Computer Controlled Machining
This week is about computer controlled machining, and making something big!
Chair
I decided to try to make a small version (something that would fit on 4x8ft of plywood) of this chair.
Chair design |
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I designed the chair so that it could be cut in a 2D plane using only two tools (1/2" and 3/8"). We set up the job to leave an onion skin after the first cut to be sure that the large bendy pieces would stay flat on the vacuum table. |
.....unfortunately, as I learned, plywood is pretty crappy quality, and the poor glue between layers (and in some places complete lack of a middle layer), caused the back of the chair to vibrate out of place. |
So, next I tried recutting just the back piece in 3/4" veneer which gave a beautiful result and still came out very flexible.
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I had a friend help me put together the chair, the wood is a nice material to work with, we were able to flex/bend/stretch/compress it quite a bit without cracks. ...Now it looked nice, but with any weight on it the plywood started bending heavily, so I added cross-strings to keep in place, which helped tremendously. |
I still need to replace the zip-ties with a nice leather string for holding the surface down, and I would like to redo the sides in 1/2" veneer instead. Finally, though comfy, the center of mass of the rocking chair is currently too far forward to make it really comfortable, so I might fix that too: good news is that the surface can be reused! |
Chair Update: A ouple of days later, my unfortunate labmate sat in the chair and broke the sides. The cheap plywood definitely didn't do it's job. So three weeks later I finally had time to buy nice 1/2" birch plywood and redo the sides of the chair. (And while I was at it, I made an ottoman, and a table too). Super happy with the new design!! :) |
Here's the final files I cut: Chair surface came from this file. (I recommend lowering the feed rate quite a bit to avoid splinters). Chair, foot rest and table here. ...Also, I removed the zip-ties and added nice leather coord instead: |