7. Computer-Controlled Machining¶
Group assignment¶
1. Safety¶
Our big router table is a RivaCnc 2400. It has a workbed of 2400x1200 mm with vacuum table. The frequency controlled spindle has a max rpm of 24000 This is a big and powerful machine. Before using the machine you need an instruction session and read the manual first.
We don’t have any laser curtain or fence around it, so always be extra careful. Needed personal protection are:
- safety shoes
- safety glaces
- ear caps for the noise.
- Never have any loose clothing or hair when operating machines with fast moving parts!!!
2. Controlling the milling machine.¶
The RivaCNC is controlled by USB-CNC control software on the dedicated pc. This software expects ISO G-code. ![screenshot] To create the toolpaths and g-code we use VCarve pro software. This is a very nice software that imports pdf, ai, svg or dxf. It can also import 3D formats of images. You can do a lot of adjusting and design inside this software as well. Inside the VCarve we also keep a tool database, you can select a tool while creating a toolpath.
For this excerise we will mostly use 2D-profile toolpaths. You can select the lines in the drawing and adjust the toolpath parameters.
3. Design and make something big¶
As I wanted to focus on getting my programmer to work, as well as keep the lab running in Ghent, I haven’t gotten a lot further than a basic drawing on paper.
I want to make a little cupboard for the hallway where we can put in our shoes and some of Mysa’s things.
I already started drawing the design in Shapr3D on my ipad as well, but it still needs finishing. By the end of this week I want to make a 3D prototype using the laser cutter.
The milling will have to wait as I cannot travel to the lab this week due to illness.
Because we also need a cupboard to support our final project, I already drew the first design of the machine cupboard as well. It’s only a first draft, but working from home in my small makerspace made me realise that you need to be able to put away a lot of stuff and materials. I want to make a cupboard that folds open when needed, but is compact when you can work with less space.
As we want to make a travelling machine, the whole design cannot be too big and preferably we need to be able to transport it with a cargo bike.
With all the drawings at hand, it became clear that my body needs rest and proper care. Sitting still isn’t good (even though I walk a lot with Mysa), so I changed the design for the CNC milling once again. With the back problems, it was clear I needed a desk to do my work standing instead of sitting down.
I drew the drawing in shapr3D on my macbook. What a great software this is!
And to make sure everything would fit, I made a 3D model as well.
With the DXF-file at hand, it’s time to start milling.
Translating the DXF to toolpaths using VCarve. Everything will be milled in a 12mm poplar plywood using a 6mm end mill. First setting the thickness of the material and the starting position.
Selecting and calculating all inner toolpaths.
Afterwards selecting the outer toolpaths.
Having the toolpaths ready and saved, it’s time to move to the machine. I looked for a leftover piece of plywood that was big enough and placed it in the machine. I locked the plywood in place by using the clamps on all sides. Make sure to look carefully at your drawing to make sure they aren’t blocking the machine!
While Mysa was enjoying the sun, it was time to start milling.
Importing the drawing in the software of the machine and after homing the XYZ, it was time to press start. The software calculated it would take 39 min of cutting. In the end it only took about 25 minutes of cutting.
After vacuuming and sawing through the tabs, a first test revealed the stand to be perfect! Time to take out the sandpaper and start sanding. Thankfully the weather was beautiful and it could be done outside.
After sanding, I put in on the table in the lab and started working. It’s brilliant and saved me from an extra evening of back pain.
At home it also proved to be the ideal solution to watch a series with Mysa on the couch. Two in one. I love it!
Make your own laptop stand:
You need 12mm plywood or mdf. (I prefer the first.)
Enjoy!