Category: Digital Fabrication

Digital Fabrication Success

I’ve been working on a Digital Fabrication Technique for building precise 3D-faceted forms. I ended up making an armature, which is close to a good solution, but still has too much play in the joints.

IMG_0920One of the other resident artists at Autodesk, suggested a solution where I make wooden squares to solidify the joints in the armature. I cut out a variety of squares, each with a slightly different width+height, to account for the kerf of the laser-cutter. I also laser-etched them with their measurements.IMG_0917You can see here where I cut out a groove in the bottom of the armature, 1/8″ deep. The square fits nicely in there. I found that 25/1000″ seems to be the right amount of compensation.

IMG_0921I also added squares for the top joints.
IMG_0923Using the brad nailer, I adhered the bottom squares to the armature.

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Then the top squares and then the bottom panel of the structure.IMG_0925I built up the structure quickly. The precision of the armature made it easy to align the wood-paneled faces.

IMG_0927This is what it looks like before I put the last panel on.

IMG_0928And done! No glue or anything. Easy assembly.

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It looks just like the model!

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Digital Fabrication — Better

After the “Digital Fabrication Fail” based on my self-defined Fabrication Challenge, I’ve gotten closer to a more precise solution. After an evening of frustration, while riding my bike home, I realized that an armature for the 3D sculptures would be the solution.

This is a bit tedious design-wise since I’d have to custom-design the armature for every 3D form. However, it would work — I remembered the Gift Horse Project and the armature that we built for this.

armature_assembledI designed a quick-and-dirty armature in Sketchup (I know, I know…) and exported the faces to Illustrator with an SVG exporter.sketchupI then laser-cut the armature pieces and put them together.

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I made a few mistakes at first, but after a few tries got these three pieces to easily fit together.

IMG_0920However, even with accounting for the kerf, there is still a lot of play in the structure. You can’t see it in the images, but I can easily wiggle the pieces back and forth.

If I model the tolerances too tightly, then I can’t slide the inner portions of the armature together.
IMG_0919It is certainly an improvement, but I’m looking for something that has more precision and is still easy to assemble.

 

 

Digital Fabrication Fail #1

I’m working on some simple tests or my Faceted Forms Fabrication Challenge . I started with this model, which has 10 faces and is relatively simple.

digital_fail_solidThen, I laser-cut these pieces from a 1/8″ sheet of wood.

IMG_0904And, I also cut out these joints.

IMG_0905Then, using the brad nail gun and glue, I began with the base and built up the structure using the joints for support.IMG_0909The first level, with the rectangular base went well.IMG_0910However, when I started assembling the trapezoid sections, I quickly ran into problems. The nail gun pushed the joint blocks away from the wood, and it was difficult to align the joint pieces correctly. I had to redo sections over again. Although this photo doesn’t entirely capture the first-try-failure, you can see the nail holes everywhere and also the gap between the joints. I threw in the towel pretty quickly and went home to sleep on the project, and hopefully, will come up with a better solution.IMG_0913

 

Laserkerf and Mathophilia

Every cutting tool has a kerf — the amount of material that the tool itself removes in the cutting process. With a table saw, it tends to be large, like 1/8″. The laser-cutter has a small — but significant kerf.

I cut a 1/4″ notch and then used the calipers to determine that I have a 2/100″ kerf when cutting 3/8″ material at 8/100/500 (speed/power/frequency).

I then cut a 1/4″ groove and several notched cutouts, increasing the amount of material by incremental values. At 4/100″, (double the .02 measurement), the fit is perfect. 3/100″ is a little loose and 5/100″ won’t fit.

I’m glad I was a high-school mathlete.

kerf