To properly load a cutting tool into a CNC mill, the following steps should be taken:

1. 1. Inspect the toolholder for any damage or debris. Clean and lubricate it if necessary.

   2. Inspect the cutting tool for any damage or wear. Replace it if necessary.

   3. Verify that the tool is securely clamped and has the proper stickout/clearances

   4. Verify that the machine is in the proper mode and that the spindle is not rotating.

   5. Unload any toolholders currently loaded in the spindle, or move to an open toolchanger position.

   6. Load the new tool into the spindle, ensuring it is in the correct orientation (as needed)

   7. Clear any former tool offsets, and enter the new tool's offset values on the control panel of the CNC Mill

   8. Check/Verify the tool offsets are correct

Tool Offsets exist to let the CNC Machine know the cutting location of the Tool Tip (Tool Height Offset), as well as the cutting location of the tool’s edges (Tool Diameter/Radius Offset)

Without Tool Offsets, the machine does not know the length or diameter of the tools it uses to cut parts

• Most of the time this results in the CNC machine alarming due to programmed movements exceeding the travel limits of the machine

• In the worst-case scenarios, this can result in tool/part/fixture/machine crashes

Tool Offsets can be set anywhere on the machine, the location of which is called the “Tool Height Offset Reference Location” (THORL)

• CRITICAL: All Tool Height Offsets must be set at the EXACT SAME THORL

• Best practice is to pick a THORL that is consistent & unchanging from part-to-part, program-to-program, etc.

  • Raw (unmachined) surfaces are typically bad THORL’s, as they change once machined & are inconsistent part-to-part

  • When setting manual offsets, the most consistent & accessible location is often the top of the Machine table base

  • Rather than touch tool tips off at the top of the machine table, you touch-off on something sitting on top of the table, such as a

  • When using Tool Height Pre-setting Machines (Zoller, Haas, etc.), the THORL is located at Machine Z0.0

Get with your instructor to see which machine you will be working on this quarter, then on that machine do the following:

• Load the following tools into the tool changer:

  • (T1 = 2.0" FACE MILL, 5FL, IC)

  • (T2 = 0.375" FLAT EM, 3FL, SC)

  • (T3 = 0.500" SPOT DRILL, 2FL, SC)

  • (T4 = 0.3906" JOBBER DRILL, 2FL, HSS)

• Safely & correctly load & dial-in a dual-station vise, following the procedures outlined above

• Cut & load the following piece of raw stock into the vise, with the following specs:

  • (STOCK = 1.000" X 2.000" X 4.125" 6061-T6 AL)

  • (PART ORIENTATION: X=4.125", Y=2.000", Z=1.000")

  • (CLEARANCE = 0.125" OF PART HELD BELOW JAW TOP)

• Once done, create a "CNC Mill Operation" Project page on your portfolio website, and upload documentation your progress, including:

  • Pictures(s)/Gif(s) and/or Summaries/Descriptions of:

    • Loading the tools

    • Loading & Dialing-in the Vise

    • Prepping & Loading the raw Stock in the Vise

    • Descriptions/summaries of what you did/learned, including any mistakes/learning moments during this task