For the 3d printing project, I hope to make a “rocking chair for two” or adult version of that fun toy we had as kids. My mockups will improve.
I propose to do a project combining my data representation class with my digital fabrication class for the next assignments.
I would like to take the data set available on The Guardian’s Data Store, “UK and US temperature changes for the last century” and evaluate it for the assignment— first as simply as possible, and then in a way specific to the “unique character of the data.”
I hope to create a few different lasercut & preserved options that would communicate the temperature data, cut or etched on leaves and then mounted as jewelry— necklace, earrings etc.
The link between leaves and temperature changes is literal according to this PBS article, “Why Do Leaves Change Color,”
Studies from Europe and Japan, where color change and leaf fall is extensively monitored, indicate that trees are flowering and leafing out earlier in the spring and holding their leaves later in autumn, said Richard Primack, professor of conservation biology and plant ecology at Boston University. These changes are linked to warmer temperatures.
Blackberry mockup on VectorWorks. Everything is drawn exactly to measurements of the device itself.
Now, if we’re ever creating something with keys instead of touchscreens…
This video shows a hot wire foam cutter machine carving the number 3 from a computer file.
1. Method:
As you may be able to tell from the video, the “hot wire” is literally a thin, taut metal wire that is heated and then passed through the foam.
The wire is mounted above a cutting table— either horizontally or vertically. Vertical wire is used to cut small, complex shapes. Horizontal wire is often used for construction and packaging.
- The wire runs up and down tracks on either side of the table
- The hot foam cutter can also be guided by templates
- There are CNC hot-wire foam cutters that also offer lathe attachments to make spirals or forms for architecture plans.
2. Materials:
2.1 Wire: Leader wire that is used for fishing lures is a good option or for the DIY methods, an electric guitar string.
http://www.sears.com/shc/s/p_10153_12605_SPM4965755901P?sid=IDx20101019x00001a&ci_src=14110944&ci_sku=SPM4965755901
2.2 DIY: You can make your own hot-wire foam cutting CNC relatively cheaply and there are good support forums around this topic.
http://rcrodeo.com/how-to-cut-foam-use-a-hot-wire-foam-cutter.html
http://www.instructables.com/id/Hot-wire-foam-cutter/
There are also miniature crafters’ sculpting tool kits for smaller scale projects:
http://hotwirefoamfactory.com/-K02-Sculpting-Tool-Clamshell.html
2.3: What they mean by foam:
You can use “thermofusible expanded foams” that melt at a low temperature.
Here are the names of these foams, in case you come across them. Foams vary in degree of density (weight of 1 cubic foot of the material). Higher density foams are harder, more rigid and weigh more.
This page has more detail on different types of foams:
http://www.flyingfoam.com/FoamTypes.html
- Expanded polystyrene
- Extruded polystyrene
- Polymethacrylimide low density rigid foam (expensive)
- Flexible expanded polypropylene foams
- Polyethylene foams
More on which foam to use:
- People don’t recommend blue foam (sheets of it aren’t flat, etc. etc.)
- Expanded Polypropylene foam is forgiving in that it will spring back to its original shape
- EPP is used in the modeling world for combat gliders that need a high degree of durability. Since EPP is not a rigid foam, most all EPP gliders use fiberglass, carbon fiber, or spruce spars for stiffness. Because of it’s lack of rigidity and higher cost, EPP foam is not generally used in models that are covered with balsa, plywood, or obechi sheeting.
- Surfboard Foam / Spyderfoam: Surfboards are made from: Polyurethane or polystyrene foam
- On the other hand, pink foam, white foam and blue foam are all light but are more brittle and thus easily broken.
PSI Rating Density Cost Material
————— ———- —— —————————————
10.0 @ 10% 1.0# Low- EPS (Expanded Polystyrene)
15.0 @ 10% 1.5# Low EPS (Expanded Polystyrene)
25.0 @ 10% 2.0# Med EPS (Expanded Polystyrene)
11.0 @ 25% 1.3# Med EPP (Expanded Polypropylene)
23.5 @ 25% 1.9# High EPP (Expanded Polypropylene)
25.0 @ 10% 1.8# Med Owens Foamular (Pink Extruded Polystyrene)
25.0 @ 10% 1.8# Med Dow Styrofoam (Blue Extruded Polystyrene)
40.0 @ 10% 2.3# High Dow Hi-Load 40 (Blue Extruded Polystyrene)
60.0+ @ 10% 2.2# High+ Spyderfoam (Blue Surfboard Polystyrene)
3. Considerations:
- The wire must be tensioned— thus ought not be too long or needs to be tensioned by the placement of the ends of the wire (above or below the workpiece).
- Sometimes manufacturing engineers can only use files in the .dxf, .dwg, .tcw format— AutoCAD produced for the first two and TurboCAD for the third.
- Make sure to cut foam in a well-ventilated area
- Foams usually need to be covered to give more strength and to keep the foam clean. - People cover the foam with:
- Heat shrink plastics, and shipping tape; balsa, plywood,and obechi wood sheeting; and various composites such as fiberglass, carbon fiber and Kevlar cloth and resin combinations.
4. Uses:
- Signage, architecture modeling, prototyping, surfboard construction, recreational hovercraft construction, aircraft design
- Not just for modeling…
Dragon Eye is a fully autonomous, hand- or bungee-launched mini-UAV designed to provide tactical reconnaissance and surveillance information to field commanders.
