CNC turning · Hydraulic cylinder piston rod
A hydraulic piston rod needs grooves near one end, where the piston fits on. Depending on the design they hold a retaining ring, a split collar or a static seal. A CNC lathe cuts them automatically: the operator loads the rod and a short G-code program moves the tool. Press play, or step through one line at a time.
CNC stands for computer numerical control. It is a lathe whose handwheels have been replaced by motors that a computer drives. The highlighted boxes show which parts are working at the current step.
Lines of G-code, written by a programmer or generated by CAM software from the part drawing.
Reads one block at a time and works out where each axis must be, thousands of times a second.
Amplifiers that turn the controller's small command signals into motor current.
Each axis has a servo motor turning a ball screw, which pushes its slide in a straight line.
The turret moves in X, toward the rod's centre, and in Z, along the rod.
S800 M03 M05T0202M08 M09foot pedal| Code | Meaning |
|---|---|
G00 | Rapid move at full speed. Used only in the air, never into metal. |
G01 | Feed move at a controlled rate set by F. This is the cutting move. |
G04 P500 | Dwell: hold position for 500 ms while the spindle keeps turning. |
G28 U0 W0 | Return to the machine's home (reference) position. |
G97 / G99 | Fixed spindle speed in rev/min / feed in mm per revolution. |
T0202 | Tool in turret station 2, using offset set 2. |
M03 / M05 | Spindle on (forward) / spindle stop. |
M08 / M09 | Coolant on / coolant off. |
M30 | End of program, rewind to the start. |
X Z | Target position. X is the diameter, Z the distance from the end face. |
S F | Spindle speed (800 rev/min) and feed (0.05 mm/rev). |
| Groove | From end face | Diameter | Width | Depth |
|---|---|---|---|---|
| 1 | 12.0–15.0 | Ø44.0 | 3.0 | 3.0 |
| 2 | 30.0–33.0 | Ø45.0 | 3.0 | 2.5 |
| 3 | 48.0–51.0 | Ø44.0 | 3.0 | 3.0 |
Rod: Ø50.0 mm, hard-chrome plated. All sizes in millimetres. These dimensions are an example; the part drawing for your cylinder sets the real ones.
Cutting speed at S800 on a Ø50 rod: π × 50 × 800 ÷ 1000 ≈ 126 m/min. At F0.05 the tool advances 40 mm/min, so each 3 mm plunge takes a few seconds.