Valentine’s Day is right around the corner. You still have time to make this fun heart-shaped box for your sweetheart.
No need to buy hardware. The lid is held in place by a snug fitting tenon. We’ve provided the .crv files for VCarve users and DXF files, so getting moving on this project will be easy. You need a 1-3/8” x 6” x 6” blank for the base and a 3/4" x 6” x 6” blank for the lid. It’s nice to use a red-toned wood like cherry or bloodwood, but any hardwood will work.
Design and toolpath
Open the .crv files, or…
Create a new file with your workpiece dimensions. Start with the base.
Use a search engine to find heart-shaped clipart. Save the image and bring it into your workspace. Use the Trace Bitmap tool to turn the JPEG into vectors.
Use Set Selected Object Size to make the width of the heart 4”. Be sure to check Link XY so the height remains proportional to the width. Center the heart on your workpiece.
Open Draw Circle and create a 2” circle.
Use the Center Objects tool to center the circle on the heart.
The Center Objects tool relies on clicking on objects in the right sequence. Select the circle first, then the heart, then click Center Objects. This sequence tells the software that you want the circle centered on the heart. If you’re happy with that layout, you’re done.
I wanted the circle moved upward a little, so I selected the circle and used the up-arrow key on my keyboard to nudge it upward.
Toolpaths
Use the 2D Toolpath to cut the outside shape of the heart. Add tabs and use ramps. You need a router bit with enough cut length to cut through the 1-3/8” thick base. I’m using a 1/2" diameter bit with a 1-1/2” cut length.
Use the Pocket Toolpath to hollow the circle to a Cut Depth of 1-1/4”.
Check your work with Preview Toolpath and make any necessary changes.
Make the lid
The heavy lifting is done. All we need to do is duplicate the base to make the lid. In fact, you MUST duplicate the base to make the lid. That’s how you know the outside shape will be the same and the tenon will be in exactly the same spot as the hole in the base.
Leave VCarve with the base open and open VCarve again. Being able to have the software open multiple times is very handy.
Create a new job in the second VCarve file using the lid blank dimensions for your workpiece.
Select the base heart design. Make sure the outline and the hole are selected. Right click, navigate to and click on Copy.
Move your cursor over the new workspace, right click, navigate to and click on Paste.
You now have identical designs in both workspaces.
Use the 2D Toolpath to cut the outside shape. Use the same bit you used for the base.
We need to create clearance so that when we cut the tenon the toolpath goes slightly beyond the outside shape of the heart.
Open the Offset tool.
Select the heart shape in your design and offset the line Outwards/Right 1/4".
Select the circle and the new outside line. Use the Pocket Toolpath with a Cut Depth of 1/4". It’s very important to use the same router bit for these toolpaths as you used on the base. That gives you the best likelihood of a good fit between the tenon and the pocket.
Machine your heart
Mount the base blank on your CNC and zero the X, Y and Z axes. It’s important to make the base before the lid.
Run the pocket toolpath…
…and the profile toolpath. Remove the workpiece from the CNC and cut the tabs to separate the project from the waste wood.
Mount the lid blank on your CNC and rezero the axes.
Run the two toolpaths. Don’t remove the workpiece from the CNC!
Check the fit between the base and the tenon. Don’t sweat it if it’s too tight. We can fix that.
Instead of simply testing the fit you can use digital calipers to measure the inside diameter of the pocket and outside diameter of the tenon. For a snug, not sloppy, fit you want the tenon about .005” smaller in diameter than the pocket.
Correct the tenon
It’s likely that you need to make the tenon a tiny bit smaller. Do this with the Offset tool. If you measured with calipers remember that the amount of offset you use here is half the diameter difference between the tenon and pocket. If you didn’t measure but simply know the tenon is too tight, offset by a small amount, I used .004”. You can always take more off if you need to.
There will be a new circle inside the original tenon, but you’ll have to zoom way in to see it. Delete the outer, original, circle. Recalculate the Pocket Toolpath using the new circle and the outer boundary line.
Recut the pocket toolpath and check the fit. The base should slip over the tenon.
Wrap it up
Use two small pieces of double-faced tape to secure the lid to the base.
Put the lid back on the base and carefully align the two parts.
Sand the heart to remove the bandsaw marks. Having the two pieces taped together guarantees that they’ll be the same shape. An oscillating spindle sander is a great way to work the curves on this project.
Secure the box in a vise and use a 1/4" roundover bit to round over the top corners. Finish sand the box with hand sanding.
Cut a piece of self-adhesive felt to place in the bottom of the box. A fabric circle cutter provides a very easy way to cut these.
Apply a coat of finish and get ready to play Cupid!
