9.13 Slotting
Micky R. Jennings
Figure 9.164. A hand holds a rectangular part that has a finished slot cut on one end. / Image Credit: Micky R. Jennings, courtesy of Wenatchee Valley College, CC BY 4.0Slottingis the process of using an end mill to create a slot or groove in a part. A precision slot is generally performed in multiple passes, allowing the operator to adjust the machine for position and size. Attempting a slot in a single pass may result in an oversized and out-of-position slot that has a poor surface finish.
Step by step process slotting:
- Load material into a vise.
- Apply layout dye to the top of the part.
- Using odd legged calipers, scribe lines on the top of the part to indicate the position of the slot.
- Load an end mill for roughing, one size smaller than the slot, into the milling machine.
- Calculate the spindle speed and feed rate for the cut.
- Turn the spindle on and adjust the machine to the calculated speed.
- Position the machine so that the tool is visually in the center of the slot.
- Zero and lock the table handwheel.
- Touch the tool off to the top of the work.
- Set the graduated collar of the knee to zero.
- Move the saddle so the tool is off the work.
- Move the knee up the desired depth of cut, minus .015″.
- Lube the tool and the work.
- Make the initial cut through the length of the slot at the calculated feed rate.
- Take a measurement to determine the amount needed to be removed in one direction.
- Conventional cut the remaining material, leaving material on walls for finishing.
- Load a separate finishing tool if needed.
- Make a test cut just skimming the bottom and the side of the slot.
- Zero the table and knee handwheels.
- Accurately measure the part.
- Set the knee to the full depth of the slot.
- Adjust the machine and make successive cuts in order to finish one side.
- Make a skim cut on the other side of the slot.
- Zero the table handwheel.
- Measure the slot and calculate the material needed to be removed to finish the slot.
- Adjust the machine and make successive cuts in order to finish the slot.
Step 4: Load an end mill for roughing, one size smaller than the slot, into the milling machine.
Step 7: Position the machine so that the tool is visually in the center of the slot.
Step 9: Touch the tool off to the top of the work.
Step 12: Move the knee up the desired depth of cut, minus .015″.
Step 13: Lube the tool and the work.
Step 13: Lube the tool and the work.
Step 14: Make the initial cut through the length of the slot at the calculated feed rate.
Step 14: Make the initial cut through the length of the slot at the calculated feed rate.
Step 14: Make the initial cut through the length of the slot at the calculated feed rate.
Step 15: Take a measurement to determine the amount needed to be removed in one direction.
Step 16: Conventional cut the remaining material, leaving material on walls for finishing.
Step 16: Conventional cut the remaining material, leaving material on walls for finish