SolidCAM’s official forum has a section where users share custom posts (for free). However, these are user-contributed and often not fully tested.
Here is the interesting alternative you haven't tried: SolidCAM’s "Post Debugger" tool.
Inside your legit SolidCAM install (even the educational version), there is a utility called GPP Tool. It lets you build a post from a wizard by answering questions: solidcam post processor download free
It takes 20 minutes. It produces a custom, error-free post. And it is free because you already own the software.
In simple terms, a post processor is a translator. SolidCAM creates toolpath data (CLDATA), but your CNC machine (Fanuc, Siemens, Haas, Mazak, Heidenhain, etc.) needs specific G-code syntax to run. SolidCAM’s official forum has a section where users
A post processor takes the generic data from SolidCAM and formats it into a text file your machine controller can understand. If the translation is wrong, the machine could crash.
Editing a post is iterative. Free posts often need 5-10 test cycles before they are production-ready. It takes 20 minutes
If you have programming skills, you can write a basic post from scratch using SolidCAM’s GPP (Generic Post Processor) Tool.
SolidCAM support will refuse to help you if you use an unauthorized or modified post processor. They will point to the license agreement: “End user shall not reverse engineer, decompile, or modify post processors without written consent.”