What is a Post Processor?
Chris Davala 05.21.2021
The toolpaths from a CAM software do not directly go into your machine tool – there’s an important middle step that enables the whole process. Understanding the value of a post processor is essential to knowing your machine’s limitations and maximizing your capabilities while avoiding costly downtimes. Discover what you need to know about post processors and how the right post processor can make or break your productivity.
What is a Post Processor?
A post processor is software that converts CAM outputs into a specific code that your machine can use. Your post processor acts as the gateway between your CAM system and the machine tool. When you’re programming a part within your CAM system, that code is its own sort of language. A post processor takes that language and converts it to G-code, which then runs on the machine tool. Having a quality post processor is a key part of your manufacturing process, since it helps ensure that it takes what you’ve created with your CAM system and helps make your machine run correctly to create a good part.
The post processor you need depends on the type of machine tool you use, and they vary in complexity. Each post processor requires configuration for the specified OEM machine tool, the individual model of that machine tool, and any specialized features/functionality it contains. From a simple 3-axis mill to more advanced machines that utilize rotary axes where the post has to understand how to manipulate those rotary axes to keep the tool in contact with the part as well as remaining within machine limitations.
When Would I Need to Use a Post Processor?
Any type of machining that requires the use of a CAM software also requires the use of a post processor. When machining parts with complex shapes or limited flat surfaces, using a CAM software with a post processor is always the best option. Manually figuring out where each point you need to enter is located is not realistic for these complex parts – it would take an excessive amount of time for even the most skilled programmers, and there is always room for human error. A well-written post is going to save you time and money and improve the quality of your production.
What Makes a Good Post Processor?
Posting G-code is normally completed with a quick button click within the CAM software, and the magic happens behind the scenes. The key metric to a great post processor is one that does not require any code edits. Tweaking or manipulating the code after posting can cause not only issues with the machining of the part, but also safety concerns due to human errors.
OEMs, like Okuma, work directly with the CAM providers to validate the post processors are outputting good code. The QC and certification processes are rather intense between the CAM provider and Okuma – as quality output for the end user is always a defined goal.
What Happens if There’s a Problem With My Post?
When an issue occurs with machining a part, it is very important to troubleshoot your machine tool as well as the software output of the post processor with your CAM vendor. In more complex situations, a collaborative effort is necessary between the machine tool manufacturer, their distributor, and the CAM software provider to correct the issue.
There’s a level of trust that the post processor will complete the task as intended - however, many shops choose to also simulate the G-code output using another software system, such as Okuma’s 3D Virtual Monitoring, before moving to the machine tool itself. If an error should occur, this allows for a correction at the CAM level – ultimately saving time, material cost, and potential machine collisions.