3D Waste to Mobile Art

Since I started 3D printing I've been bothered by the waste produced, for both supports and model revisions. Fortunately I saved all of my waste byproducts and stumbled upon the Teaching Tech tutorials. I print mostly PETG and had a bin with about 30 lbs of various sizes and colors. The big question was, after I recycled the materials, what to do with the end product? We have friends who are cheesemakers, and thought of cheese plates, but the surfaces were a little too irregular. There were thoughts about stepping stones, killer frisbees, weird art pieces and other pregnant ideas. Then I stumbled on the idea of a mobile and began printing parts to support the construction. Since this is more artwork than an exacting build, I won't have a lot of detail about specific sizes or positioning. It's all up to the artist! Many folks say to build a mobile from the bottom up, but I didn't have a workspace to support this, so I built from the top down. The movable posts and arms made it easy to relocate the pieces to achieve balance and esthetics. And, I'm one of those crazy people that doesn't draw out a build-out schematic. I just started printing, cutting and assembling.

Tools:

1. 3D Printer (I use an Original Prusa XL 5h)
2. Gear-reduction grinder (I use the Sun Joe CJ603E) : Note, it is very important to use gear reduced and not high speed
3. Toaster oven (I use an inexpensive B&D)
4. Silicone air fry liner (I use this because of high volume)
5. Heat insert tool (I use the Nut Buster 2000)
6. Drill and assorted bits
7. Oscillating saw or hacksaw (to cut fiberglass rods...wear gloves, mask, etc as fiberglass dust/strands are bad)
8. Heat gun (optional)
9. Rubber mallet (optional)

Materials for mobile

1. Frame hangers (I used these)
2. 24g coated wire (I used this)
3. M4 pan head screws (I used these)
4. M4 Voron heat insert nuts (I used these)
5. Fishing swivels, size 5 (I used these)
6. Heavy duty double eye swivels (I used these or these)
7. Metallic spray paint that adheres to plastic/fiberglass
8. 72" fiberglass driveway markers (I use these)
9. Stainless carabiner
10. 6" Eye bolt

For mobile armature

1. 10' 1.25" gray schedule 40 PVC pipe
2. 10' 1.25" hemlock closet dowel rod
3. 2 45 degree 1.25" PVC elbows
4. PVC cement
5. Waterproof urethane glue
6. Miscellanous screws

Be sure to sort your 3D waste into types as they can have different melt points and not adhere. Some folks like to separate by color, but I prefer the beauty of the unknown.

I use a piece of painter's canvas and a stout rubber mallet to break larger pieces into smaller chunks that will fit in the grinder slot. The grinder slot is about 1.2" x 4.5". Also, a somewhat flat piece that is around 5" to 6" long may 'float' on top of the grinder and not be caught be the grinder blades, so optimal sizes are <4" x 1".

There's not much to see when it grinding, I just dump the plastic chunks into the grinder slot and let it do its work. Quite often I'll re-run the plastic output back through the grinder once or twice. I've found the output averages <1", which is a good size for melting as that size tends to create bigger blobs of color. The ground output will look something like the included photo.

I perform the melting in an outdoor shop where there is good ventilation. I have an inexpensive B&D toaster oven. You can use any as long as the temperature gets to 450 degrees. Even though an oven said it will work to 450, be sure to verify it with an accurate thermometer. Also, ensure the heating happens quickly as some ovens took >20 minutes just to get to 350. It took 3 different ovens to find the B&D which actually heats to 450 (and quickly, less than a couple of minutes.) I like the silicone air fry insert as it has much higher sides than a cake pan, so you can load it down. I fill it nearly to the top. Be sure to shake it a little to distribute the pieces. Sometimes I'll group similar colors to get larger effects. And, transparent colors are great and add visual dimensions in the sun. Usually 30 minutes at 450 is adequate to melt everything down to a reasonably flat top.

