G00 positioning
1. Format G00 X_ Z_ This command moves the tool from the current position to the position specified by the command (in absolute coordinate mode), or to a certain distance (in incremental coordinate mode). 2. Positioning in the form of non-linear cutting Our definition is: use an independent rapid traverse rate to determine the position of each axis. The tool path is not a straight line, and the machine axes stop at the positions specified by the commands in sequence according to the order of arrival. 3. Linear positioning The tool path is similar to linear cutting (G01), positioning at the required position in the shortest time (not exceeding the rapid traverse rate of each axis). 4. Example N10 G0 X100 Z65
G01 Linear interpolation
1. Format G01 X(U)_ Z(W)_ F_ ; Linear interpolation moves from the current position to the command position in a straight line and at the command-given movement rate. X, Z: The absolute coordinates of the position to be moved to. U,W: Incremental coordinates of the position to be moved to.
2. Example ① Absolute coordinate program G01 X50. Z75. F0.2 ;X100.; ② Incremental coordinate program G01 U0.0 W-75. F0.2 ;U50.
Circular interpolation (G02, G03)
Format G02(G03) X(U)__Z(W)__I__K__F__ ;G02(G03) X(U)__Z(W)__R__F__ ; G02 – clockwise (CW) G03 – counterclockwise (CCW)X, Z – in the coordinate system End point U, W – the distance between the start point and the end point I, K – the vector (radius value) from the start point to the center point R – the arc range (maximum 180 degrees). 2. Example ① Absolute coordinate system program G02 X100. Z90. I50. K0. F0.2 or G02 X100. Z90. R50. F02; ② Incremental coordinate system program G02 U20. W-30. I50. K0. F0.2 ;or G02 U20.W-30.R50.F0.2;
Second origin return (G30)
The coordinate system can be set with the second origin function. 1. Set the coordinates of the starting point of the tool with parameters (a, b). Points “a” and “b” are the distances between the machine origin and the starting point of the tool. 2. When programming, use G30 command instead of G50 to set the coordinate system. 3. After executing the return to the first origin, regardless of the actual position of the tool, the tool will move to the second origin when this command is encountered. 4. Tool replacement is also performed at the second origin.
Thread cutting (G32)
1. Format G32 X(U)__Z(W)__F__ ; G32 X(U)__Z(W)__E__ ; F – thread lead setting E – thread pitch (mm) When programming the thread cutting program, the RPM of the spindle speed should be uniformly controlled function (G97), and some characteristics of the threaded part should be considered. The movement speed control and spindle speed control functions will be ignored in the thread cutting mode. And when the feed hold button works, its moving process stops after completing a cutting cycle.
2. Example G00 X29.4; (1 cycle cutting) G32 Z-23. F0.2; G00 X32; Z4.; X29.; (2 cycle cutting) G32 Z-23. F0.2; G00 X32.; Z4 .
Tool diameter offset function (G40/G41/G42)
1. Format G41 X_ Z_;G42 X_ Z_;
When the cutting edge is sharp, the cutting process follows the shape specified by the program without problems. However, the real tool edge is formed by a circular arc (tool nose radius). As shown in the figure above, the tool nose radius will cause errors in the case of circular interpolation and tapping.
2. Bias function
command cutting position toolpath
G40 cancels the movement of the tool according to the programmed path
G41 Right The tool moves from the left side of the programmed path
G42 Left The tool moves from the right side of the programmed path
The principle of compensation depends on the movement of the center of the tool nose arc, which always does not coincide with the radius vector in the normal direction of the cutting surface. Therefore, the reference point for compensation is the tool nose center. Usually, the compensation of tool length and tool nose radius is based on an imaginary cutting edge, which brings some difficulties to the measurement. Applying this principle to tool compensation, the tool length, tool nose radius R, and tool nose form number (0-9) required for imaginary tool nose radius compensation should be measured with the reference points of X and Z respectively. These should be entered into the tool offset file in advance.
“Tool nose radius offset” should be commanded or canceled with G00 or G01 function. Whether this command is with circular interpolation or not, the tool will not move correctly, causing it to gradually deviate from the executed path. Therefore, the tool nose radius offset command should be completed before the cutting process is started; and the overcut phenomenon caused by starting the tool from the outside of the workpiece can be prevented. On the contrary, after the cutting process, use the move command to perform the cancel process of the offset
Workpiece coordinate system selection (G54-G59)
1. Format G54 X_ Z_; 2. The function uses G54 – G59 commands to assign an arbitrary point in the machine tool coordinate system (the workpiece origin offset value) to the parameters 1221 – 1226, and set the workpiece coordinate system (1-6) . This parameter corresponds to the G code as follows: Workpiece coordinate system 1 (G54) — Workpiece origin return offset value — Parameter 1221 Workpiece coordinate system 2 (G55) — Workpiece origin return offset value — Parameter 1222 workpiece coordinate system 3 (G56) — workpiece origin return offset value — parameter 1223 workpiece coordinate system 4 (G57) — workpiece origin return offset value — parameter 1224 workpiece coordinate system 5 (G58 ) — Offset value of workpiece origin return — Parameter 1225 Workpiece coordinate system 6 (G59) — Offset value of workpiece origin return — Parameter 1226 After the power is turned on and the origin return is completed, the system automatically selects Workpiece coordinate system 1 (G54). These coordinates will remain in effect until they are changed by a “modal” command. In addition to these setting steps, there is another parameter in the system that can change the parameters of G54~G59 immediately. The origin offset value outside the workpiece can be transferred with parameter No. 1220.
