A lathe is a machine tool that rotates a workpiece about an axis of rotation to perform various operations such as zeroing, shaving, facing, cutting, tapping, drilling/boring, and turning down with tools that are applied to the workpiece to create an object with symmetry about that axis.

Stock Types

  • Hex 
  • ThunderHex
  • Round Stock

The difference between hex and thunderhex is the roundness of the edge. Hex has sharp pointy edges while thunderhex is more flat and rounded on its edges. We primarily use thunderhex because we use thunderhex bearings.

We have ½” and ⅜” stock. This means the outside diameter of the part is one of these widths, respectively. On round stock, you can measure this diameter from anywhere, but on hex and thunderhex stock, this diameter can be seen by measuring from opposite flat edges.




Reading a Part Drawing

This diagram shows each of the dimensions required to read and effectively use a part drawing.

Important:

  1. The outer diameter (OD) will tell you what size shaft you need to use.
  2. The inner diameter (ID) will tell you the size of the hole of the shaft, make sure your part ID matches the drawing ID.
  3. The tolerance will tell you how much your part length can be off. If your part is not within the tolerance given by the part drawing, you will need to do one of the two things listed:
    1. If it's too short, you’ll need to redo your part.
    2. If it's too long, you can face/shave it down to length.


Safety Precautions

  1. Never use gloves while operating the lathe because it may get caught.
  2. Hair tied back, safety glasses, make sure nothing loose is dangling over the lathe (e.g. hoodie strings, baggy clothes, jewelry).
  3. Keep hands and body a safe distance from the cutting line and spinning parts on the lathe.
  4. Be cautious of heat: The metal stock gets very hot quickly.
  5. Always remove the tightening key from the chuck before starting the machine.
  6. Ensure the lathe spins towards you when turned on.


Machine Setup and Operation

Turning on the Machine

Blue Lathe

Silver Lathe

Turn the knob down.

Turn the knob to 1.

Flip the switch to 1.

Flip the switch to 1.

Pull out the emergency-stop AKA the e-stop or red button (this goes for both lathes.) Push the green button and make sure it is lit up, and turn the black knob (right of the green button) to the LEFT.

Pull the red lever out and down and make sure the lathe is spinning towards you. NEVER let the lathe spin away from you.

The x axis corresponds to a forward and back movement, and the y axis corresponds to a side to side movement. This is consistent for both lathes, however keep in mind that the y axis on the blue lathe is referred to as the z axis on the silver lathe. Moving the x axis knob clockwise results in a forward movement, and moving the y/z axis clockwise results in a right movement.

Speed Settings

Basic Operations


Zeroing the Z/Y-Axis and X-Axis

Preparation


Reminders

X-Axis Zeroing

  1. Slowly move the cutting tool towards the workpiece in the X-axis (radial direction).
  2. Approach the surface of the workpiece very carefully.
  3. Continue advancing the tool until you see very small chips forming.
  4. This point of contact is your zero reference for the X-axis.
  5. Set the X-axis digital readout (DRO) to zero at this point, if your lathe has one.

Z/Y-Axis Zeroing

  1. Move the cutting tool to the end of the workpiece.
  2. Slowly advance the tool in the Z-axis (along the length of the workpiece).
  3. Approach the face of the workpiece very carefully.
  4. Continue advancing until you see very small chips forming.
  5. This point of contact is your zero reference for the Z-axis.
  6. Set the Z-axis DRO to zero at this point, if available.


Shaving and Facing

Preparation


Shaving

  1. Position the cutting tool approximately 0.01-.03 inches inward of the part.
  2. Slowly rotate the x-axis handwheel clockwise to move the cutting tool towards the part. Maintain a consistent speed for the most accurate and clean results.
  3. Cut in 0.01-.03 increments until you reach the middle of the part on the x-axis.
  4. Once at the midpoint, stop the cutting process.
  5. Rotate the Z-axis handwheel clockwise to move the cutting tool away from the part, ensuring clearance.


Facing


Tapping

Preparation

  • The process of tapping creates threads so screws can be inserted into parts. 
  • Make sure you have tapping fluid ready.
  • Insert your tap into the teeth of the tap wrench and twist the body of the wrench till the tap is tight.
  • Place the red handled c-shaped wrench on the chuck and pull down hard to make sure the tap wrench is placed securely.
  • Make sure the lever on the side end of the lathe is pushed all the way in. This is SUPER important to ensure there is no damage to the tap or part. You can even hold it in place when you are tapping to make sure it stays in place.


Steps

  1. Place your part at least 70% in the lathe.
  2. Turn the speed setting to the lowest. This is essential, as going too fast will likely break or weaken the tap as they are very fragile.
  3. Turn the black knob left and push the entire chuck mechanism gently towards your part until the tip of the tap is just against your part.
  4. Slowly turn the wheel (pictured) clockwise until the chuck mechanism starts moving into the part on its own.
  5. Once you’ve tapped halfway to the tap length, turn the black knob back to the center. 
  6. Turn the black knob to the right to take the tap out of the part (this is the ONLY time the lathe should ever spin away from you).
  7. Clean the tap and part with air.
  8. Repeat this process, this time going all the way to your desired length.
  9. Repeat this once again to ensure clear threads.

Tips and Best Practices