A laser cutter will do a good job when cutting felt but there are significant drawbacks to that technique. Synthetic felt will form a small melted bead along the cut edge, and wool felt singes and smells like burned hair. There's also a limit to the thickness of the felt you can cut with a laser. If you have access to a waterjet cutter, it's a great alternative, and can easily cut through thick, dense felt. The finish on the cut edge is excellent.
I stacked and glued the parts I made with this technique to make a vase out of industrial felt. In this Instructable, I'll show you how I made the sliced form and used a waterjet to cut out the parts. Assembly instructions will follow in a separate Instructable.
MATERIALS: ½" thick felt from McMaster Carr, 12" x 60" 3M Prespacing Tape used as frisket 1/8" board slightly larger than the piece of felt
Step 1: Create layout
I designed a vase-like object in Fusion 360, exported as an STL file, and opened it in 123D Make. In "Manufacturing Settings," I created a profile called "industrial felt 60 x 12 x .5" and set the parameters for my material. For "Construction Technique" I chose "Stacked Slices" and played with the Slice Direction until I found an arrangement that looked interesting. Finally, I clicked on "Get Plans" to generate a cut sheet. FeltVase.stl FeltVase.stl924 KB oblong_vase_dmx-1.dxf64 KB oblong_vase_dmx-0.dxf340 KB oblong 2 sheets-1.eps100 KB oblong 2 sheets-0.eps128 KB
Step 2: Prepare the materials
Prepare an 1/8" thick panel two inches larger than the material you're cutting. I used pegboard because there was a good-sized scrap around, but thin plywood would work well and less water would get on the felt. Lay the felt out on this sacrificial substrate. Apply frisket to the entire surface and edges of the felt, and burnish it down with your fingers to secure it to the substrate. The frisket will help keep the felt dry and will reduce swelling of the material near the cut line.
Step 3: Set up the file and the machine
Felt will cut quite easily with just water. If you use garnet in the cutting stream, you'll end up with grit and stains in your material.
Note: The following tips are based on my experience using an Omax Waterjet machine with Omax Layout and Omax Make CAM software. Your set-up may be different with a different machine and software combination.
File Setup:In the Omax Layout software, set the value for all lines to "W" or "Water Only" in the Quality toolbar.You donít need to include tabs in your cuts, since the pieces are unlikely to pop free on their own and would float anyway if this were to happen.Select an appropriate material type in the CAM software. Omax Make doesn't have felt as an option, but "soft wood" worked well.
Machine Setup: Before putting the material to be cut onto the bed, use Omax Make to purge the cutting stream and remove any garnet that may be in the line. Move the head to a position where there are no ribs below. Select "Test" and run "Water only" for 20 seconds or less. Lower the water level. Do not submerge your material! Use clamps on the substrate to secure the felt sandwich to the bed of the waterjet. The thickness of the felt may be inconsistent across your sheet of material. With the cut head about 1/4" up off the surface of the material, run a test of the whole cut path and keep an eye out for the thickest point. Calibrate the height of the head to that. Err on the side of having it too high; the material will cut just fine even if youíre off by a bit more than what is recommended for a harder material.
Step 4: Cut Away!
Step 5: Retrieve your parts
Remove the material from the bed and pop out your parts. LEAVE ON THE FRISKET so you know which side is which. I was so excited about how great the parts looked that didnít do this, and man, did I regret it later.
It took 3-4 days for the felt to dry out in my apartment. This could go faster if you have a nice sunny spot outside. Be warned that wet felt tends to smell like wet animal hair (because it is wet animal hair), but this goes away when it is completely dry.
Assembly instructions to follow in a separate instructable!