Its a great time to be a designer, with the ever increasing capability and accessibility of low cost design tools like Fusion360 and more powerful 3D Printers like the Type A Machines Series 1 the tools of creation are getting closer and closer to the designer. A designer can now design, print, and in a matter of hours have a finished product ready for mass production. As materials improve 3D printers can go from machines that make prototypes to machines of limited run production. We've experimented with using 3D printers to create architecture, but there is so much more they can do!
In this instructable I will be going over methods for printing one of our favorite bowls called the Pholem Bowl, then post treatments to turn it into a finished product, and finally exploring ways to cast it into aluminum or bronze.
Step 1: Know Your Printers
There are so many different types of 3D printers out there it can be hard to keep them straight, we use a few different types, and each has it's strengths and weaknesses. To be successful you must match your printing needs to the right printer.
FDM (FFF) Fused Filament: Uses a hot tube to lay down thin layers of thermoplastic
Pros: Great for Prototypes, Many Material Options, Inexpensive materials, inexpensive printer, easy to use, networked
Cons: No soluble support material, limited resolution
PolyJet/SLA Photopolymer: Uses UV cured resin and either lasers or Print heads+lamps to solidify material
Pros: Extreme Resolution, High Speed, Acrylic Like materials
Cons: Extremely Expensive, limited access, not always easy to remove support
Pros: High Resolution, Desktop, Cheaper than an objet
Cons: Expensive material, limited build size, slow, parts require post processing
Powder/Brinder 3D Printing: Uses binder sprayed into bed of powder to solidify material
Pros: Medium resolution, medium speed, cheaper material, interesting material options, full color options
Cons: limited company support, brittle parts, requires post processing
SLS: Uses a laser to fuse powdered material (both Nylon and some Metals)
Shapeways (EOS P300)
Pros: Virtually unlimited by geometry, fast, strong parts
Cons: expensive equipment, expensive materials, long lead time from Shapeways
Step 2: Post Processing Finishing and Dipping Options
One of the most challenging things about Zcorp prints, although they have amazing quality and color they require finishing to become strong. We've worked with many finishing and dipping methods and nothing we've found really strikes the balance between a treatment that is easy, cheap, and strong. Below are some of the things we've experimented with.
x-Wax Dip paraplast plus- This is one of the recommended methods from ZCorp/3DSystems, they even sell a machine that does the dipping for you. Basically this is a heated vat of wax with a basket to dip the part in for 60 seconds then bring it back up. This does work for large and robust geometries (over 2mm) but the parts are still fragile. It's only really suitable for prototypes or models.
x-CA drip/dip infusion-The other recommended method for finishing ZCorp Prints. Taking Cyanoacrylate aka SuperGlue and dripping it all over the print or even dipping the print into a bath of CA. This does work and does create super strong parts. The downside is that this process is incredbily toxic and dangerous- you are working with large amounts of CA liquid and vapor which is both falmmible and can blind you if it gets into your eyes. Also the reaction is highly exotermic so the parts can burn you. Basically avoid this process for all but the smallest/most delicate parts. CA is a last resort.
>epoxy 2 part 7132/2001 or SuperSAP dip/wipe: Our go-to solution for solidifying prints. 2 part high viscosity epoxy is inexpensive enough, wicks into parts, and dries quickly enough to provide a good solution. More on this process in the next steps.
>mixols for coloring: With epoxy you can use Mixols to achieve colors. This is just a resin pigment that is added to the epoxy after mixing.
>polyacrylic dip: A cheaper alternative to Epoxy polyacrylic can be used in a pinch to stabilize parts. It is nowhere near as strong but it is easier to work with, cheaper, and can provide decent results.
>concrete sealer: Many concrete sealers are diluted polyacrylic- the high water content ruined the parts I was working on and never really dried.
-UV resin Dip
Step 3: Testing New Finishes (PolyAcrylic and Concrete Sealer)
When Testing a new finish it's important to isolate your experiments to limit contamination. In this case it means having multiple prints and multiple containers as well as separate vessels for each test.
First prep your work area, make sure you are set up in a well ventilated space and your work surface is protected. Here I'm set up in the Pier 9 Workshop spray booth with paper over the table and the ventilation hood on.
Don your PPE (Personal Protective Equipment) For dipping and post processing 3D Prints you should wear Goggles, Apron, and 2 pairs of gloves, Nitrile over Latex.
After you have your PPE on then prep your workspace, you will need one dipping vat, at least 1 brush, and one landing pad for each separate material you will be using. The landing pad is where the print will go after it has been coated, for this use wax paper. Tape it down with blue tape to keep it from blowing away with the vent.
Place your 3D print into the Vat and slowly pour your treatment over it. Only pour enough that you can tilt the print into it. Use the brush to move the treatment around to all sides of the print. Observe how the print reacts, is it wicking the part, becoming hot, twisting, or becoming weaker? All of these should be noted to assess the quality of the treatment.
After the dip wipe the part with a dry brush to remove any excess treatment, then place it on the pad to dry. Observe it over the next few minutes and remove any drips to ensure a good finish. Come back ever 20 minutes to check the part. Flip the part to ensure even drying.
As you can see in the photos both of the treatments shown failed, although the Polyacrylic fared better than the Concrete Sealer neither was acceptable.
Step 4: 2 Part Epoxy
Follow the steps in the previous stage to prep your work-space, it's even more important with 2 part epoxy since you have a limited pot time. SuperSap will stay viscous for about 20 minutes.
Measure out the epoxy according to the manufacture's ratio. Usually it's 2:1 resin to catalyst. Use a resin cup with disposable liner for multiple batches. If you plan on using a mixol do a normal batch first then add in the mixol. Leave the parts to cure and check them every 20 minutes over the first 2 hours to remove any drips then every hour over the next 4 hours to ensure they come out.
Step 5: Packaging
Once your parts are done it's time to get them ready for sale. Photograph them then design some packaging. Be aware of the target market, in this case we were displaying at Renegade Craft a decidly low-tech venue where vintage trumps 3D printing. We designed the packaging using an Epilog laser to engrave the logo into a craft paper box from PaperMart.
Depending on the product the packaging could have been 3D printed or vacuum formed.
Step 6: Taking It Further
There are so many more ways you can make your designs, here are just a few:
Machining to injection mold
Machining to sand cast
Machining to final product
3d printed mold to injection molded part
3d printed mold to sand casting
Further post processing of 3D printed parts: