16. Machine Design and Machine Building¶
2020 Machine Building Group Page
My documentation is about my 2020 experiecne and contribution.
2024 Machine Building Group Page
In 2024 unfortunately I was not able to participate much since I had medical examinations but I was happy to follow our students progress and presentation.
Introduction¶
This week, our group was tasked with designing a machine that integrates mechanism, actuation, and automation. After brainstorming, we decided to create a plexiglass bending machine. My mission in this project was to do all 3d modeling and help cnc machining.
Despite the challenge of coordinating our schedules, we managed to have productive online brainstorming sessions and found common times to work in the lab.
As discussed, our project is a plexiglass bending machine inspired by a video where the bending process is done mechanically. We aimed to automate this process. Our machine features a wooden table base with two wooden pieces connected together, a hot wire to heat the plexiglass, and a DC motor to lift one of the wooden pieces to bend the plexiglass.
Key components and functionality include:¶
- A static wooden piece and a dynamic wooden piece that lifts to bend the plexiglass.
- A hot wire to heat the plexiglass.
- A DC motor to control the lifting of the dynamic piece.
- Manual angle adjustment with a protractor.
- Limit switches to detect the dynamic piece’s position.
- A push button to start the process.
- The machine stops when the dynamic piece reaches the desired angle (detected by the second limit switch) and returns to the start position.
- Potential enhancements include sound signals and an LED screen for feedback, automatic angle setting, motor speed control using a potentiometer, and the capability for multiple bendings.
Division of Work
ME : Modelling and CNC cutting of wooden parts. Integration and Assembly.
Azniv: Electronics and programming.
Joseph: 3d printing.
All: Assembly, testing, troubleshooting, fixing, and re-testing.
Workflow¶
We used a 3D-printed hinge that I designed during the 3D printing and scanning week. As the hinge was parametrically designed, I just adjusted a few dimensions to make it fit on our machine.
For the bending mechanism, I needed to design a few key parts:
- Worm gear
- Main gear
- Mount for DC motor
- Mount for worm gear
I started designing using FreeCAD. FreeCAD was new to me, and I can’t say that it has a user-friendly interface, but I can surely say that I had the best and very friendly instructor, Babken Chugaszyan. He guided me on my journey with FreeCAD.
First, I designed the main gear. We used a FreeCAD plugin that creates gears with the needed module. After the gear was ready, I cut a segment from it since we only needed half of it (180 degrees). Then, I exported it in DXF format so we could upload it into VCarve and do the machining.
The next step was designing the worm screw, which was done using the B-spline and helix tools. This part has to Be 3d printed so I exported it in stl format.
Then, I needed to design the mount for the DC motor. It involved two simple sketches: the main rectangle and the pockets.
The other mount, which does not have pockets, was designed using AutoCAD. It is supposed to keep the shaft centered.
All the 3D models that I made in FreeCAD were exported in DXF format and given to Joseph, who machined and 3D-printed them. Then, we started the assembly process. It was difficult to manage because of our mismatched schedules, but eventually, we managed it.
Conclusion¶
In conclusion, my project involved designing various parts in FreeCAD and AutoCAD, then exporting them for machining and 3D printing. Despite challenges like mismatched schedules and new software, we successfully completed the assembly with teamwork and persistence. This project provided valuable experience in design, fabrication, and collaboration.