G71 O.D./I.D. Stock Removal Cycle (Group 00)

Classic Control - Lathe Operator's Manual

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G71 O.D./I.D. Stock Removal Cycle (Group 00)

*D - Depth of cut for each pass of stock removal, positive radius
*F - Feedrate in inches (mm) per minute (G98) or per revolution (G99) to use throughout G71 PQ block
*I - X-axis size and direction of G71 rough pass allowance, radius
*K - Z-axis size and direction of G71 rough pass allowance
P - Starting Block number of path to rough
Q - Ending Block number of path to rough
*S - Spindle speed to use throughout G71 PQ block
*T - Tool and offset to use throughout G71 PQ block
*U - X-axis size and direction of G71 finish allowance, diameter
*W - Z-axis size and direction of G71 finish allowance
*R1 - YASNAC select Type 2 roughing

* indicates optional

G18 Z-X plane must be active.

G71 Stock Removal: [1] Setting 73, [2] Start position, [3] Z-Axis clearance plane, [4] Finishing allowance, [5] Roughing allowance, [6] Programmed path.

This canned cycle roughs material on a part given the finished part shape. Define the shape of a part by programming the finished tool path and then use the G71 PQ block. Any F,S or T commands on the G71 line or in effect at the time of the G71 is used throughout the G71 roughing cycle. Usually a G70 call to the same PQ block definition is used to finish the shape.

Two types of machining paths are addressed with a G71 command. The first type of path (Type 1) is when the X-Axis of the programmed path does not change direction. The second type of path (Type 2) allows the X-Axis to change direction. For both Type 1 and Type 2, the programmed path of the Z-axis cannot change direction. If the P block contains only an X-Axis position, then Type 1 roughing is assumed. If the P block contains both an X-Axis and Z-Axis position, then Type 2 roughing is assumed. When in YASNAC mode, include R1 on the G71 command block to select Type 2 roughing.

note: The Z-Axis position given in the P block to specify Type 2 roughing does not have to cause axis motion. You can use the current Z-Axis position. For example, In the program example on page G71 Type 2 O.D./I.D. Stock Removal Example: [1] Start position, [P] Starting block, [Q] Ending block, [2] Finish allowance, [3] Programmed path., note that the P1 block (indicated by the comment in parentheses) contains the same Z-Axis position as the start position G00 block above.

Any one of the four quadrants of the X-Z plane can be cut by specifying address codes D, I, K, U, and W properly.

In the figures, the start position S is the position of the tool at the time of the G71 call. The Z clearance plane [3] is derived from the Z-axis start position and the sum of W and optional K finish allowance.

G71 Address Relationships

Be aware: Many service and repair procedures should be done only by authorized personnel. The service technicians at your Haas Factory Outlet (HFO) have the training, experience, and are certified to do these tasks safely and correctly. You should not do machine repair or service procedures unless you are qualified and knowledgeable about the processes.

Danger: Some service procedures can be dangerous or life-threatening. DO NOT attempt a procedure that you do not completely understand. Contact your Haas Factory Outlet (HFO) and schedule a service technician visit if you have any doubts about doing a procedure.