CNC CLASS
This week we had a lecture on how to use the CNC machines. We got a chance to look at these big machines up close and see all the different buttons and components, along with the whole process of setting it up. Our assignment was to design something BIG something using this machine. We could use up to a maximun of half full board measuring 1200x1200mm of 15 mm thick pine plywood boards.
I didn't have too much time to come up with ideas for this project, since I have been busy preparing for Design Dialogues coming up in a few weeks and I've focused on trying to complete final design interventions. I thought back to a board game I would always play with my dad, called cribbage.
The game is a common card game I used to play with my family in Canada, whom I haven't seen since 2019. Cribbage, or crib, is usually played by two players, or two teams, and it involves playing and grouping cards in various combinations which gain points, and those points are then tracked on the board. The first person or team to arrive to the finish line wins.
The classic crib board designs are a flat wooden board approximately 250–300 mm long by 70–80 mm and 10–20 mm deep. Although I wouldn't consider it a "big object", it fit perfectly with the dimensions of the pine plywood boards given to us. What I did notice, however, was how small each peg hole was, so I need to speak to a Fablab member about whether it would be possible to use smaller attachments.
The structure of the cribbage board actually reminded me of one of the photos Edu showed us during class, of the old, perforated cnc machines cards. I believe it would not be too hard to make this piece, but the difficulty would definitely lie in the fact that the holes are so small (a bit bigger than toothpick size).
I did some research on existing documentation on creating the design, and found these useful webpages:
Instructables Rockler
I created the design in Fusion, following the guidelines and tutorials from the above websites, but modified the size and borders.
Then, I exported the design to seperate .dxf files, one for each layer of cuts.
However, there were no slots left to book the cnc this Tuesday :( So I will have to do it on Friday or next week.
In the meanwhile I worked on importing my file to Easel, so I first checked out the introductory video it showed me:
I realised that it was easy to write text and make simple drawings. So I imported my files, and changed up the settings.
In the end, Santi told me to import the project in Rhino and make precise modifications, because we were going to have to change the mill bits three times. So I got his help modifying the file a bit and exported the separate layers. Starting with the screw, we chose a 3mm bit and the same for the holes, then we switched to 1/16 inch end mill (1.58cm) for the engaving and finally a 6mm one for the outcut.
Then, it was time to use the CNC machine. I have to say this machine was the longest set up process out of all of them, and probably the most complex too. Josep helped me with everything, and by the third time we had to change end mills, I was cabale of doing it myself.
I would say that even though my project was small, the complexity lied in the precise cuts and engraving we had to make. I had to learn how to switch up then end mills well and reset the Z-0 point with the button continuously.
I also noticed that due to the layered nature of plywood, the top layer was chipping off in between each hole. I decided to embrace it, and chip the inner part off, revealing the darker layer below.
To take this project further and make it even more customised, I would like to engrave a small design, either using the laser or using a pyrograph to burn the wood myself.
