CNC Lathe

This section showcases my work with CNC lathe machining. The process involves careful tool loading and unloading, followed by using a coaxial dial indicator to align the tool holder to the spindle centerline for precise cuts, and dialing the tool on the X and Z axis. See how mistakes were made, and how they were fixed. I used the HAAS ST-10Y machine for this project.

Tool changing on the CNC Lathe

To remove a tool on the HAAS ST10Y, we first make the tool more accessible by bringing up the tool that is adjacent to the one we're removing. For example, if we’re removing tool 5, we bring tool 3 into position.
Next, we unscrew the two screws securing the tool, then gently tap it out with a mallet, as the tool is held in place by a wedge. After that, we remove the coolant sprayer by unscrewing the two screws and lifting it off the magnet.
Once the tool is removed, we load the replacement tool to further understand and perfect the CNC lathe tool-changing process. We have experience handling both axial and co-axial tools, ensuring each is loaded and unloaded with precision.

What are Axial, Co-Axial, and Radial tools?

Axial Tools: These tools are designed to cut along the axis of the spindle, typically for tasks like turning, facing, or drilling. The cutting edge is aligned with the spindle’s rotation axis, meaning the tool engages the workpiece in a straight line, primarily focusing on the material's surface along the length of the part.
Co-Axial Tools: These tools are designed to work with multiple axes simultaneously. For example, a co-axial tool can engage both the radial (side) and axial (length) directions to perform more complex operations like milling or drilling at an angle. The key feature is that the tool’s cutting edges are aligned along the same centerline, allowing for precision in tasks that require both depth and side cutting in one motion.
Radial Tools: Radial tools cut along the radius of the workpiece. The cutting edge is positioned at a right angle to the centerline of the spindle, so the tool cuts from the side, usually for tasks like side milling or profiling. Radial tools are great for working on the outer surfaces of a part.

Dialing X Axis To Spindle Center Line

We dialed in the tool on the X-axis by placing a 5-thou thick metal piece between the tool and the part. We carefully adjusted the position until the tool was pinched slightly between the metal piece and the part, allowing just a small amount of movement. Once the tool was properly aligned, we input the offset into our workspace, then subtracted the part's radius to ensure accurate positioning for the machining process.

Dialing Z Axis

We then dialed in the Z-axis using a 123 block. We positioned the 123 block against the wall of the chuck, with the 3-inch side pointing towards the tool. Carefully, we began to creep the tool towards the 123 block, slowly rotating the chuck back and forth until the tool just barely made contact with the block.

This process required extra caution to avoid crashing the 123 block into the insert of the tool, which unfortunately happened during my first attempt, resulting in a chipped insert. After replacing the insert, I continued the procedure, ensuring the tool only made a light contact with the 123 block. Once I had it dialed in to barely catch the block, I entered the offset into the workspace and subtracted 3 inches to accurately position the chuck in the Z-axis.

Dialing In Tool Holder to Spindle Centerline

We used a co-axial dial indicator to dial in the tool holder to the spindle centerline. This is a crucial step, as it ensures that when performing the center bore operation, the tool aligns perfectly with the spindle centerline, avoiding any misalignment that could affect the accuracy of the cut. The dial indicator allows for incredibly precise adjustments, helping to minimize any deviation.

Through repeated practice and fine-tuning, I was able to achieve a clearance of under a micron—well within half a tenth—demonstrating a high level of precision and consistency in the setup. This attention to detail ensures that each machining operation is executed with the utmost accuracy, contributing to the overall quality of the final part.

Changing Tool Insert

Due to the 123 block crashing into the tool insert during my first attempt, I had to replace the insert. Instead of installing a new one, I unscrewed the insert and flipped it to another side, as the insert is designed to cut on all sides. Once flipped, I carefully screwed it back into place, allowing me to continue with the setup.

Modeling The Part

I initially had trouble deciding on the design for my part, but eventually settled on a dumbbell shape. I began by modeling half of the part and then used the revolve tool to turn it into a 3D object, ensuring symmetry and precision as the design took shape.

Defining Stock and XYZ Axis

Since we were using 1-inch stock, I designed the part to be about 900 thou in diameter to allow for some facing, ensuring a smoother finish. The XYZ axes for the CNC lathe were different from those on the CNC mill, as the tool comes from the side rather than from above. To accommodate this, I made sure the Z-axis was oriented outwards, and adjusted the XY axes accordingly to ensure proper alignment during machining.

Simulating Operations

To simulate cutting my part, I began with a face cut, followed by a center bore. Next, I started a profile rough, but the cut was too aggressive. I discovered the "multiple passes" option, which reduces the tool load by taking smaller cuts. After adjusting this setting, I continued shaping the handle’s profile and used Tool 4 to make the end more spherical. I then refined the spheres to ensure they were perfect before using a grooving tool to take finer cuts as I neared the final shape. To prepare for the full cut-off, I removed more stock, creating space for the parting tool to cleanly separate the part from the chuck. Finally, I completed the process by parting off my dumbbell.

Blueprint

In this blueprint i had to point out everything from a single datum. Which was the far left as you can see. I then used Lines and the inspect tool to plot out the dimensions.

Finally cutting the part!

Before running the actual part, I performed dry runs with the "Distance to Go" screen active to ensure the tools wouldn’t collide with the chuck. During the dry run, I noticed that my tool was on track to hit the chuck, so I reconfigured the Z-axis. Once everything was properly set, I loaded the bar stock and began cutting. Throughout the process, I manually adjusted the speeds and feeds. Whenever the lathe produced an unusual noise during cutting, I fine-tuned the settings until the noise disappeared.

Problems Encountered

During the run, I didn’t realize that Tool 8 couldn’t cut sideways. Since I had programmed it for a sideways cut, it knocked the insert out of place, messing up my part.

Fix: I corrected the issue by using Tool 6 instead of Tool 8. Unfortunately, due to our tight schedule, we couldn’t rerun the part, but the program is now fixed and ready to produce a successful part.

Final Part!

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