Lecture Notes
I’ve updated Week14’s lecture notes in my gitbook .
Assignment
design and make a 3D mold (~ft2), and produce a fiber composite part in it
Design
About this week’s assignment, I got inspired from my lego container.
I can make a lid for my box, why not?
I design the model in Fusion 360
You can download the stl and dxf file here.
CNC
The CNC machine in SZoil still out of work. So we went to Fablab XH for help.
The machins in Fablab XH is a CNC Router VR1212B. And I use a 6mm endmill for milling.
Change the endmill:
I use HDF as Set the parameters and it’s ready to mill
Speeds and Feeds:
- Chip load: ~ 0.001-0.010” = feed rate (inches per minute) / (RPM x number of flutes)
- Cut depth: ~ tool diameter
- Step-over: ~ tool diameter/2
Here’s my mold for composite:
Composite
We use epoxy resin and vacuum bagging for composite process. I’d like to use two different kinds linen layers.
Fisrt step, I use plastic wrap as my release agent.
And I cut the fiber into small pieces so that them can form finer shape.
We buy new epoxy resin under the advice of Professor Hu.
Mix them together with proportion 1:1 and stir well:
Place the linen with resin layer by layer:
After the layup was complete, place it into a vacuum bag which needs to be tightly sealed.
Remove the air:
The sealed bag has to wait overnight. The next day it’s harden and I peel it from the mold.
The edge is a little out of shape, although the front and back side looks ok.
Many thanks to Professor Hu and Jay for helping us a lot to do this assignment!
