Table Of Content
I decided to go for an “off-the-shelf” model in order to save time for hands-on part of the assignment.
I took a 3D model of a
mask
from thingiverse. With Rhino I prepared the model for milling
I used
Cut3D
software to produce the files to control our
LinuxCNC
milling machine.
First load the stl files made with Rhino:
I defined a new tool with 4mm diameter. I set a pretti high feed rate since the machine will not encounter much resistance milling styrofoam
I also defined a finishing toolpath with same speed and tool of roughing phase.
Finally I exported the file for LinuxCNC using a special profile Linuxcnc_mm.pp that i downloaded from LinuxCNC website.
Linux CNC has a simple interface to move axis and start/stop a job
This is the control box LinuxCNC is connetcted to:
This is our milling machine:
I made the mold the wrong way since I milled the negative (as molding and casting) instead the positive
Milling in operation. Very very noisy
I used 10 layers of wax in order to avoid that the resin attaches to the styrophone
First I put a thin plastic layer in order to ease de-attaching
I made the resin mixing 40 g of Hardner and 80 of Epoxy
I made small pieces of fabric in order to position them better on the mold
I made about 5 layers
Then I followed these instructions:
Finally I put everything in a bag
Sealed it with mastic
Switch the vacuum pump on and let it work for 7 hours
The mold was broken since the bottom was very thin and it didn’t stand the force of the vacuum machine
Tha mask was not perfect but still I decided to finish it to see how it looks the final result
Let’s have a try!
composite_tutorial.pdf
Finishing Toolpath4mm45 - Top.ngc
Linuxcnc_mm.pp
Linux CNC website