Welcome to our simple guide on the G73 CNC code. Whether you are new to CNC programming or an experienced machinist, understanding the G73 code is essential.
This guide will explain everything you need to know about this unit mode command—what it is, when to use it, and why it matters.
(Step-by-step.)
Key Takeaways
- G73 pattern repeating cycle is ideal for drilling complex shapes and profiles with pre-cut or cast profiles.
- G83 peck drilling cycle is used for drilling operations, particularly useful for breaking chips and clearing swarf during drilling.
- Peck drilling cycles, including G83, improve tool life, reduce the risk of tool breakage, and efficiently remove chips and debris.
- G73 cycle allows for customizable drill patterns and precise control over roughing passes, making it suitable for drilling complex shapes.
- G73 and G83 cycles can be used together to achieve rapid and precise drilling operations with improved tool life and material removal.
G73 Pattern Repeating Cycle
When you’re faced with a part that has a pre-cut or cast profile, the G73 pattern repeating cycle is the ideal solution.
This cycle cuts in the shape of the profile defined with a subroutine, allowing you to efficiently drill complex shapes. On each pass, the tool cuts the shape of the profile, indexing in both X and Z axes, with the amount of indexing defined by the values added to the first G73 line.
The cycle continues until the finished size is achieved, with the number of roughing passes specified by the R value in the first G73 line. By using the G73 cycle, you can efficiently remove material and achieve precise drilling results.
Drilling Cycles and Chip Breaking
When you’re working with general drilling operations, you’ll often turn to the G83 peck drilling cycle,
which retracts above the surface of the component after each peck, controlled by the R value.
This cycle is particularly useful for breaking chips and clearing swarf during drilling operations.
G83 Peck Drilling
During deep hole drilling operations, you frequently encounter the challenge of chip accumulation, which can lead to reduced tool life, compromised hole quality, and even tool breakage.
To mitigate this, the G83 peck drilling cycle is used to clear swarf and chips during drilling operations. This cycle retracts above the surface of the component after each peck, controlled by the R value.
- The G83 cycle is often used with high-pressure coolant to wash away chips and promote lubrication and cooling.
- It can be used for deep hole drilling and drilling hard materials.
- The retract value (R) controls the height of retraction above the surface or within the hole.
- The dwell time (P) can be used to clean up the bottom of the hole, especially for blind holes.
The format for the G83 peck drilling cycle is G83 X Y Z R P Q F, where F specifies the feed rate.
Chip Breaking Techniques
You’ve likely encountered the limitations of traditional drilling cycles in regard to managing chip accumulation.
This is where the G73 pattern repeating roughing cycle comes in, specifically designed for chip breaking techniques in drilling cycles.
To clear swarf and chips during drilling operations, high-pressure coolant can be used to wash them away and promote lubrication and cooling.
In peck drilling cycles, the retract value (R) controls the height of retraction, helping to break chips.
Dwell time (P) can be used to clean up the bottom of the hole, especially for blind holes, and aids in chip breaking.
For deep hole drilling and drilling hard materials, variable peck drilling (I, J, K) is effective, requiring chip breaking techniques to prevent chip accumulation.
G73 and G83 Peck Drilling
You’re about to examine the G73 and G83 peck drilling cycles, which offer efficient chip breaking and holemaking capabilities.
You’ll learn how G73 pattern repeating allows for customizable drill patterns, and how the G83 cycle format enables precise control over peck drilling operations.
G73 Pattern Repeating
With the rapid drill cycle, precision is key, and the G73 pattern repeating cycle is no exception.
This cycle cuts in the shape of the profile defined with a subroutine, commonly used when the profile of the part is pre-cut or cast.
The G73 cycle block consists of two lines: G73 U W R; and G73 P Q U W F;, where U defines the depth of cut in the X-axis, W defines the depth of cut in the Z-axis, R specifies the number of roughing passes required, P and Q define the location of the subroutine of the profile, and F specifies the feed rate.
