Similar to those pin-toys of yore, here is a sign made with nails. As with many things, the CNC makes this much easier to do than would be possible otherwise. It’s not the most practical use of nails, but it is a convenient way of storing them.
The PRL in this sign stands for the Product Realization Lab (mine, not Stanford’s).
Since I was in the neighborhood, I dropped by the Vancouver Tool Library to say hi. The concept is very similar to the West Seattle Tool Library, with the exception that there is no workshop next door. The shopkeeper mentioned that they are looking to upgrade to a larger space - would cohabitation with VCL be a possibility?
Science Day in India, posting whole series of Scientists, their inventions or discoveries.
#352 Orbital – This is so simple, just a bunch of circles, moved and masked. Still it is so interesting. – A new minimal geometric composition each day
The Triforce: a study of wood shop equipment and gilding. Eventually, I want to make one that’s metal and gold-plated. If I can find some tungsten and a way to work with it, it would have the same density as one made of solid gold.
Sketchchair #7 Part 2
After laser cutting a one-quarter-scale sketchchair in 15 minutes, I thought that making a full size sketchchair would only take four times as long (an hour).
Nope. This one took the better half of a day. But, I did learn a lot of lessons (recounted below), and the next one should be done much faster.
I started with a 4’ by 8’ sheet of 1/2 inch veneered plywood from Home Depot. A couple hours on the full size ShopBot later, I ended up with some ribs.
At this point, I could sit on it and it wouldn’t collapse.
A profile view.
The completed chair, with no glue required!
Lessons:
- Use non-veneered plywood
Veneered ply is not kind to beginners. The upcut drill bit I used blew out the surface veneer, requiring hours of postprocessing, not to mention the splintering. I should have used a downcut bit to make an initial pass of the pattern, then switched to an upcut bit to complete it. This is a good rule to follow even for non-veneered ply. - The vacuum table is not a magic bullet for work holding
My program cut each piece completely before moving on to the next. As each piece was cut out, it decreased the vacuum’s effectiveness. Part way through the job, the upcut drill bit started lifting the plywood up in a bad way. I stopped the machine and clamped down the board, but the interior non-clamped regions still chattered slightly. I didn’t realize it at the time, but the chattering was also pulling out the drill bit until the Z level was a half inch away from its original zero position. This resulted in more stress on the bit and a huge channel cut into the vacuum board. Next time, between the downcut and upcut pass, I need to plan out my workholding. - Measure your material thickness
The tolerance on my joints was extremely tight, meaning that my material was slightly thicker than I thought it was. I started by forcing pieces together with a mallet, but had to use a file and vise clamps to get most the pieces to actually fit. At some joints, the veneer would buckle making things worse. Scaling up the pattern size just a bit would have made the tolerances much more forgiving.
So much nostalgia. I still need to make a wooden master sword and shield using the ShopBot.
