For cost of production (both materials and manpower), the fewer materials or colors, the better. However, including even a single extra color creates a strong impression of luxury; it’s no longer “just a box.” Nothing could illustrate this better than Pimoroni’s Pibow case for Raspberry Pi. All those unique layers add up to a lot of production work, but people see this and really want it:
For our own Internet of Things Printer, we could have just slapped a plain black front on it and called it done…but the “torn receipt” visual pun makes it distinctive. Even when turned off, it implies the kit’s purpose.
Engraving similarly adds a touch of class, but it’s time-consuming. When oursourcing laser production work, your cost may be based on total laser time, regardless whether engraving or cutting. You’ll need to decide if the engraving is worth it. A “kiss cut” (vector scoring the surface of the material, creating just an outline) might be an acceptable compromise for many situations, though it lacks that certain product-ness of full-on engraving.
Kiss cut (left) vs. engraving (right)
Timesaver: When engraving kit parts, try to tile the designs to engrave short, wide areas. Turning everything 90 degrees may make a huge difference in lasering time.
When engraving, the laser head “raster scans” in contiguous lines. The horizontal extents of each engraved line must be fully traversed, even if the middle is mostly un-etched. The tiling on the right has about a third less “dead space” and will etch more quickly.
If a case design has two seemingly identical parts (e.g. left and right sides), don’t cut two identical copies. Instead, mirror one of the parts. The laser beam isn’t perfectly straight — it’s focused and has a slight hourglass profile — and this manifests in the cut parts as a slightly beveled edge. Mirroring “identical” parts ensures these bevels are compensated for on both ends of the box…otherwise you get a skewed parallelogram.
Internal braces and/or a front-to-back, top-to-bottom tab & slot design can help conceal assembly hardware where it’s less likely to be seen. Some products (like the original MakerBots or our Ice Tube clock) just look cool with the hardware all visible — makers like to see the things they’ve built. But other times we want something more finished and appliance-like. Unfortunately we can’t hide all the hardware — that’s a limitation of laser cutting vs. molded enclosures — but with careful design we can minimize the distractions. Tabs and slots are almost unnoticed. Screw heads are a minor distraction. Nuts and T-slots are much more unsightly, so try to hide them at the back or on the bottom.
These light cubes — inspired by paper lanterns — use an internal brace (a hidden third plane between the front and back pieces) to conceal their T-slot construction. Tabs and screw heads are visible from the outside, but these are much less visually disruptive than hex nuts or T-slots.
The Internet of Things Printer uses a similar internal brace to keep the top and front faces smooth and free of industrial protuberances.
Screw heads are visible only on the sides. T-slots on the back. Nuts on the bottom.
Screw heads are visible only on the sides. T-slots on the back. Nuts on the bottom.
If you can’t hide it…make it obvious! Laser-cut enclosures can’t help but exhibit that telltale, overlapping-planes appearance, and it can be a challenge to downplay this look. Amanda “w0z” Wozniak’s design for the Monochron clock kit instead exploits the plane edges as a design element rather than a liability…there’s a hint of Art Deco style or Mission furniture implied in this case design.
In some situations you may want to arrange your vector files to cut enclosed shapes first (e.g. cut slots and ports before the perimeter of a piece). Depending on the design of the laser bed, a part may drop down from the material sheet as it’s cut. When this happens, it’s rarely a straight drop — the part is now slightly shifted, and any interior cuts will be misaligned. You can usually specify cutting order using different line weights or colors. Not all laser designs suffer this problem though, and the driver software may already take care of cutting enclosed shapes first — a major timesaver!
Page last edited March 25, 2013
Text editor powered by tinymce.