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WEEK 8: COMPUTER CONTROLLED CUTTING

Day 1

The CNC is basically a really big milling machine.

I think…

Day 6

I’m extremely behind on this project.

I’ve had so much trouble with my computer that my use of the design programs is still subpar. I’ve yet to finish my design for the CNC and since the whole point of the exercise is to build something big and I only have one shot at it, I’m weary about making something just for the sake of finishing within the week.

The true complicated part of this week isn’t even the design, but the planning of the strategy behind the actual use of the machine.

There are many things to be considered here. The speed of the tool, the point of pressure, where the wood will be drilled into the bed of the machine, etc, etc. I won’t be able to work all those things out until I have a finished design.

Day 25

I’ve been working on a design for a pliable wood chair, but I may have attempted to do something too ambitious. I tried to also make it a parametric design and this proved to be too much for my grasshopper skills, or lack thereof.

Still, I remain optimistic, we’ll see how it turns out.

Day 53

I’ve finally gotten around to the CNC.

Everything has changed design wise, as I’ll be attempting to do a pliable wood stool.

Since the wood available is 15mm thick, I’ll have to do some tests to see what pattern is the best for that level of thickness.

As far as I understand the thicker the wood the longer the stripes along the wood need to be, to better distribute tension and avoid breaking the wood.

The test design and strategy came out like this, to verify the possibilities.

When it came to doing working with RhinoCam to do the strategy for the milling, these were the settings I used. There are two types of profiling, that is to say, the one that mills on the outside of the design and the one that mills inside the design. Since our CNC doesn’t have a a vacuum bed, screws need to be used to fixate the wood to the bed of the CNC, to avoid it moving around during the milling process and those have to be milled too, to know where in the wood the screws should be put to keep it in place.

The screws themselves need to be placed in strategic places as to keep the wood in place throughout the whole milling process.

We found a scrap wood for the test and we got started.

When the first test was being milled, since it was a single line that was to be milled, when the wood started to separate and become pliable, it moved too much when it was being separated from the bed. Since it was a single line and all the material that was being cut out was material that couldn’t be cut out later, we didn’t put a screw to secure the inner design to the bed so it came loose and broke when the tool put too much pressure on it.

The other two designs were milled without a problem but there was some worry something similar would happen.

The last test design didn't bend at all, as expected.

The design that made the wood most pliable was the broken one test, so instead of trying to do that one again, given the dangers and the fact that the inner design can’t be screwed on because it would ruin the wood of the stool, I decided to simply use thinner wood.

MDF isn’t the best option for anything but it’s what we have available and I’m determined to do something with pliable wood.

I modified the design slightly, a meet between the two design that showed best results in the thicker wood.

We did another test with MDF scraps and the results were much better but something similar happened during the milling. During the final cut the wood was moving a little too much for comfort and so we modified the design and strategy as to make the same shapes but cut in a different order to avoid risks.

Now, it should cut the inner pockets before doing the final outer cut and it should remain stable throughout.

Day 55

The day has come.

Since I modified the drawing, but not the design, to help make the RhinoCAM strategy work, this time it should so all the inner pockets first and then do the silhouette of each shape as a single line, after all else is done.

The strategy was the following: