This blog post will be about using a CNC router tool to engrave my 3D model into a foam block for mold casting. This technique is an excellent way to create molds for various casting processes. CNC routers are computer-controlled cutting machines that can precisely cut and engrave various materials, including wood, metal, and foam blocks. In this post, I will discuss the process of using the CNC router to engrave a 3D model into a foam block, the process behind this technique, and the final result.
Pre Fabrication
Once I have imported my stl. file into the software for the CNC router, it will take the information encoded and create a g-code language for the computer to read, understand the design, and how to cut it. Below is what the CNC router machine looks like at the Abington Makers Space.
CNC Router Machine.
Inside the machine is not as complex as it seems. The metal bars allow the machine to move front and back as well as left to right. The pink tube is a vacuum hose that sucks up all of the foam once the drill begins cutting. The green pieces are placeholders for the block of foam. Before using the machine I had to make sure my file was correctly set and I scanned the file for errors. Once the file was ready it was time to set my foam block in the machine as well as set the CNC router arm in the center of the block to begin cutting.
CNC Router Arm is Prepared to Start.
Once the drill nose was set directly in the middle of my foam block I clicked the start button on the computer and the CNC router immediately got to work. The estimated time for my engraving to complete was 8 minutes.
Engraving Process on Foam Block.
Final Fabrication
Above you can see the CNC router engraving my model from Fusion 360. If you are interested in seeing the design process of my model click here. As time went on the cuts went deeper into the model. Once the model was finished engraving the CNC router finished off by giving the surface of the foam block a pencil cut which is a fine line design repeated on the surface of the foam block. Below is the finished product on the foam block.
Top view of Engraved Model.
Side View of Engraved Model.
Front View of Engraved Model.
In the third photo, you can vividly see the pencil finish lines the CNC router added. If you have followed my design process you may be able to tell that the router did not add the loft clover design. I am unsure why this design did not transfer. A couple of theories, one is when I scaled down the model to fit into the box the clover design was scaled back down to a circle. Or it got lost in the g-code.
Overall this fabrication was interesting to watch and I can see it being useful for artists who create mold castings for a living. I always enjoy getting my designs from Fusion into a tangible piece, this is one of those cool pieces I can feel and see in real life. I had fun using the CNC router tool, it was not as intimidating as it seems it was probably the second easiest tool I have used in the Abington Makers Space. I am glad I have learned this skill for potential future uses.