Chapter 87, Problem 28A

To determine

The CNC G-code program to machine the part.

Explanation of Solution

Given:

Tool used should be #6.

Tool starts with a rapid movement to point $\left(0,0,50\right)$ using absolute dimensioning.

Feed rate should be $2000\text{mm/min}$.

Spindle speed should be $6000\text{RPM}$.

Use of coolant is necessary.

Back to start point by rapid movement.

Program:

Draw the schematic diagram for the part as shown below:

  

To machine the part shown above the below mentioned CNC program must be used:

  $\begin{array}{l}\text{08728}\\ \text{G00 G21 G90 G17 G94 G80}\\ \text{M06 T6}\\ \text{G00 X}0\text{Y}0\text{ Z50}\\ \text{S6000 M03 M08}\\ \text{G90}\text{G00 X}-19\text{ Y0 Z50 }\\ \text{G00 Z}5\\ \text{G01 Z}-10\text{F2000}\\ \text{G01 X}-19\text{ Y38}\\ \text{G02 X}19\text{ Y38 J19}\\ \text{G01 X19 Y}0\\ \text{G0}0\text{ Z}-\text{5}\\ \text{G01 X}15\text{ Y}0\\ \text{G01 X}15\text{ Y}30\\ \text{G03}\text{X}-\text{15 Y 30 I}-15\\ \text{G01 X15 Y0}\\ \text{G00 Z50 }\\ \text{M05 M09}\\ \text{G00 X}0\text{ Y}0\\ \text{M30}\end{array}$

Here,

• 08727 is the title of program file.
• G00 is the G-code for rapid traverse.
• G21 is the G-code for unit in millimeters.
• G90 is the G-code for Absolute programming.
• G17 is for selection of XY plane.
• G94 is used for Feed per minute.
• G80 is used for cancel canned cycles.
• M06 is the machine code for tool change.
• T6 is the tool code for selection of sixth tool.
• S60000 is the Spindle code for 6000 rpm.
• M03 is the machine code for spindle start clockwise.
• M08 is the machine code for coolant ON.
• G01 is the G-code for linear interpolation.
• Code $\text{G00 X}0\text{Y}0\text{ Z50}$ moves the tool from start point to point $\left(0,0,50\right)$ which is 50 mm above the origin.
• Code $\text{G90}\text{G00 X}-19\text{ Y0 Z50}$ rapidly moves the tool to $19\text{ mm}$ left side of the origin.
• Code $\text{G00 Z}5$ linearly moves the tool down by $45\text{mm}$ .
• Code $\text{G01 Z}-10\text{F2000}$ moves the tool linearly down by $15\text{ mm}$ to start the cutting process with a feed rate of $2000\text{ mm/min}$ .
• Code $\text{G01 X}-19\text{ Y38}$ moves the tool from $\left(-19,0,-10\right)$ to $\left(-19,38,-10\right)$ linearly.
• Code $\text{G02 X}19\text{ Y38 J19}$ moves the tool in clockwise direction from point $\left(-19,38,-10\right)$ to $\left(19,38,-10\right)$ with radius of 19mm.
• Code $\text{G01 X19 Y}0$ moves the tool from point $\left(19,38,-10\right)$ to $\left(19,0,-10\right)$ linearly.
• Code $\text{G0}0\text{ Z}-\text{5}$ moves the tool rapidly above 5 mm to the point $\left(19,0,-5\right)$
• Code $\text{G01 X}15\text{ Y}0$ moves the tool from point $\left(19,0,-5\right)$ to $\left(15,0,-5\right)$ linearly.
• Code $\text{G01 X}15\text{ Y}30$ moves the tool from point $\left(15,0,-5\right)$ to $\left(15,30,-5\right)$ linearly.
• Code $\text{G03}\text{X}-\text{15 Y 30 I}-15$ moves the tool in counter clockwise direction from point $\left(15,30,-5\right)$ to $\left(-15,30,-5\right)$ with radius of 15mm.
• Code $\text{G01 X15 Y0}$ moves the tool from point $\left(-15,30,-5\right)$ to $\left(-15,0,-5\right)$ linearly.
• Code $\text{G00 Z50}$ rapidly retracts the tool 50 mm above the work piece surface.
• M05 is the machine code used to stop the spindle.
• M09 is the machine code used to turn the coolant off.
• Code $\text{G00 X}0\text{ Y}0$ moves the tool rapidly back to its start point with absolute dimensioning.
• M30 is the M-code use to stop the machine.