Some key aspects of the G73 cycle include:
- Multiple passes with indexing in both X and Z axes
- Amount of indexing defined by the values added to the first G73 line after each pass
- Used for roughing passes, unlike the G83 peck drilling cycle used for drilling operations
- Often used with long series drills that may be prone to vibration, and for deep hole drilling and drilling hard materials
G83 Cycle Format
The G83 cycle format is a peck drilling operation that enables the drill bit to retract and re-engage the workpiece, allowing for efficient removal of chips and debris.
You’ll use this cycle to drill deep holes or in hard materials, as it prevents drill bit breakage and improves surface finish.
The G83 format consists of a sequence of G and Z addresses, which control the drill bit’s movement.
You’ll specify the drill depth, peck amount, and retraction height using the Z address.
The P address, optional, sets the dwell time at the bottom of the hole.
Peck Drilling Benefits
When drilling deep holes or hard materials, peck drilling cycles become indispensable, as they significantly improve tool life and reduce the risk of tool breakage.
By incorporating G73 and G83 peck drilling cycles into your drilling operations, you can experience several benefits.
These benefits include:
- Efficient chip removal and reduced heat buildup through controlled retraction (R) above the surface or within the hole
- Improved drilling performance with high-pressure coolant to wash away chips and promote lubrication and cooling
- Precise and accurate drilling operations with dwell time (P) to clean up the bottom of the hole, especially for blind holes
- Augmented material removal for deep hole drilling and drilling hard materials with variable peck drilling (I, J, K)
- Intensified material removal for deep hole drilling and drilling hard materials with variable peck drilling (I, J, K)
G-Code Syntax and Parameters
You’ll need to understand the G73 command’s syntax and parameters to effectively utilize the rapid drill cycle.
The G73 command format is G73 X Y R Z H Q E D P F S, with X, Y, R, Z, H, Q, E, D, P, F, and S being parameters. While most parameters are optional, X, Z, and R are required.
Using G73, you’ll define the pattern repeating roughing cycle, where the tool cuts the shape of the profile on each pass, indexing in both X and Z axes.
The cycle block consists of two lines: G73 U W R; and G73 P Q U W F;, where U and W define the depth of cut in the X and Z axes, respectively, and R specifies the number of roughing passes required.
Drill Cycle Examples and Variations
Now that you’ve grasped the G73 command‘s syntax and parameters, let’s examine some practical examples and variations of the rapid drill cycle.
The G73 command is versatile and can be used in various drilling operations.
Here are some examples:
- Use G73 to drill a series of holes along a straight line, specifying the X and Y coordinates for each hole.
- Drill a pattern of holes using G73 with incremental X and Y movements.
- Employ G73 to drill a circular pattern of holes, specifying the center coordinates and radius.
- Combine G73 with other G-codes to create complex drilling operations, such as drilling holes at an angle or with a specific depth.
Related G-Codes and Applications
The G73 rapid drill cycle is often used in conjunction with other G-codes to perform specific machining operations.
You’ll commonly find it paired with G71, G72, and G76 cycles for roughing and finishing operations. For deep hole drilling and hard materials, you might opt for the G83 peck drilling cycle instead.
When working with CNC lathes, you’ll often combine G73 with G00, G01, and G42 to move the tool and turn on tool nose radius compensation.
Additionally, G-codes like G81, G82, and G83 are related to drilling and tapping cycles, and can be used in combination with G73 for specific machining operations.
CNC Codes Similar to G73
|
Code
|
Mode Description
|
|---|---|
| G74 | Peck drilling cycle for CNC lathe |
| G75 | Grooving cycle for internal or external grooves, often using pecking method |
| G76 | Threading cycle for external threading operations |
| G81 | CNC drilling cycle |
| G82 | Standard drilling cycle with dwell at the bottom of the hole |
| G83 | Deep hole peck drilling cycle |
| G84 | Tapping canned cycle |
| G85 | Boring Cycle or Reaming Cycle |
| G86 | Boring cycle; spindle stops at the bottom and rapid retracts out of the hole. |
| G87 | Side Drilling Canned Cycle |
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