A FlatPack RepStrap or FlatPack RepRap is analogous to flat pack furniture. Some characteristics common to all three are:
- Most of the parts are effectively 2D shapes cut out of flat materials. (Rather than arbitrary-cross section Extruded Aluminum or the thick, complicated 3D shapes that can be produced by a rapid prototype printer).
- Since most parts are flat, they are easy to stack and pack into a relatively small box, making it easier to store and deliver.
- It requires only simple tools to assemble.
A FlatPack RepStrap -- such as PonokoRepRap or LeCorb or RapMan or CupCake or CupCakeStrap or Isaac -- is designed to make the same thick, complicated 3D shapes that the RepRaps can make -- for example, all the reprapped parts needed to build a Mendel. However, a FlatPack RepStrap is unable to make parts identical to the parts that went into it. Since cutting such 2D shapes is relatively easy with *other* simple tools, however, this is no great loss -- and it makes FlatPack RepStrap a useful RepStrap pathway to start from simple tools and end up with capability of producing thick, complicated 3D shapes that can only be produced by a rapid prototype printer.
It appears that it takes fewer parts and is therefore faster to assemble an adequately stiff outer frame out of a few large flat sheets than out of a bunch of studding (allthread) and nuts and angle braces.
A FlatPack RepRap -- such as most LaserCut RepStraps (Builders/LaserCut RepStraps) designs -- is a machine that designed to both be assembled out of such parts, and then cut flat materials into parts identical to the parts that went into it. (A FlatPack RepRap does not necessarily have the ability to make thick, complicated 3D shapes like other rapid prototype printers, but that seems like a useful ability to have, and it apparently only requires swapping out the head).
A CNC Router is one machine that can cut such shapes out of flat materials.
A water jet cutter is another kind of machine that cut such shapes out of flat materials.
Structural frame materials suitable for building FlatPack designs include
- plywood: many PlywoodRepRaps
- MDF (medium-density fibreboard): SGBot, OverlapStrap, WedgeStrap , RepStrap Bertha ... also used as the build platform in many, many RepStraps and RepRaps.
- acrylic: Huxley Seedling, BitsFromBytesRepRap, Delta, ...
- polycarbonate: Kiwi-M5 Mendel Battle Tank
- Is it possible to build a RepStrap mostly out of "Laminated Laser-cut Cardboard"?
- ... other materials ...
... Is it possible to take a FlatPack RepStrap design intended for one material -- say, acrylic -- and built it out of some other material -- say, MDF ? ...
... what other kinds of tools can cut such shapes out of flat materials? ...
... MegaRap is designed to cut a full-sized sheet of plywood ...
water jet cutting vs laser cutting
Benifit of Laser cutting over waterjet cutting
The tolerance of the cut is better with Laser cutting as the size of the water jet can change for combinations of these reasons.
The size of the garnet/cutting medium can vary.
The wear on the diamond or spaphire cutting head changes as its used.
Wear on the focusing tube.
All of the above change the size of the kerf the kerf is the size of the jet typicaly 1.6mm.
The Kerf is cone shaped so cut edges have a slight taper from the top of the cut to the botom.
Another disavantage is the cut edge finish feels is a bit like fine sandpaper.
With water jet cutting parts need to have a border around them thus the cut length is longer this could explain the 20-30% diffrence in price.
(ie Water Jet cutting seems to be 20-30% more expensive than Laser cutting).
Also parts <60mm diameter need to have a tab to stop them being blown away with the waste. A tab is bit like sprue on an airfix model holding the parts together.
MDF and Plywood can be cut with just water this avoids most of the problems except for the need for Tabs.(water without abrasive added)
The Kerf with water only is typicaly 0.5 to 0.8mm
Advantage of water jet cutting MDF and Plywood there are no burn marks.
Yes MDF and PLYwood can be water jet cut They do not come out wet. In the pic you can see the Tabs and the kerf hole in 5 o'clock position of all the cutouts.
- If you don't have access to a laser cutter, PrintItStickItCutit describes an alternative way to cut out all the pieces of a FlatPack design using low-cost tools.
- Flat-packed robots:
- "Teach Kids to Code with popupCAD and Flat-packed Robots" mentions "this origami style of robot design"
- "Origami Robot Folds Itself Up, Does Cool Stuff, Dissolves Into Nothing"
- "Origami robots: the future of the flat-pack?"
- "The Deep Design Thinking Behind MIT’s Incredible Origami Robot".