PROJECTS Print-in-Place Mechanisms
92 makezine.com
One-Shot
Wonders
Design moving parts
that print in place —
no assembly required
Written by Caleb Kraft
MATERIALS
» 3D printer filament of your choice
TOOLS
» Computer with CAD software and slicer software
» 3D printer
CALEB KRAFT is senior editor
of Make: and has been 3D printing
since 2013.
Something I find magical about 3D printing is
that you can design gadgets that have some kind
of mechanical motion — hinges, gears, pivots
that rotate or spin — that print all at once and
simply pop off the print bed ready to be used, no
assembly required. These are often referred to as
print-in-place mechanisms.
There are many ways to pull this off, but the
easiest one has to be the vertical hinge or pivot
point. Let me show you how this works, and how
best to create one of your own.
Think about how a simple hinge works,
standing vertically. You have a center pin and
an outer sleeve. To print a hinge, you connect
one side of your design to the outer sleeve and
connect the other side to the inner pin. In Figure
A
you can see what I mean.
If you printed this design with a gap between
the two parts of about 0.5mm, most printers
would successfully create two parts that do not
impede each other. If your printer is very precise,
you can reduce this gap even smaller. (To figure
out the precision of your printer for print-in-place,
try printing the “tolerance coin” to the right.)
There are some issues with the basic design
though. For example, if you were to print the basic
hinge shown at left, it would simply fall apart
as you removed it from the 3D printer. There’s
nothing holding the two pieces together.
The simple solution to this is to widen the
ends (Figure
B
), or in some cases, the center
section (Figure
C
). This creates a captive piece
that cannot be pulled apart. Simply adding a
45-degree chamfer at the bottom and top will
usually do the job.
A
CB
M83_092-93_CADtips_F1.indd 92M83_092-93_CADtips_F1.indd 92 10/11/22 9:47 AM10/11/22 9:47 AM
..................Content has been hidden....................
You can't read the all page of ebook, please click here login for view all page.