7. Computer Controlled Machining¶

Summary¶

Group Assignment¶

During this week, I worked with a large CNC milling machine.
The goal of this assignment was to complete safety training and test the machine’s alignment, fixturing, speeds, feeds, and toolpaths.
As part of the task, I created a wooden sign with the text “YESSENOV UNIVERSITY”.

CNC Machine Description¶

This is the CNC milling machine that I used during my assignment.
It is a large 3-axis router designed for cutting and engraving materials such as MDF, plywood, acrylic, and softwood.
The machine is controlled through NCStudio software, which reads G-code and controls the spindle and tool movement precisely along the X, Y, and Z axes.

Machine Specifications¶

Technical Safety Guidelines¶

Before operating the CNC machine, I completed safety training and learned how to handle the machine responsibly.
Here are the main safety rules that I always follow:

1. Wear protective equipment — safety glasses, ear protection, and dust mask.
2. Check the work area — ensure that there are no tools, loose objects, or hands near the spindle.
3. Secure the material properly — fix the board with screws or clamps to prevent vibration or shifting.
4. Verify the zero point (X, Y, Z) before starting the spindle.
5. Test the G-code in simulation mode to make sure the toolpath is correct.
6. Never touch the spindle or the workpiece while the machine is running.
7. Use the emergency stop button immediately in case of any abnormal noise, vibration, or movement.
8. Keep cables and tools organized to avoid tripping or accidents.
9. Wait until the spindle fully stops before removing the material.
10. Clean the workspace after each job to remove dust and wood chips.

My Notes¶

While working with the CNC, I realized how important it is to double-check all setup steps — especially zeroing and fixturing.
Even a small misalignment can ruin the entire cut.
Understanding feed rate, spindle speed, and stepdown depth also helped me achieve smooth and clean engraving results.

Milling Bits Used¶

During the machining process, I used different types of milling bits.
Each bit has its own geometry and purpose depending on the type of cut I wanted to achieve.
Experimenting with these tools helped me understand how the shape of a bit affects the final surface finish, engraving depth, and edge quality.

Types of Milling Bits I Used¶

Testing Different Feed Rates & Spindle Speeds

During group testing, we experimented with multiple spindle speeds and feed rates to compare cutting quality.

Observation

At low spindle speed + low feed rate, the cut was rough and inconsistent.

Increasing spindle speed and feed rate improved the quality.

At very high spindle speed (24,000 RPM), burn marks appeared due to friction.

The best parameters were approx. 22,000 RPM, 8 mm/s, which produced clean edges and stable cutting.

Low spindle speed + low feed rate → rough surface¶

Improved quality with moderate speed¶

High spindle speed + moderate feed → best result¶

Overheating at very high speed → burn marks

This shows how tuning parameters directly influences cut quality.

My Observation¶

While testing, I noticed that: - Flat end mills provide clean and fast cuts for text engraving.
- V-bits are best for lettering and sharp details.
- Round nose bits work well for smooth, curved surfaces.

Understanding the right tool for the job is one of the most important steps in achieving a good CNC milling result.
Using the wrong bit can easily cause rough edges, burning marks, or tool damage.

Machine Alignment Testing¶

We also tested machine alignment before milling.

Steps Performed¶

• Moved the spindle to each corner of the workspace
• Measured table flatness and height variation
• Checked squareness between X and Y axes
• Checked Z-axis zeroing consistency

Results¶

The table was reasonably flat, but the front corners were slightly higher (0.2–0.3 mm).
Because of this, when we engraved text near the front edge, the depth was slightly shallower compared to the rear.

Adjustments¶

• Compensated Z-height during setup
• Re-zeroed Z above the lowest surface point

After correction, engraving depth became more consistent across the full board.

Cutting Process¶

Before starting the cutting process, I carefully prepared the work area.
First, I selected a suitable wooden sheet and made sure its surface was flat and clean.
I drilled pilot holes using an electric drill to avoid splitting the material and then secured the board from all four corners using screws.
This step is extremely important because even a small movement of the board can completely ruin the accuracy of the cut.

Once the material was fixed properly, I began learning how to operate the NCStudio software.
This program controls the CNC machine and interprets G-code — a set of instructions that tells the machine where and how to move.
At first, NCStudio looked complicated, but after exploring it, I found it quite logical and easy to use.
The interface allows setting the origin point (X, Y, Z), adjusting the spindle speed, and simulating the toolpath before actual cutting.
This simulation step is essential to ensure the spindle doesn’t collide with clamps or exceed the working area.

To start a project, I imported my DXF file, which contained the “YESSENOV UNIVERSITY” text.
NCStudio automatically converted it into a G-code toolpath, visible on the screen as a series of coordinates and movement commands.
Each line of G-code represents a motion along the X, Y, or Z axis, defining the cutting path of the tool.

We practiced several times, testing various spindle speeds and feed rates.
At first, the cutting quality was poor — the edges were rough, and some letters were too shallow.
After several adjustments, I learned how spindle speed and feed rate affect the final result.
For example:

• Lower feed rate increases accuracy but takes longer to complete the job.

I achieved a good combination of speed and precision.

After several test runs, I finally achieved a clean and well-defined engraving.
The machine precisely followed the G-code coordinates, carving out each letter of the “YESSENOV UNIVERSITY” text.
The result had smooth edges and consistent depth, showing that the alignment, toolpath, and calibration were all correct.

