look too pretty).
Step 10: Wait Till Dry and Enjoy!
When everything is dry, stack up your coasters in the stand and admire how lovely they look! Or better yet, pour yourself a drink and test them out. Enjoy! If you liked the Instructable please vote for it in the Space contest! Thank you!