What is Post Processor in CNC Machining?

Computer numerical control (CNC) manufacturing can only be actualized with the help of a post processor. We will look at how post processor fits in CNC machining in this article.

What is a Post Processor?

In CNC technology, production process is achieved with the aid of computer aided design/manufacturing (CAD)/(CAM). CAM software simulates the tool pattern as imported from CAD and a post processor converts this data into instructions for CNC controls.

It does this in form of geometric codes (G-codes) that is specific to the machine.

When to use Post Processor in CNC Machining

A post processor is also known as a “Post” is short. It is an interconnection that communicates CAM data output to a CNC machine controls. It ensures that the CNC machine in use understands the commands from CAM and generate the accurate toolpath.

Consequently, its role cannot be ignored in any CNC machining. Its role is to guarantee part accuracy, equipment and user safety.

It is important to ensure that the post processor software applied is compatible to the CAM program of the machine used.

Features of a Good Post Processor

CNC Milling Machine

CNC Milling Machine

A good post processor should bear the following characteristics:

· Compatibility

A good post processor fusion 360 should be harmoniously translate CAM data to machine controls. Compatibility of this important links permits smooth flow of data from CAD/CAM to machine controls producing accurate part geometries.

Additionally, it helps reduces errors, inaccuracies and any other compatibility related issues.

· Complete Translation

A good post processor should be able to accurately communicate CMA data output into a G-code without any code adjustments. This eliminates the chances of error, inaccuracies and even machine damage that may arise from code manipulation.

· Ease of Use

A good post processor generator should be simple and easy to operate. Some post processor may require user training before use but that should only be for proper functionality and troubleshooting purposes.

· Shelf Life

Typical post process shelf life is two years before it can be faced out or upgraded. A good post processor should perform optimally for at least two before it fails or demand for upgrade. This offers users their money’s worth and trust in your product.

· Additional Features

A good processor does not stop at communicating toolpath and processing features, etc. It is also able to indicate when cycles are incomplete between tool changes and correct where necessary. It should also perform system upgrade and communicate failure or errors accurately.

How Post Processor Works

Post machining processor in CNC

Post Machining Processor in CNC

A post process functions to translate data from CAM system into G-codes; an information that CNC controls can interpret. It achieves this be ensuring that the G-code generated from that communication is unique to that CNC system.

The following take place in a post processor phase.

Step 1: A CAD in three-dimensional format is taken into CAM system

Step 2: The geometry design processing is then simulated in CAM system to determine; toolpath, feeds, operation tools, time, etc.

Step 3: The post processor software thereafter translates the data from CAM system into G-codes specific for the CNC machine. The translated information acts as instruction to the CNC machine controls leading to processing output.

It is a complete information that contains; optimized toolpaths, feed rates, tools, mode, other functions, etc.

Step 4: Finally, the geometric codes is then fed into the machine for production process to commence.

Recommended Languages for Post Processor in CNC Machining

Post processor used in CNC machining can be written in any programming language. Each language has its own advantage and therefore the choice depends on the manufacturer’s expertise and the goal to achieve.

Some of the languages recommended are:

  • JavaScript: A famous quick prototyping language that is easy to create and modify.
  • C++: Commonly used in post processor due to its flexibility and speedy output.
  • Python: Just like JavaScript, this programming language is suitable for post processor creation.
  • Proprietary Scripting Language: Some manufacturers and CAM developers prefer to use this programming language for their post processors. Well, it can be developed specifically for particular vendor or for external consumption too.

Importance of Post Processor in CNC Machining Process

The importance of a post processor in a computer numerical control machining cannot be overstated given its critical role. The machine controls can only interpret correct toolpath once they receive correct G-codes from CAM software.

Failure of this step can lead to unsatisfactory part production, equipment failure and user risk.

How to Choose Best CNC Post Processor Software

Choosing the best post processor software is crucial for any optimal function of a CAM system. Therefore, careful evaluation of below factors is handy when selecting the best “post” software:

1. Compatibility

The first task is to find out if your CNC machine configurations match with the “post” software you are about to select. Having a software that matches your CNC system is a crucial ingredient for machining performance.

2. Customization

There are open and closed post processor software available. Open post processor allow modification of its software architecture to suit a certain machine configuration, closed system does not permit any modification.

In summary, understanding your CNC machining purpose plays a significant role in selecting the best post processor.

Furthermore, it is important take note of additional costs that may arise with future customization or buying a new software altogether.

3. Functionality

How best does a post processor software work? This can be answered through performing a test on the software before purchase.

During software testing factors like seamless performance, machine controls instruction and performance, toolpath optimization, and any other information should be evaluated.

The best post processor software is one that meets your needs.

4. Quality

Post processor software is what makes accurate part geometry possible therefore, you should source your software from trusted vendors. Reputable vendors can be vetted through checking user reviews from their websites, checking for quality standardization certifications for their products.

Another way of getting the best post processor software is from recommendation from previous users.

5. User Support

User manuals, demo videos and user training are some of the ways though which a vendor can ensure proper software functioning. Ensure you settle for a software vendor that can readily offer system support.

6. Maintenance

Ease of use, troubleshooting and maintenance are some of the things to look out for during the software sourcing process. A reputable software vendor should be able deploy any latest software updates to avoid system malfunction due to out-of-date.

Cost of Post Processor for CNC Machine

A post processor cost a significant amount given its role in CNC machining. Its price ranges between USD 2500 to USD 10,000 depending on equipment, programming language, functionality, brand and size.

General post processor cost less compared to customized post processor. While open “post” seems cheaper than customized option, a customized “post” processor is seen to be more secure.

CAM software providers have readily available open post processor that can be configured for use in any CNC machine. This type of post processor cost much less than customized post processor.

Some CNC manufacturers offer their post processor free of charge but specific to their machine brand. Such post processor cannot function in any other CNC machine because of their tailor-made specifications.

Another way of cost cutting is by adjusting the post processor settings to fit a specific machine. This modification can be done cheaply by a CAM software expert or by a knowledgeable in-house software engineer.

Function of Post Processor Editor

A post processor editor permits tweaking of code configurations unique to your “post” with the aid of a graphical user interface.

This plugin allows you to tailor make post processor to match specific CNC machine configurations.

You can achieve this through the following steps:

  1. Download and install a post process editor plugin from a reputable website.
  2. Go to Program and click on “Post Processor Editor”.
  3. Identify and choose “OK” on the post processor you want to modify.
  4. A new window will pop up with modifiable variables; proceed to adjust accordingly.
  5. Click to “Save Post Processor As (insert suitable name)” and save it.

While performing post processor editing, do not replace the original post processor with the customized edition. Instead, save the newly created customized version with your preferred name to enable return to default “post” when the editor is uninstalled.

If you are having any problem with your CNC machine or coding process, TSINFA team is always here to help – contact us now.

More Resources:

CNC Machine Types – Source: TSINFA

Computer Numerical Control – Source: WIKIPEDIA

G-codes in CNC – Source: G-CODE TUTOR