Nesting Concrete and Plastic Coasters

A set of nesting drink coasters with PLA shells filled with Concrete and Flexible Feet for gripping surfaces.

These are customizable, from the color of the printed parts to the color and texture (via dye and aggregate) of the concrete.

The STLs included are the shells (Coasters.stl), the feet (print 4 per coaster), and a jig that fits over the bottom of your coaster to align the feet. The alignment of the feet is really important as these pieces are what nest inside the lip of the coaster below them.

Print Settings

Printer:

Prusa i3 MK2.5S

Rafts:

No

Resolution:

100

Filament: Prusament, 3D Solutech, Inland PLA, PLA Flexible Filament Grey, White, Green

Notes:

You can print your feet in PLA or PETG, I prefer the TPU-like Flexible Filaments by 3D Solutech, the grip the table and have a little cushioning to them.

Post-Printing

1. Clean up the feet if there are any blobs or stringing that would make it hard for them to pop into place in the glueing jig.
2. Weigh out about 100 grams of cement for each coaster, mix this with water to get to a liquidy consistency but not more than the recommended water ratio, you can add dye or aggregate to the cement mix at this point if you want.
3. Pour the cement slowly into each coaster, shaking them from side to side to help settle the cement. Make sure you are doing this on a flat surface! (I use Rapid Set Cement-all, it keeps it's strength at high viscosity and cures in 30 minutes)
4. Keep pouring until you get the level of the cement flush with the inner lip of the coaster then wait for cement to cure into concrete.
5. Optionally, use a food safe cement or grout sealant for the top of the coasters.
6. One by one, flip each coaster over and clean the back and the top of each foot with rubbing alcohol.
7. Place the glueing jig on top of the bottom of your coaster, it should snap right on.
8. Use Super Glue and dab a small amount around the edges and corners of your feet, pop the foot in place in the jig and give it a bit of pressure. Repeat for all four feet.
9. Wait a few minutes after your last foot to remove the jig and start on your next coaster.

10. Enjoy your coaster set! How I Designed This

Designed all parts in Fusion 360, printed on a Prusa i3 MK2.5S