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7. Computer controlled machining

group assignment - do your lab’s safety training - test runout, alignment, fixturing, speeds, feeds, materials, and toolpaths for your machine individual assignment - make (design+mill+assemble) something big (~meter-scale) - extra credit: don’t use fasteners or glue - extra credit: include curved surfaces

group assignment

1.safety training

I. Pre-Operation Preparation

Personal Protective Equipment (PPE) (Mandatory)
✅ Safety glasses, steel-toe shoes, fitted workwear, earplugs (if in a noisy environment).
❌ Gloves: Only use during workpiece loading/unloading (strictly prohibited during machine operation to avoid entanglement in rotating parts).

Machine Status Check
- Fixture and cutting tool:
- Check that the fixture is securely clamping the workpiece.
- Ensure the cutting tool is properly installed and undamaged.
- Emergency stop button:
- Confirm its location and test functionality.

II. Safety Rules During Startup and Operation

Prohibited Actions During Operation
❌ Hands/tools entering the machining area: Even if the machine is paused, residual motion or accidental activation may cause injury.
❌ Unauthorized parameter adjustments: Do not modify critical settings (e.g., spindle speed, feed rate) without supervision.
❌ Leaving the machine unattended: Continuous monitoring is required throughout the process.

Abnormal Situation Response
- Unusual noises/vibrations/odors:
Immediately press the emergency stop button and report to the supervisor.
- Program errors:
Do not restart blindly. First diagnose the alarm (e.g., tool breakage, coordinate deviation).

III. Post-Operation Safety

Debris cleanup:
- Use dedicated tools (brushes, hooks) to clean chips — never use bare hands.

IV. Emergency Response

Sudden injury:
1. Press emergency stop →
2. Call for help →
3. Do not move the injured person (unless in immediate danger).

V. Additional Critical Reminders

  • Prohibited to operate alone:
    First-time users must be supervised by an experienced operator.
  • Stay focused:
    Avoid distractions (e.g., chatting, phone use). Keep attention on the machine’s status.

2.Design Test File

  • When CNC cutting wood panels, it is not possible to cut 90°. Therefore it is necessary to modify the corners,Generally a circle is added at right angles, with the diameter of the circle equal to the diameter of the milling head.
    Cuttingpath.jpg)

  • The first time use a CNC machine, design a test file to make sure the boards will engage just right. We are using a 12CM multilayer board. The estimated cutting error was 1MM, so holes were designed for 11.9CM, 12cm and 12.1cm. We also set 2 speeds to test the cutting effect. cnc test .dxf
    testfile.jpg)

3.machine test

We use a CNC machine(Hongtong) made in Shandong, China , its operation is different from Shopbot, this is more simple, and it has specialized software.
机器图

individual assignment - make (design+mill+assemble) something big (~meter-scale) - extra credit: don’t use fasteners or glue - extra credit: include curved surfaces