November 2010
Redesign of Makerbot's MK5 Plastruder
Makerbot’s MK5 Plastruder is a significant improvement to the previous MK4. The new model is designed for reliablity, low maintenance, and ease of use. They have completely redesigned the heating element, barrel, and nozzle to make the extruder as long-lasting as possible. In comparison with the MK4, the components screw more tightly together, and the tool is smaller in general. The resistors in the heating element heat very evenly and provide a very consistent temperature. The new filament guide system and drive gear have been redesigned to produce a much greater push strength and a smoother slide than the MK4. The new tool can extrude smoothly for extended periods of time.
I have redesigned this tool so that it can be powered by a snap motor by JrKerr. In order to accomplish this, it was necessary to turn the entire assembly upside down so that the filament moves downward during printing. The filament now runs alongside the right side of the drive shaft instead of the left as in Makerbot’s version. All the acrylic plates have been modified, and the tool now includes top and back plates so that it fits on a standard Fab@Home tool mount. The Plastruder needs to be heated to 230 degrees, and it sits at just the right distance from the build base, which is heated to 100 degrees. Once calibrated correctly, the tool can be used in almost the same way as the MK4 was on the Fab@Home, and will produce ABS models with a high level of accuracy.
Thermoplastic Tool on the wiki page: http://fabathome.org/wiki/index.php/Fab%40Home:Tools#Thermoplastic_tool
Pictures, DXF files, and assembly instructions on Thingiverse: http://www.thingiverse.com/thing:4892
Full View of Plastruder
Side View to show tool mount
Plastic printed butterfly
svg2fab
It is my pleasure to introduce svg2fab: a lightweight alternative to FabStudio, useful for quickly producing working FAB files for primarily 2-dimensional Fab@Home toolheads. Two input files, an SVG and a toolscript (.xml), are specified either in a simple GUI prompt or as command-line arguments, and a FAB file is written to a default or specified output path.
svg2fab provides an advantage over FabStudio for efficiency in producing print instructions for tools like the new vinyl or foam cutters, which don't have a heavy reliance on height (i.e. multiple paths in the z-direction). Vectorized graphics (SVG) serve as a convenient medium to make these essentially 2-dimensional print jobs. Software options for SVG creation include Inkscape (free) and Adobe Illustrator (commercial), and these programs are much easier to use than 3D modeling software.
As of svg2fab v1.3, only straight lines are supported--curved lines are approximated as straight ones--and single-material outputs are produced. Check out the most current release at the Launchpad page!
High contrast text on acrylic
If you didn't know, here's a way to get snazzy high contrast text onto acrylic.
Theoretically the Epilog laser we use should be able to use color mapping to simultaneously etch raster and vector outlines - but I haven't been able to get that to work with the software at hand.
So, I export the cutting layout from SolidWorks as an Adobe Illustrator file. Then I open it in Inkscape, add some text where I want it, then delete the outlines and send it to the laser cutter as a raster file with a fairly high power setting to get deep surface etching. Leave the sheet in the cutter.
From SolidWorks, cut the parts themselves in vector mode. Remove the parts.
Now, run over the area with the text with a permanent marker for light colored acrylic. Don't worry about overflow - if you wipe over it with a paper towel immediately afterwards, you should get ink soaked into the text and a flawless surface elsewhere.
And there you have it:
Actually - even more awesome: white correction fluid on black acrylic:
