When turning mental allowance bigger, when needing feed cutting treatment for many times, can use circular instruction to write machine program, can reduce the amount of block so, shorten process designing time and improve work efficiency of numerical control machine tool. The circular line that machines according to cutting tool cutting is diverse, circular instruction can be divided for onefold and fixed loop instruction and multiple and compound loop dictate.

Onefold and fixed loop dictates

Simple to processing geometrical form, cutting tool takes the work with cutter track single line, can use process designing of fixed loop instruction, need to use an an instruction, block to complete the much pace action of cutting tool only namely. The motion that secures the cutting tool in dictating circularly divides a pace: Feed, cutting, retreat knife and return.

1.Round cutting dictates circularly outside (G90)

Statement form G90 X (U) _ Z (W) _ R_ F_

Instruction function Round cutting circulates outside implementation and cone cutting circulates, cutting tool presses a plan from circular start 1 with the graph 2 show cutter track line, return circular start finally, the dotted line in the graph expresses to move quickly by R, solid line states the workpiece feed rate that assigns by F is floating.

Graph 1 outside round cutting circulates

Graph 2 cone cutting circulates

The instruction explains X, Z states coordinate is worth cutting terminus;

U, W states cutting terminus circulates relatively the coordinate heft of start;

R expresses cutting only then dot and cutting terminus are in the coordinate increment of X axis direction (radius is worth) , the R when round cutting circulates outside is 0, can omit;

F shows feed rate.

Example 1 show 3 times like the graph, process designing of instruction of loop of cutting of the circle outside applying.

Graph 3 outside round cutting applies circularly

G90 X40 Z20 F30 A-B-C-D-A

A-E-F-D-A of of of of of of X30

A-G-H-D-A of of of of of of X20

Example 2 show 4 times like the graph, apply process designing of instruction of cone cutting loop.

Graph 4 Cone cutting applies circularly

G90 X40 Z20 R-5 F30 A-B-C-D-A

A-E-F-D-A of of of of of of X30

A-G-H-D-A of of of of of of X20

2. End panel cutting dictates circularly (G94)

Statement form G94 X (U) _ Z (W) _ R_ F_

Instruction function Loop of cutting of implementation end panel and the end panel cutting that take taper circulate, cutting tool from circular start, by the graph 5 with the graph 6 show cutter track line, return circular start finally, the dotted line in the graph expresses to move quickly by R, the feed rate that solid line assigns by F is floating.

Graph cutting of 5 end panel circulates

Graph 6 The end panel cutting that takes taper circulates

The instruction explains X, Z states coordinate is worth terminus of transverse plane cutting;

U, W states terminus of end panel cutting circulates relatively the coordinate heft of start;

R expresses end panel cutting only then the dot is in to cutting terminus displacement the coordinate increment of Z axis direction, the R when end panel cutting circulates is 0, can omit;

F shows feed rate.

Example 3 show 7 times like the graph, apply process designing of instruction of loop of end panel cutting.

Graph cutting of 7 end panel applies circularly

G94 X20 Z16 F30 A-B-C-D-A

of of of of Z13 A-E-F-D-A

of of of Z10 A-G-H-D-A

Example 4 show 8 times like the graph, apply take process designing of instruction of loop of cutting of taper end panel.

Graph 8 The end panel cutting that takes taper applies circularly

G94 X20 Z34 R-4 F30 A-B-C-D-A

of Z32 A-E-F-D-A

of of of of Z29 A-G-H-D-A

3. Whorl cutting dictates circularly (G92)

Statement form G92 X (U) _ Z (W) _ R_ F_

Instruction function Cutting cylinder whorl and awl whorl, cutting tool from circular start, by the graph 9 with the graph 10 show cutter track line, return circular start finally, the dotted line in the graph expresses to move quickly by R, the feed rate that solid line assigns by F is floating.

Graph whorl of 9 cutting cylinder

Graph whorl of 10 cutting awl

The instruction explains X, Z states coordinate is worth whorl terminus;

U, W states whorl terminus circulates relatively the coordinate heft of start;

R shows awl thread only then dot and terminus are in the coordinate increment of X axis direction (radius is worth) , the R when columnar whorl cutting circulates is 0, can omit;

F shows whorl lead.

Example 5 show 11 times like the graph, apply process designing of instruction of loop of columnar whorl cutting.

Graph cutting of 11 columnar whorl applies circularly

G50 X100 Z50

G97 S300

T0101 M03

G00 X35 Z3

G92 X29.2 Z-21 F1.5

X28.6

X28.2

X28.04

G00 X100 Z50 T0000 M05