Behind the Scenes: Using ZCorp
Here's the first in a series of articles I
plan to write about 3D Printing. The problem with most 3D
Printing literature is that they're full of marketing crap that don't
tell you the truth about the machine. Building Ownage, I've spent most
of my adult life (haha don't worry.. I'm not that old) working with
these machines so I'm happy to pass along what I know. I hope the guild of printing magicians don't come after me because of this! Trade secrets!
Today I'm gonna tell you about ZCorp. ZCorp produces the Z310,
Z450, Z510, and Z650 3D Printers. These are 3D Printers as opposed to
Rapid Prototyping Machines. What is the difference? The running joke
answer to this question is, "Oh about $100,000." Truthfully, the
difference between an RP machine and a 3D Printer is not that big. 3D
printing describes machines like Stratasys FDM, ZCorp, and Objet that
use a printhead similar to an inkjet printer. Because it uses inkjet
technology, these machines are much cheaper than RP machines like SLA
and SLS. In the future I will describe each of these in detail.
When it comes to ZCorp, the basic process is that the machine has
two buckets of powder next to each other inside the machine. One
bucket holds the finished print. The other bucket holds extra powder.
ZCorp machines use a starch (flour) based powder that the printhead
glues together on each pass while depositing a drop a color on the
outside layers. ZCorp is one of two 3D printers that can print in
color (the other being the Objet Connex500). But the ZCorp machines
are the only machines that "kinda" prints in full color. The machine
prints about 1 inches high an hour. When the print is done, it needs
to sit in the machine for a few hours while the machine adds heat to
bake the glue that holds the model together. After that, because the
model is EXTREMELY fragile, you'll need to manually harden the model by
dropping/spraying super glue over the entire surface of the model.
This is extremely boring and time consuming.
The main benefits with ZCorp are that it prints fast, cheap, and in
color. The material is the cheapest coming in at $2 a cubic inch.I
have a lot of complaints with ZCorp. It's really not that bad when you
print big things. But it SUCKS at tiny details because the entire
surface of the model is bumpy like sand. This is of course a side
effect of using powder as the print material. But if you're printing
rock or stone-type figures, it might actually be a good thing!
The post-processing with the ZCorp machine is the most time
consuming of all machines I have used over the last 6 years. The
standard method is what I stated above, to cover the model with
CyanoAcrylate (superglue) and harden the model. The problem with
superglue is that often times you don't get uniform curing.
CyanoAcrylate reacts with water moisture in the air to cause a chemical reaction and bond. Many times if the super glue is applied too thick,
and there is too much water (humidity) in the air, the glue will frost and turn
your model white. This is called frosting or blooming. You'll see
this on a lot of figureprints.com
models. It also affects how the models look in photos. With any form
of lighting or flash, the models will look washed-out and terrible.
ZCorp sells an additional way to post-process figures. It's a
bucket of liquid wax that you can drop the models into. It's a lot
easier to do it this way.A lot of people ask me, "How does
Offload Studios post process their ZCorp models?" Offloadstudios.com
is famous for doing the best work using the ZCorp machine. I'm
impressed with the surface finish they do with ZCorp. Makes me want to
play with ZCorp more. But Offload says their methods are proprietary
trade secrets. Haha, I wouldn't want to mess things up for them. But
If you gave me 30 seconds with an Offload printed piece, a saw, and
some smelling I could tell you exactly what they do. Aside from that,
I can only guess based on experience and pictures. For larger pieces,
it looks as if they do some surfacing to smooth out the plastery finish
that ZCorp has. Because superglue does not sand well, my guess is that
they use a sandable, clear resin such as a thinned down, polyurethane
glue or epoxy. Or maybe they just use the wax bath. I believe it
might be possible to put the model into a pressurized tank full of the
resin or wax of your choice. This will quickly infiltrate the model
and make it super strong. It's important to use a resin that cures
fast and does not have to bubble and de-gas. Then they probably finish
it off with a coat of clear, self-leveling protective lacquer. And
some sanding. I'd have to smell it or taste it to really know.
Another issue with ZCorp is that the old machines (the 310, 450,
and 510) all have problems printing pure black and pure white colors.
They turn out grey-ish and yellow-ish respectively. The new 650 machine probably uses a dedicated
white and black ink cartridge to solve this problem (like a sub-dye printer). Also, while ZCorp markets the machines as clean, office-friendly products. In reality, prolonged use causes a layer of white flour dust to cover every piece of furniture in your room.
So there you have it. ZCorp. The Good, The Bad, and The Ugly.Really, I like ZCorp. I like playing with it. But it's going to be killed by Objet full color printing in 5 years. More about that story soon =D.
