I wanted to create some piece of 3D artwork. Since I had some experience with wood already, I decided to move forward with it again, but choose plywood this time. I wanted to create something which would not need any explanation. Something what’s going on now, and affects everyone. Now it’s COVID-19
After initial sketch and I made a prototypes, 2D and 3D
Next I needed a sphere. I bought one on Etsy, which needed assembly. Put it together and painted. After sphere was done I started experimenting with numbers. I needed sphere first, because numbers size depended on sphere diameter.
To cut numbers I used laser engraver/cutter and 3mm plywood. I tried small CNC machine first, but it didn’t work as I expected and took too much time to cut plywood. Laser does it faster and cut is much cleaner.
But, where was a problem. Big plywood sheets are more uneven, and because of that cut may be distorted. Also, bigger sheets are more expensive. I decided to make some sort of puzzles, or locks. But I needed to figure out which pattern will work better.
To achieve a cleaner cut I added an air assist system to my laser. There is no stock air assist for this model, so I had to make it. This is a really useful add-on to any laser. Simply saying it adds about 15-20% more power while reducing burning. Also, I found out that putting a masking tape on plywood prevents cut edges from burning.
Next, I needed to find a locking pattern which would work for big numbers. Smaller parts make an assembled piece more flimsy, but they are easier to cut. Bigger parts more sturdy. But it’s not easy to cut big parts as I explained before. I was experimenting with different locking patterns, wasted a lot of plywood…
Also, I was making a big mistake with first cuts. I rotated parts in Lightburn trying to fit as much as a can on a single sheet of plywood. This turned out to be a total waste of time and plywood. The reason is that the laser beam is not perfectly squared. For example this one is 0.06×0.08mm, so the same file can be cut differently if you rotate it. As a result, you will get a gaps between pieces.
Now I need to figure out how to connect the whole piece to a sphere. Actually I needed to connect only 2 center numbers. The big “2” and small “1”. The best way was to remove couple links from the sphere and make these numbers part of the sphere
Figured out with the pattern finally and started cutting. Also, decided to add “19”.
Sanding, painting, cutting out connectors
Overall, I like it. For the first try I think it’s not bad. Even though it took way longer than I expected, I learned some useful laser cut tricks (I had never used laser before).
And I have a lot of plywood left, so I’m definitely going to continue with laser cut.