Tuesday, July 11, 2017

Fume Coffin Instructable - Laser Cutter Exhaust Filter

So I designed and built this.

It's called the Fume Coffin, and it's a laser cutter exhaust ventilation filter for my 50W CO2 laser cutter.

Design documentation, build instructions and analysis are all here:

Sunday, March 12, 2017

Microwave-bent Plywood

I'm interested in bent plywood techniques.

ZenziWerken uses an intriguing technique to craft this bowl. 6mm birch plywood is cut (a CNC router was used here). Then the cut-out was rinsed with water and microwaved at 600W for 1 minute. The bowl is then shaped in a form (another bowl in this case) with lead weights and clamps. The bowl was allowed to dry and harden. Finally, some wood glue was applied at the tops of the spiral arms.


The project files

Friday, March 10, 2017

Box Generators

I have built a handful of laser-cut projects based on boxes generated by www.makercase.com. Starting with generic box designs generated to my size specifications by the webapp, I modify and customize the box designs in Illustrator to create matching nesting boxes, lids, additional supports, ornamentation and other variations. 

Box generators are an effective way to make easily laserable box designs with pre-layed-out joints. (I find finger joints work well for most of my designs.) There are many box generators. Many are webapps, some are Python scripts, some are plug- ins for Inkscape. This Instructables article provides an excellent survey: The Ultimate Guide to Laser-cut Box Generators.

The major problem I have been encountering with the box-generator-Illustrator scheme is that it puts too much design complexity downstream from the box generation for anything but the most trivial projects. The scheme relies heavily on your wits and planning to get everything to line up and fit. 

I've found the design process is almost-manageable, but too often I make minor errors that result in the design turning out just slightly wrong. Sometimes the error can be remedied by adding a support fixture or some hardware. But the more I'd increase the complexity of my projects, the more I'd run into limits from the box-generator-Illustrator scheme.  

An obvious solution would be to iterate -- address the design flaws -- regenerate the cut files and cut the design again. The ease and low cost of laser cutting would seem to encourage this approach. But it's wasteful, especially if the design is for a one-off project. It's a classic artist's dilema -- smash the clay and start over.

A better approach would be to catch these errors before I cut the designs. 

A storage box with a matching lid.
(Error: The lower box height was
the height I had intended for both
the box and the lid. Also, tabs on
lid could fit more tightly.)

Box and nesting lid with
matching slot for a cord.
(Error: inner box exactly fits inside
outer box making it very difficult
to open.  Needs a thumb tab to grab
and prevent full nesting.)

A rack to hold a bamboo tray.
(Error: the rack was intended to support
the tray exactly on an interior ledge,
but the rack ended up one material
thickness too small. So it didn't quite
 fit. Remedied with screws in
bottom of tray.)

Toilet paper holder 😁
Designed to fit exactly over
a built-in fixture on the wall.
(Errors: Missed exact depth of existing
fixture by 1/4 inch causing it to wobble.
Also, design is silly looking.)

What's next: So is CAD the solution?