A7 - Computer-Controlled Machining
Brief
- Make (design + mill + assemble) something big
https://fabacademy.org/2024/labs/lakemac/week7-group/
Making our own job for a CNC like this was great, it really inspired a couple of ideas for projects where size is a constraint. The workflow for setting up and operating the CNC was pretty straight forward and easy in my opinion. I'd be keen to see what some of the other CNC interfaces and workflows are though.
My Table
I wanted a nice place to be able to store and demonstrate my project. A table would be sick! Taking inspiration from my press fit kit, I wanted to design a table that didnt need tools to assemble.
The table would be long, to fit the box that I carry all of the parts around in and allow for a nice size diorama to fit on top.
Design
Our mill, the https://www.makerstore.com.au/product-category/cnc-machining/cnc-router/cnc-workbee/ required the gcode to be generated through Fusion360, so were locked into that for designing. I started with the table top, a nice long section with some rounded corners.
We also had to consider the size of the mill bit, these circles were added as a variable so that it could be changed parametrically.
First the legs, I wanted these to be similar, one piece for longways and another locking piece to give stability and some extra surface area on the base.
LEG
Now the top surface, this should be able to fit the box of parts I ferry to and from work. (and big enough to fill a sheet of the ply we are using).
Top
And add the slots for the legs, these should be bordering an interference fit. I intend to use another bit of wood to drive these in. The humidity will also affect how these come together.
Finally, assemble all of the parts together (in CAD)!
Generating Gcode
Once the design was completed we had to import the bodies into the manufacturing workspace. Lay them all flat and ensure they fit on the material we are using. Beforehand our lab supervisor and teacher, Claire said that we would be using 1200mm x xxx mm x 12mm plywood.
I added the stock size, and arranged all of the peices into the material.
Then we had to hop on the FabLabs PC with all of the tool libraries and export settings.
We selected the type of cut to do, in this case we are making an outline, with a full depth cut - so a contour would be used. Select the tool, speeds and feeds that we characterised.
And finally a finishing pass to clean any loose bits and bring in the edges to the final dimension.
Running the job
Cleaning up and assembly
Once off the mill there were some shards where the bit didnt fully cut to depth. This was quite easy to take off with some sandpaper or a hard object (I used the back of a box cutter).
Sanded off the sharp corners on the top and started assembling each of them.
Its at this point I realised that adding a 3mm taper would help so so much. Regardless, with some sanding and elbow grease, the legs were on.
COMPLETED TABLE
Resources - DESCRIPTION
FILES
DOWNLOAD LINKS HERE