Bear Coin Bank
Some friends of mine have a daughter and when I see her she's always giving me coins she finds on the ground. Her birthday was coming up so I decided to make her a coin bank that looked like a bear since she likes bears. I wanted to try using the ShopBot CNC with cedar. I like working with cedar and it lasts a long time and has a nice smell. The body is cut from two pieces of 1.75" cedar and then glued together. I used the ULS 660 laser to engrave and cut a piece of scrap plexiglas to make a cover. The cover is held in place by really strong neodynium magnets.
Supplies
VCarve Pro or Carbide Create
Adobe Illustrator or CorelDraw
CNC
Laser cutter
Jig saw
1.75" x 7.75 x 12" cedar board
Wood glue
Plexiglas
1/4" x 2" downcut end mill
1/2" upcut end mill
Sandpaper
Superglue
Draw Your Design As an Outline
I first started off by drawing a bear outline with Adobe Illustrator and included a belly, eyes, nose, mouth and made the legs even on the bottom so it will stand up.
Save Vector for Export From Adobe Illustrator
Next I exported the vector for Export as .dxf, .dwg, .eps, .ai or whatever your software requires. I used .dxf since that's what VCarve likes to import.
Create Toolpaths in CNC Software
Next I imported my .dxf vector into VCarve Pro so that I can apply toolpaths for the ShopBot CNC to cut. I exported each toolpath separately because I like to be able to intervene if something goes wrong during the cutting. I used both 1/2" & 1/4" flat end mills (FEM)
I created the following toolpaths based on my 1.75" x 7.75" x 15" cedar stock
I ran the 1/2" FEM first with these:
-Coin pocket 1/2 FEM cut all of the through to 1.7499" on the front piece of the bear
-Back pocket 1/2" FEM at .50" depth
-Coin slot 1/2" FEM at .20" depth (this is the slot where the coins can slide down)
Then changed the tool out for the 1/4" FEM and ran these:
-Eyes 1/4" FEM cut to .50" depth
-Mouth 1/4" FEM at .50" depth
-Nose 1/4" FEM at .50" depth
-Inset cover 1/4" FEM at .20" depth (this is where the plexi cover will sit just below the surface)
-Outline cut out of each piece 1/4" FEM at 1.7499" depth with 3 tabs on each piece
Set Up Your Material for Cutting
I took my 1.75" x 7.75" x 15" cedar board and clamped it down on the spoil board of the ShoptBot Desktop 24 CNC. I used some clamps that I got from Rockler and put one at the top left corner, lower left corner & right corner. In addition, I also used some wooden clamps that I made on the CNC to push against the middle top and right side using the inset threads on the spoilboard.
Next I calibrated the Z height with the 1/2" FEM and everything was set to go!
Running the CNC
I made all of the 1/2" FEM cuts first and then changed tools to the 1/4" FEM for the remainder. I also double checked all of the clamps between tool changes and re-tightened them just to be sure.
Finishing Up the Parts
Once the CNC is done I used the jig saw to cut out the tabs that I put around the front and back pieces. I used some sandpaper and a bandsaw to clean up any rough edges. I also made a 3D printed dowel sander that I made to get into the smaller areas.
After all the sanding is done I used wood glue and clamps to assemble the front and back pieces and let it sit overnight.
Engraving the Front Cover
Next step was to make a front cover with a name engraved from plexi. I had some scrap plexi from another project so I used a small piece of that for the cover. I used the "belly" shape from the toolpaths to make the outline for the front cover and added "Evie" for the engraving.
I use a ULS 660 laser cutter so I set the cut out to .001 RGB red and the name engraving to black.
Adding the Front Cover
Once the cover was cut out from the laser and engraved I used super glue to attach the neodymium magnets to the plexi cover and the inset.
That's It!
Once it was all done it was time to drop some coins in the slot!