At the end of the melt I use heat proof gloves to move the melt out of the oven and onto a plat, heatproof surface. I use a piece of plywood or similar for this. I found the oven rack is not very flat and creates a curved plate when cooled. It will take several hours to cool the piece before it can be removed from the mold. Don't rush this part of the piece may warp. If the air bubbles in the piece don't suit you, then (before you remove the piece from the mold) use a heat gun at 800 degrees to break the bubbles and create unique craters. After removal, I use an oscillating saw and sandpaper to dress the top outside edge of the piece.

I drill a small hole in the back edge of each piece and attach the frame hanger with the included screw. Be sure to size the hole properly or you may crack the piece if you use too much force.

I printed both parts with Prusa PETG. I recommend PETG for all parts as it is more UV resistant and better for outdoor installations. I melt a 4mm Voron nut into the larger (flat) end of the peg. Then I insert a 4mm screw into the nut that is long enough to secure the peg to the fiberglass rod. The vertical armature requires 2 Voron nuts, one on the end (to secure it to the fiberglass rod) and another to insert a screw through the slot to secure the large double D swivel. For this installation I printed 7 armatures and about 16 pegs. YMMV.

For the top I attached a D swivel to an armature with a 4mm screw. I then used the other side of the D swivel to attach to a carabiner with then attaches to the support arm eye bolt. For subsequent armatures I attached an armature to each side of the D swivel. Don't screw them too tight as you want some movement of the swivel in the armature slot. For the pegs I inserted an appropriately sized 4mm screw into the Voron nut about half way. I then used a length of soft wire to connect the smaller end of the peg to the fishing swivel eye. I used the clip end to attach to the D ring on the plastic plate. I made the wires varying lengths to lend some variety. If any plate or doubled arm is > 2lbs you may need to either double the wire or use a larger gauge wire.

There are dozens of different ways to do this. I didn't have access to 45 deg elbows for metal conduit/pipe, so I improvised with 1.25" PVC UV resistant pipe. To make it more robust I inserted 1.25" hemlock curtain dowel into to pipe before assembly. I beveled one end of the dowel so the faces would match at the 45 degree elbow. For explanation I cut 4 sections of PVC pipe and used 2 elbows. Pipe will be number 1 (bottom) to 4 (top) I cut a foot of the bell end of the PVC pipe (part 1) and test inserted the non-bell end into the fence post (with bell end up). I then cut the PVC pipe to three more workable dimensions (yours will vary) and test fit everything. I assembled on a flat surface for alignment. I then cemented part 2 into the bell of part 1. For the next step of part 2 I cut a dowel to size (flush with the bottom of part 1 and extending from part 2), beveled the elbow side 45 degrees and cemented the elbow into the bottom PVC pipe section. I then wetted the beveled dowel ends with water and applied a heavy dose of urethane glue to the beveled face of the dowel in the elbow. I then applied PVC cement to the female 45 elbow and set the PVC pipe into the elbow. Then I dropped the dowel (flat face) into the part three pipe so the beveled face mated with the flat face of the second dowel. After that I drilled and set a screw into the elbow to secure the dowel. The urethane glue expands and will fill the void while cementing the dowels. I repeated the same step for part 3 and 4. When all of this is done I drilled and set a 6" eye bolt into the far end of the pipe/dowel arm. A lot of words, I'll work on a diagram to show assembly.

Now it's just a matter of imagining how you want it to look and operate, cutting the fiberglass rods to length and testing the balance. I usually cut the rods long as I can trim them later. For the top I cut the rod 32", inserted it into the first armature and then added the next armature assembly, the pegs and clipped on the plates. Repeat. For fun I attached 2 pegs together and created a side assembly. I didn't tighten any of the screws until I worked out the balance, there was enough friction between the rods and the pegs/armature that they stayed in place. After all was assembled I decided the orange fiberglass rods detracted from the installation, so I painted them a metallic black.