Report.pdf | |
File Size: | 300 kb |
File Type: |
Appendix.zip | |
File Size: | 819 kb |
File Type: | zip |
3 Axis Mini CNC Mill
My senior project was to design and manufacture a small (18" by 18") 3 axis CNC milling machine from scratch. Time and funding were the large constraints put on this project. The project was a success though. A functioning prototype was designed and fabricated in under four months and the entire project was completed for under $500. The major challenges faced in designing and building a CNC mill are the locomotion of each of the axes and keeping the axes linear.
The movement of the axes was solved by using a threaded rod (1/4"-20) and threaded inserts that would be prevented from rotating with the rod. The threaded rod would be attached by a set screw to one of three (one for each axis) stepper motors. When the stepper motor would turn the threaded rod, it would cause movement of the threaded inserts.
The linearity of the axes was a much more challenging problem. This is because the slightest misalignment could cause binding in the machine. After much brainstorming, I decided to use High Density Polyethylene (HDPE) sliders. These sliders would slide along highly polished parallel rails for the X and Y axes. For the Z axis the entire Z axis block would slide between slotted HDPE.
The project was a success and using a common Dremel as a cutting tool the machine can be programmed using G-Code to etch or even cut a variety of material from plastics to Aluminum.
The movement of the axes was solved by using a threaded rod (1/4"-20) and threaded inserts that would be prevented from rotating with the rod. The threaded rod would be attached by a set screw to one of three (one for each axis) stepper motors. When the stepper motor would turn the threaded rod, it would cause movement of the threaded inserts.
The linearity of the axes was a much more challenging problem. This is because the slightest misalignment could cause binding in the machine. After much brainstorming, I decided to use High Density Polyethylene (HDPE) sliders. These sliders would slide along highly polished parallel rails for the X and Y axes. For the Z axis the entire Z axis block would slide between slotted HDPE.
The project was a success and using a common Dremel as a cutting tool the machine can be programmed using G-Code to etch or even cut a variety of material from plastics to Aluminum.