This part of the assignment helped me deeply understand how a CNC machine interprets digital files and translates them into precise physical movements.
I realized that fixing the material, choosing the correct tool, and setting the right parameters are all equally important for achieving high-quality results.
Even small mistakes in setup can lead to large errors in the final cut.
Working with NCStudio gave me confidence to prepare and control CNC toolpaths independently, and this experience will be very useful for my future fabrication projects.

Conclusion¶

Through this assignment, I learned how to operate the CNC machine safely and precisely.
I practiced setting up materials, fixing them correctly, generating G-code, and running the final cut in NCStudio.
After several attempts and adjustments, I achieved a clean result with accurate engraving.
This experience helped me understand the full workflow of computer-controlled machining and gave me confidence to use CNC tools for future fabrication projects.

Individual Assignment¶

In this week’s assignment, I worked with the CNC machine to fabricate two different parts for my projects. The first part was a storage box, which I made from PVC sheet. The second part was the wooden chassis for my delivery robot, which I CNC-milled from a plywood board. Both parts were designed in Fusion , exported as toolpaths, and machined using the CNC router.

Cutting for the container and assembly¶

In this image I created the full parametric 2D sketch of the container in Fusion. I defined all dimensions, added joints, and prepared interlocking features with an 8 mm thickness, because my chosen PVC sheet was 8 mm. This sketch served as the base for CNC cutting.

Here you can see the assembled 3D model of the container in Fusion 360. Modeling the box in 3D helped me verify the fit of all joints and make sure the handles, notches, and walls align correctly before generating toolpaths.

In this step, we fixed the PVC sheet onto the CNC machine bed using super glue. This ensures the sheet does not move during milling and keeps the cut edges clean and accurate.

Before generating the toolpath, I measured the actual width and height of the PVC sheet. These dimensions are important for creating the correct workspace size in ArtCAM and positioning the layout accurately.

This photo shows ArtCAM being launched. I used ArtCAM to prepare the toolpath for the CNC machine, import my Fusion 360 file, and set up the machining operations.

Here I entered the material dimensions (width and height) inside ArtCAM. Setting the correct material size ensures that the cutting layout fits inside the actual sheet and avoids exceeding the boundaries.

In this image, I imported my vector design into ArtCAM. This vector file contains all the outlines and joints for the box panels that will be milled with the CNC machine.

This photo shows the vector layout inside ArtCAM after import. All the parts of the container are arranged properly on the sheet, ready for toolpath creation.

Here I selected the cutting tool: a 3 mm straight end mill. This bit size is ideal for cutting 8 mm PVC while keeping the slots and joints accurate.

This video shows the CNC machine cutting the container parts according to my design.

The final photo shows one of the completed CNC-cut pieces. The cut came out clean and precise, with smooth edges and accurate interlocking joints.

In this photo, you can see the G-code file successfully loaded into NC Studio. On the left, the preview shows the toolpath of the container parts, and on the right, the full list of G-code commands is displayed. At this stage, I verified the cutting paths to ensure that the CNC machine would follow the correct geometry before starting the milling process.

This image shows the assembled container after cutting the PVC sheets on the CNC machine. All the joints fit together cleanly, confirming that the parametric dimensions and tolerances were correct. This container was made only as a test piece, to check the accuracy of the machine and the quality of the cuts.

Here is a side view of the completed test container. The edges are smooth, the handle cutouts turned out clean, and the assembly is structurally solid. Again, this container is not part of my delivery robot project — it was produced purely to test CNC workflow, tool calibration, and material behavior.

Designing the Chassis in Fusion 360¶

I started by creating the design in Fusion 360.
I made a sketch of the chassis shape, including mounting holes for motors and wheel brackets.
This step helped me plan the overall structure and balance of my robot.

After finishing the design, I right-clicked on my sketch and selected Export DXF to generate the 2D file for CNC machining.

I named the file Chassis.dxf and saved it locally to my computer for the next step.

The DXF file was successfully exported and ready for machining.

Preparing the Material and Machine¶

Before cutting, I fixed the wooden board securely onto the CNC bed.
It is important to make sure the material doesn’t move during cutting to avoid any damage or misalignment.

Next, I opened NCStudio, which is the control software for the CNC machine.
I imported my DXF file and checked the feed rate, cutting speed, and toolpath simulation to make sure everything looked correct.

Cutting Process¶

I did not have dedicated holding tabs for securing the workpiece. However, I still needed to fix it properly, so I fastened the wooden board at four points using screws and a power screwdriver. This prevented the material from shifting during the milling process.

Once everything was ready, I started the cutting process.
The CNC machine followed the toolpath accurately, cutting the outline and holes of the chassis.
I ran the process several times to ensure the wood was fully cut through.

Result and Assembly¶

After finishing the machining, I carefully removed the wooden part from the CNC table.
The result was a clean and strong chassis base for my robot.

Then I started assembling the robot’s lower frame.
I installed the wheel brackets and caster wheels, checking that all bolt holes matched perfectly with my Fusion 360 design.

Finally, I attached all four wheels and secured them with bolts and nuts.
Everything fit well — the design and measurements were accurate.

¶

Here is the final result of my CNC machining project — a fully cut and assembled wooden base for my robot.
The chassis is stable, precise, and ready for the next stage of my final project development.

Conclusion¶

This week, I learned how to design and fabricate large parts using a CNC machine.
I practiced exporting DXF files from Fusion 360, setting up the material, and using NCStudio for machining.
The final wooden chassis turned out perfectly and will be used in my final robot project.
This experience gave me confidence to use CNC machining for building strong and precise mechanical components in the future.

Files for download¶

Chassis file

Container file