8. Large format CNC (computer controlled Machining)¶
This week, I was assigned to the CNC group, where we focused on designing and cutting our projects. Each student received a sheet of MDF wood measuring 1220 mm by 2440 mm with a thickness of 12 mm. The requirements were as follows:
- The design must fit within the dimensions of the provided sheet (1220 mm x 2440 mm x 12 mm).
- The design should be “press fit,” meaning it can be assembled without using any external materials like screws, bolts, or glue.
- Given the 12 mm thickness of the sheet, ensure that the slot thickness is also 12 mm to achieve a snug fit.
Individual Design¶
First I did the measurements I want for the bookshelf and decided on the following:
shelfs & top: 700 x 300 sides: 1100 x 300 top: 300 x 700 back: 1100 x 700
Given that I was using the whole sheet, I had to use an offset of 30cm
Then I made the design using fusion 360 accordingly, putting a rectangle that has the dimensions of the provided to make sure that my design fits, creating female and male joints for each of them.
Design Steps:¶
- Created the Bookshelf Components: Each part of the bookshelf was modeled individually, ensuring accurate dimensions and proportions
- Extruded the Parts: The 2D sketches were extruded into 3D shapes to form the structural components of the bookshelf
- Assembled Using Combine and Align Tools: The parts were assembled by using the Combine and Align tools to ensure a precise fit and accurate positioning
- Repositioned Components for Separate Views: Since the construction of the bookshelf was confirmed, the parts were separated and rearranged using the Align and Rotate features
- Separate project files were generated for each part
Cutting the parts using CNC machine¶
Prepare the Machine¶
- Begin by removing the old piece of wood from the machine.
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Clean any wood dust that remains from the previous cut. Set Up the New Sheet:
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Place the new sheet of wood on the machine and fasten it securely with bolts at the edges.
- Ensure that the sheet is positioned at least 2 inches from the edge.
Load and Edit the Design:¶
- After exporting your design files as DXF, open them on the computer connected to the CNC machine using VCarve software.
- Putting dimensions of the sheet given to us.
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add a 30 mm offset from the edges to account for the placement of the bolts.
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Add a dog-bone fillet to the design.
The fillet radius depends on the drill bit size. For instance, if using a 3 mm drill bit, the radius should be half the bit size, 1.5 mm. Adding a small allowance, you might opt for 1.6 mm. For a 6 mm drill bit, I used a 3.1 mm radius. Create the Toolpath:
Select all the pieces in your design, then navigate to Toolpaths > 2D Path to generate the path the machine will follow.
- After ensuring the spindle is barely touching the ground, we start the machine.
After machine is done, we clean the parts and smooth them, then we arrange the bookshelf.
Result product:
