Tool Selection Process:

Tools were selected by accessing the MDI (Manual Data Input) screen, where the tool number (e.g., T6) was chosen. After selecting the desired tool, we clicked the ATC (Automatic Tool Changer) forward button to load the tool into the machine. This process ensured that the correct tool was selected for each operation.

Tool Evaluation for Accuracy:

To ensure the tools were accurate and in good condition, we carefully reviewed each tool listed on the tool sheet. This involved:

• Checking for visible wear and tear, discoloration, or any signs of dullness in the cutter edges.

• Cycling the machine to ensure the tools were functioning properly.

• For example, Tool 3 (375 3-flute end mill) showed visible wear, so it was noted for replacement.

• Tool 4 (25 3-flute sharp corner end mill) had some discoloration on one of the blades, so we reported this to our supervisor and requested replacements for any damaged tools.

• After replacing the worn tools, we used a radius tool to check the radius of the new cutters, ensuring the gauge fit perfectly with the tool's cutting edge.

All Tools evaluated:

• T10: 5/8” 3-flute roughing cutter

• T2: 0.5” 3-flute sharp corner end mill

• T3: 0.375” 3-flute end mill

• T1: 2.0” 3-flute high shear face mill

• T16: 0.500” 3-flute end mill

• T18: 0.1875” (3/16”) 3-flute ball end mill

• T4: 0.25” 3-flute sharp corner end mill

Building a Tool in a Collet-Style Tool Holder:

To replace the worn-out tool:

1. We removed the .25 3-flute sharp corner end mill from the collet at the tool changing station.

2. Using a wrench, we loosened the collet past its two tension points to remove the old end mill.

3. After installing the new tool, we carefully touched it off by:

   • Placing the new end mill into the collet, ensuring there was enough clearance between the tool's flutes and the collet.

   • Tightening the collet with the wrench.

4. Using calipers, we measured the length of the cut to confirm it matched the tool documentation. The document specified a length of 1.25 inches, and our measurement was 1.23 inches, which was acceptable.

5. We also ensured the machine area was clean to prevent any FOD (Foreign Object Debris) from interfering during the tool-off process.

Building a Tool in a Shrink-Fit Tool Holder:

1. We selected the .25 inch sharp corner end mill and matched it to the appropriate heat level according to the tool crib sheet.

2. We used the shrink fit machine to heat the tool holder. The end mill was heated to level 4 in the heater.

3. Once the tool reached the required temperature, we removed it from the heater and quickly placed it into the chiller to cool, allowing the tool to shrink fit securely into the holder.

Shrink Fit vs. Collet-Style Tool Holders:

• Shrink Fit Tool Holder:

  • More rigid, making it suitable for higher precision and demanding machining operations.

  • Capable of handling higher RPMs (over 10,000), making it ideal for high-speed machining.

  • Can only hold tools with one specific diameter.

• Collet-Style Tool Holder:

  • Easier to remove and replace tools, making it more user-friendly.

  • More cost-effective compared to shrink fit holders.

  • More universal—can hold a range of different tool sizes.

Proper maintenance is crucial for keeping CNC machines running efficiently, prolonging their lifespan, and ensuring the accuracy and reliability of operations. Here’s a breakdown of daily, weekly, monthly, and yearly maintenance tasks, along with the specific steps taken for chip cleaning, spindle maintenance, and coolant management.

Daily Walkthrough:

Each day, it’s essential to inspect the machine to ensure everything is in proper working order:

• Coolant Check: Verify that the coolant is filled to the correct level, and ensure there are no clogs in the chip filter.

• Air Filter: Make sure the air filter is functioning properly and free of any blockages.

• Excess Heat: Monitor the machine for signs of overheating, as excess heat can cause problems.

• Lubricants: Check that all lubricants are at the correct levels.

• Machine Cleanup: At the end of each shift, it’s important to clean the machine thoroughly to remove any chips, dirt, or debris.

Daily Maintenance:

In addition to the daily walkthrough, perform these additional maintenance tasks to keep the machine in top condition:

1. Spindle Warm-Up: Begin with a spindle warm-up to ensure the spindle is running smoothly.

2. Airlines: Check the airlines for water. If there’s water in the airline, this could indicate a problem with the machine's pressure system.

3. Coolant Concentration: Measure the coolant concentration, ensuring it’s between 6-8%. If the concentration is off, adjust it.

4. Tool Inspection: Check all tools for damage or rust. If any tools are worn or damaged, replace them.

5. Chip Removal: Clear out the chips from the previous work and clean the chip filter to ensure proper coolant flow.

6. Tool Holder Cleaning: At the end of the day, remove the tool and clean the tool holder with WD-40 to maintain its functionality.

Weekly Maintenance:

Every week, inspect and maintain the following components:

1. Plungers & Worn Keys: Check for any worn plungers or keys and replace them as needed.

2. Air Regulator: Inspect the air regulator and verify it’s set correctly in alignment with the pendant.

3. Coolant Tank & Filter: Remove the coolant filter and clean out any chips trapped in the mesh. Check for excessive buildup and replace the filter if necessary.

4. Auxiliary Filter: If your machine has an auxiliary filter, inspect it and replace it as needed.

Monthly Maintenance:

At the end of each month, perform a deeper inspection and maintenance routine:

1. Tool Changer Cleaning: Clean the tool changer, particularly the area above it, to remove any chips or debris.

2. Carousel Cleaning: Remove all tools from the carousel and clean any chip buildup on the carousel plate.

3. Extractors & Motors: Check the extractors for grease and alignment issues. Inspect motors and proximity sensors for frayed wires and other potential issues.

4. Tool Arm Check: Command a blank tool change and use the E-stop to ensure the tool arm is straight and secure. This helps ensure that tools are mounted correctly.

5. Lubrication: Grease the plungers and slider caps to ensure smooth operation.

6. Rust Protection: Spray a rust protectant on the sliding parts to prevent rust buildup.

7. Air Filter Cleaning: Remove the air filter and clean it with an air hose.

8. Coolant Tank Inspection: Check the coolant tank for cleanliness and ensure there’s no chip buildup.

9. Pressure Gauge: Verify the pressure reading is at least 50 psi or 3 bar higher than the recommended value to ensure proper machine operation.

Yearly Maintenance:

A full, deep clean should be done once a year to ensure the machine remains in top condition:

1. Weight & Spindle Covers: Remove the weight covers and spindle covers to clean all areas of the machine thoroughly.

2. Deep Clean: Clean every part of the machine, including the areas that are typically hard to reach.

Chip Cleaning:

To keep the machine running efficiently, it’s important to clean out chips regularly. Follow these steps for chip removal:

1. Blow Off Chips: Use air to blow the chips off the plate.

2. Shovel Chips: If the chip augers didn’t fully remove the chips, shovel the remaining chips out manually.

3. Chip Augers: The chip augers constantly feed chips into a conveyor belt. If there’s a stoppage, the augers will reverse and try again. If there’s no sensor, you’ll need to manually declog the augers.

Spindle & Tool Maintenance:

Regular spindle and tool maintenance are key to keeping the machine performing at its best:

1. Spindle Cleaning: Use a spindle cleaner and rubbing alcohol to clean the spindle once a week. Apply the rubbing alcohol and rotate the spindle to clean all areas thoroughly.

2. Coolant Flow for Tools: Some tools feature holes that allow coolant to flow through to regulate temperature and clean out chips. Make sure these are functioning properly, especially when cutting hard metals.

3. Tool Speed & Coolant: To prolong the life of cutters, make sure the correct cutting speed and coolant are used, particularly when machining hard materials.

Coolant Tank Cleaning:

The coolant tank needs regular cleaning to prevent contamination and ensure the coolant is in good condition:

1. Draining Coolant: Use a drumvac to extract coolant from the machine. The drumvac has filters to prevent chips from entering the drum.

2. Coolant Disposal: Once the coolant is extracted, use positive airflow to transfer it to a recycling company. Always ensure the coolant is recycled properly.

3. No Cleaners: Avoid using cleaners or chemicals, as this could contaminate the coolant.

4. Coolant Filter: Clean the coolant filter thoroughly, removing all chips.

5. Coolant Concentration: Measure the coolant’s concentration using a refractometer. Add or adjust coolant to maintain the correct concentration (approximately 6-8% for optimal cooling and cutting).

6. Coolant Tank Cleaning: After draining the coolant, remove any remaining chips using a vacuum, and clean the coolant tank with a rag and cleaner.

By following this comprehensive maintenance routine, the CNC machine will run more efficiently, have fewer mechanical issues, and produce better-quality work. Consistent maintenance ensures both longevity and precision in machining operations.

Finding Offsets: Edge Finder Method vs Paper Method

Today, we explored two different methods for finding offsets on the CNC machine: the Edge Finder Method and the Paper Method. Here’s a detailed breakdown of both methods and the process we followed.

Edge Finder Method:

1. Setup:

   • We began by installing the edge finder into the chuck and locking the spindle.

   • On the pendant, we used the M19 command to lock the spindle in place, then clicked Cycle Start to initiate the procedure.

   • We set the spindle RPM to 500 for the edge finder to rotate at a consistent speed.

2. Approaching the Part:

   • We used the handle jog to move the edge finder close to the part, ensuring it was slightly above the part’s surface.

   • To avoid parallax (viewing angle distortion), I positioned myself at eye level with the tool and part for better accuracy.

3. Finding the Edge:

   • With the edge finder approaching the part, we slowly jogged it towards the material until the edge finder made contact with the part and "popped."

   • The tool’s motion when it touches the part helps to identify the edge, and once it pops, it means the edge finder is aligned with the material.

4. Calculating the Offset:

   • We then calculated the offset by subtracting half the radius of the edge finder from the measurement. The radius of the edge finder was 0.100 inches.

     • If the edge finder popped on the right side, we subtracted 0.100 from the value (since the edge finder is positioned to the right of the part).

     • If it popped on the left side, we added 0.100 to the value.

   • For example:

     • X offset: I got -10.0811 for the initial measurement. After subtracting 0.100 (half the radius), the offset became -10.1881.

     • On the other side, I got -32.3887, and after adding 0.100, the new offset was -32.2887.

Paper Method:

1. Setup:

   • We used a 2x4x6 block with a height of 6 inches and positioned the tool close to the part.

2. Touch Off with Paper:

   • The paper method involves a "stress test" by sliding a piece of paper between the tool and the part.

   • We moved the paper back and forth while lowering the tool. The goal was to have the paper slightly scratch as the tool makes contact with it.

   • Once the paper felt slight resistance, we measured the offset based on the tool's position.

3. Adjusting for Paper Thickness:

   • Since the paper we used was 3 thousandths thick (0.003 inches), we subtracted 3 thou from the tool offset value to account for the paper's thickness.

Tool Offsets (OTS):

To access the tool offsets, we followed these steps:

1. MDI Setup:

   • We navigated to MDI (Manual Data Input) mode and entered the tool number and the tool’s length and diameter.

   • A pop-up window appeared where we created a sub-program that would apply the offsets to the correct tool.

2. Setting G-Code:

   • We used G55, a work offset, to specify the position where the tool will start working.

   • After setting up the program and inputting the required parameters, we hit Cycle Start to begin the operation.

Endmill Height Reference:

• Endmills with a Radius: The highest point of an endmill with a radius is at the center of the cutter, as the radius is distributed symmetrically around the tool.

• Endmills without a Radius: For endmills without a radius, the highest point is at the very tip of the cutter, where the flutes start cutting into the material.

By the end of the day, we gained a solid understanding of how to properly find offsets using both the Edge Finder and Paper Method, ensuring that we can precisely set up our CNC operations for accurate machining.