10. Mechanical Design, Machine Design | Vinyl cutter

- Design a machine that includes mechanism + actuation + automation.
- Build the mechanical parts and operate it manually.
- Actuate and automate your machine.

- Document the group project:

Group assignment page: here.

We have made a vinyl cutter machine.

- Document your individual contribution:

Everything started with a couple of meetings with our instructors to decide the machine were going to make and schedule its development.

My individual contribution

3D design

I did a project in Fusion 360 to which I added my colleague and instructors:

I did most of this part:
- The side supports, which I worked the hardest on.
- Motor holders.
- Coupling to connect the roller with the Y axis motor.

- I modeled the motors, aluminum profiles, linear rails, rail runners, roller, and brackets.
- Since we were missing two T-nuts I have also modeled it for 3D printing.
- I have also made the 3D assembly.

• Side supports:
  

• Nema23 holder:
  
  This design offer a no-fixed position for the motor, so you can move it by a distance of 1 cm.

• T-nut:
  
  This model includes includes a pocket to introduce a M3 nut.

• Coupling:
  
  This model includes includes two pockets (one inside and another outside) to introduce M3 nuts, to adjust the motor shaft.

Roller and Cutting bed

- I have cut and sanded a metallic pipe to use it as a roller for the Y axis.

- I have glued some sandpaper to the roller for creating friction against the vinyl/paper.

- A cutting bed of a material such as nylon was needed but since we were almost out of time, I improvised a wooden bed which I attached using my 3D printed T-nuts.

- I have also cut the aluminum profiles.

3D printing

• Nema23 holder:
  
  Print summary:
  - 3D printer = Ultimaker S5.
  - Filament = 2.85 generic black PLA.
  - Nozzle = AA0.4
  - Layer height = 0.2mm
  - Wall = 1.2mm
  - Infill = 50%, Lines.
  - Support = Disabled.
  - Build plate adhesion = None.

• T-nuts:
  
  They resulted being stronger than I expected.
  Print summary:
  - 3D printer = Ultimaker S5.
  - Filament = 2.85 generic red PLA.
  - Nozzle = AA0.4
  - Layer height = 0.2mm
  - Wall = 0.8mm
  - Infill = 100%, Grid.
  - Support = Disabled.
  - Build plate adhesion = Brim.

• Coupling:

  • This is the printed part with the nuts.
    
  • This is how it looks mounted on the machine. It’s probably not the best material for this application, but it worked! 😄
    
    Print summary:
    - 3D printer = Ultimaker S5.
    - Filament = 2.85 generic black PLA.
    - Nozzle = AA0.4
    - Layer height = 0.2mm
    - Wall = 1.2mm
    - Infill = 50%, Grid.
    - Support = Disabled.
    - Build plate adhesion = None.

Computer controlled cutting

• Before making the side supports with the official material (aluminum), I have made test pieces in MDF which I laser cut.

• First goal was testing stability of the design:
  
  It was very stable, more than all of us expected.

• Secondly, these pieces serve to consider the necessary modifications:
  
  After this I have added an extra space in the back for the electronics, made holes for the X axis belt, and moved some screw holes for the brackets.

Computer controlled machining

• I prepared the g-code with my instructor using the Manufacture workspace of Fusion 360:
  
  The toolpaths used for it were:
  - Drilling - with a Ø5mm drilling tool.
  - Pocket - with a Ø6mm milling tool.
  - Contour - with a Ø6mm milling tool.

Since due to Corona-restrictions the access to the FabLab was almost impossible during these days, I have gone to Daniele Ingrassia‘s Lab for milling.

• I milled it with my instructor and then I have sanded the pieces.
  • On one of them we have mounted the motors and electronics:
    
  • While the other is rather freer:
    

Machine performance

Finally, we used a marker to make a test of its behavior:

Test result:

The small parts not drawn are because the bed is not completely flat, I have not managed to cut it evenly with the band saw. That’s also why we haven’t used the knifes and test it with vinyl.

Outlook:

- Even when the goal is making a Vinyl cutter, at this point (testing it with a marker) it works perfectly fine as a plotter machine.

- We already have the knives for cutting (also the Z axis mechanism was already designed to use the knives), but current the not-uniform bed could lead them to damage and also wood is not the best material for it.

- Later we’ll change the bed and use the knives to make the machine cut vinyl.

Files

- Nema23Holder.stl
- T-nut.stl for 30x30 aluminum profiles.
- Fusion 3D model: VinylCutter.f3z.
- Fusion project link.

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Last update: June 21, 2021