Finishing cycle (G70)
1. Format G70 P(ns) Q(nf) ns: The first segment number of the finishing shape program. nf: The last segment number of the finishing shape program 2. Function After rough turning with G71, G72 or G73, finish turning with G70.
Rough car canned cycle in outer garden (G71)
1. Format G71U(△d)R(e)G71P(ns)Q(nf)U(△u)W(△w)F(f)S(s)T(t)N(ns)……… ….F__ specifies the movement command between A and B in the program segment from sequence number ns to nf. .S__.T__N(nf)…△d: The cutting depth (radius specification) does not specify the positive and negative signs. The cutting direction is determined according to the direction of AA’, and it will not change until another value is specified. FANUC system parameter (NO.0717) specifies. e: Tool retraction stroke This specification is a state specification, and it will not change until another value is specified. FANUC system parameter (NO.0718) specifies. ns: The first segment number of the finishing shape program. nf: The last segment number of the finishing shape program. △u: The distance and direction of the reserve for finishing machining in the X direction. (diameter/radius) △w: the distance and direction of the reserved amount for finishing machining in the Z direction.
2. Function If you use the program to determine the finishing shape from A to A’ to B in the figure below, use △d (cutting depth) to cut off the designated area, and leave the finishing allowance △u/2 and △w.
Face turning canned cycle (G72)
1. Format G72W（△d）R(e) G72P(ns)Q(nf)U(△u)W(△w)F(f)S(s)T(t) △t,e,ns,nf , △u, △w, f, s and t have the same meanings as G71. 2. Function As shown in the figure below, this cycle is the same as G71 except that it is parallel to the X axis.
Forming processing compound cycle (G73)
1. Format G73U(△i)W(△k)R(d)G73P(ns)Q(nf)U(△u)W(△w)F(f)S(s)T(t)N(ns )…………………… Block number N(nf) along A A’ B………△i: Tool retract distance in X-axis direction (radius specification), specified by FANUC system parameter (NO.0719). △k: Tool retract distance in Z-axis direction (specified by radius), specified by FANUC system parameter (NO.0720). d: Dividing times This value is the same as rough machining repetition times, specified by FANUC system parameter (NO.0719). ns: The first segment number of the finishing shape program. nf: The last segment number of the finishing shape program. △u: The distance and direction of the reserve for finishing machining in the X direction. (diameter/radius) △w: the distance and direction of the reserved amount for finishing machining in the Z direction.
2. Function This function is used to repeatedly cut a gradually changing fixed form. This cycle can effectively cut a CNC machining parts and CNC turning parts that have been processed by rough machining or casting.
Face pecking drilling cycle (G74)
1. Format G74 R(e); G74 X(u) Z(w) P(△i) Q(△k) R(△d) F(f) e: Backward amount This designation is the status designation, in another Values are not changed until specified. FANUC system parameter (NO.0722) specifies. x: X coordinate of point B u: increment from a to b z: Z coordinate of point c w: increment from A to C △i: movement amount in X direction △k: movement amount in Z direction △d: in The amount by which the tool retracts at the bottom of the cut. The symbol of △d must be (+). However, if X (U) and △I are omitted, the tool retraction amount can be specified with the desired sign. f: Feed rate: 2. Function As shown in the figure below, the cutting can be processed in this cycle. If X (U) and P are omitted, the operation will only be performed on the Z axis, which is used for drilling.
Outer diameter/inner diameter pecking drilling cycle (G75)
1. Format G75 R(e); G75 X(u) Z(w) P(△i) Q(△k) R(△d) F(f) 2. Function The following commands operate as shown in the figure below, except X Using Z instead of outside is the same as G74. In this cycle, the cutting can be handled, and the X-axis cutting groove and X-axis pecking drilling can be performed.
Thread cutting cycle (G76)
1. Format G76 P(m)(r)(a) Q(△dmin) R(d)G76 X(u) Z(w) R(i) P(k) Q(△d) F(f)m : Finishing repetition times (1 to 99) This designation is a status designation, and it will not change until another value is designated. FANUC system parameter (NO.0723) specifies. r: angle to angle This specification is a state specification, and it will not change until another value is specified. FANUC system parameter (NO.0109) specifies. a: Tool nose angle: 80 degrees, 60 degrees, 55 degrees, 30 degrees, 29 degrees, 0 degrees can be selected, specified by 2 digits. This designation is a status designation and will not change until another value is designated. FANUC system parameter (NO.0724) specifies. Such as: P (02/m, 12/r, 60/a) △dmin: the minimum cutting depth This specification is a state specification, and it will not change until another value is specified. FANUC system parameter (NO.0726) specifies. i: Radius difference of the threaded part If i=0, it can be used for general linear thread cutting. k: Thread height This value is specified with a radius value in the X-axis direction. △d: first cutting depth (radius value) l: thread lead (with G32)
2. Functional thread cutting cycle.
Cutting cycle for inner and outer diameters (G90)
1. Format Linear cutting cycle: G90 X(U)___Z(W)___F___ ; Press the switch to enter the single block mode, and the operation completes the cycle operation of the path 1→2→3→4 as shown in the figure. The sign (+/-) of U and W is changed according to the direction of 1 and 2 in the incremental coordinate program. Cone cutting cycle: G90 X(U)___Z(W)___R___ F___ ; The “R” value of the cone must be specified. The use of the cutting function is similar to the linear cutting cycle.
2. Function outer circle cutting cycle. 1. U<0, W<0, R<02. U>0, W<0, R>03. U<0, W<0, R>04. U>0, W<0, R<0
Thread cutting cycle (G92)
1. Format Straight thread cutting cycle: G92 X(U)___Z(W)___F___ ; Thread range and spindle RPM stabilization control (G97) is similar to G32 (thread cutting). In this thread cutting cycle, the retracting tool for thread cutting may be operated as [Fig. 9-9]; the chamfer length is set as 0.1L unit in the range of 0.1L~12.7L according to the assigned parameter. Tapered thread cutting cycle: G92 X(U)___Z(W)___R___F___ ; 2. Function Thread cutting cycle
Step cutting cycle (G94)
1. Format Terrace cutting cycle: G94 X(U)___Z(W)___F___ ; Taper step cutting cycle: G94 X(U)___Z(W)___R___ F___ ; 2. Function Step cutting Linear speed control (G96, G97)
The NC lathe divides the speed into, for example, low-speed and high-speed areas by adjusting the step and modifying the RPM; the speed in each area can be changed freely. The function of G96 is to perform line speed control and maintain a stable cutting rate by only changing the RPM to control the corresponding workpiece diameter change. The function of G97 is to cancel the line speed control and only control the stability of RPM.
Set displacement (G98/G99)
The cutting displacement can be assigned displacement per minute (mm/min) with G98 code, or displacement per revolution (mm/rev) with G99 code; here G99 displacement per revolution is used for programming in NC lathe. Travel rate per minute (mm/min) = Displacement rate per revolution (mm/rev) x Spindle RPM
Many instructions often used in machining centers are the same as CNC machining parts, CNC turning parts and CNC Milling parts, and will not be described here. The following only introduces some instructions reflecting the characteristics of the machining center:
1. Exact stop check command G09
Instruction format: G09;
The tool will continue to execute the next program segment after decelerating and positioning accurately before reaching the end point, which can be used for machining parts with sharp edges and corners.
2. Tool offset setting command G10
Instruction format: G10P_R_;
P: command offset number; R: offset
Tool offset can be set by program setting.
3. Unidirectional positioning command G60
Instruction format: G60 X_Y_Z_;
X, Y, and Z are the coordinates of the end point that need to achieve precise positioning.
For hole processing that requires precise positioning, use this command to enable the machine tool to achieve unidirectional positioning, thereby eliminating the machining error caused by the backlash. The positioning direction and overshoot amount are set by parameters.
4. Exact stop check mode command G61
Instruction format: G61;
This command is a modal command, and in G61 mode, it is equivalent to every block of program containing G09 command.
5. Continuous cutting mode command G64
Instruction format: G64;
This instruction is a modal instruction, and it is also the default state of the machine tool. After the tool moves to the end point of the instruction, it will continue to execute the next block without deceleration, and will not affect the positioning or verification in G00, G60, and G09. When canceling the G61 mode To use G64.
6. Automatic reference point return command G27, G28, G29
(1) Return to the reference point check command G27
Instruction format: G27;
X, Y, and Z are the coordinate values of the reference point in the workpiece coordinate system, which can be used to check whether the tool can be positioned on the reference point.
Under this instruction, the commanded axis returns to the reference point with rapid movement, automatically decelerates and performs a positioning check at the specified coordinate value. If the reference point is positioned, the reference point signal light of the axis is on; if it is not consistent, the program will check again. .
(2) Automatic reference point return command G28
Instruction format: G28 X_Y_Z_;
X, Y, and Z are the coordinates of the middle point, which can be set arbitrarily. The machine tool moves to this point first, and then returns to the reference point.
The purpose of setting the intermediate point is to prevent the tool from interfering with the workpiece or fixture when it returns to the reference point.
Example: N1 G90 X100.0 Y200.0 Z300.0
N2 G28 X400.0 Y500.0; (the middle point is 400.0,500.0)
N3 G28 Z600.0; (the middle point is 400.0, 500.0, 600.0)
(3) Automatically return from the reference point to G29
Instruction format: G29 X_Y_Z_;
X, Y, Z are the returned end point coordinates
During the returning process, the tool moves from any position to the intermediate point determined by G28, and then moves to the end point. G28 and G29 are generally used in pairs, and G28 and G00 can also be used in pairs.
Post time: Jan-02-2023