I Recently came across a post which got locked because some kind of war started. People were trashing each other, throwing things at one another tossing tables and smashing chairs across everyones back but in the light of the fallout which looked like something of an aftermath of a RS-28 SARMAT ICBM, some thing good came out of that thread. Colin GilChrist (Which I nicknamed Mill-Christ due to his eapprentice lessons because this guy really knows his stuff on a level which I have never seen before) mentioned how to create new toolpath groups and subgroups and me being new to Mastercam I knew how to do this and understood the purpose of this but Colin showed a way that brought it to a whole new level. I am assuming that most people know this already but he showed the picture below. What struck me in this picture was the subgroups for specific operations.....ie; roughing, drilling, pocketing and so-on. I never thought to use toolpath groups like this before. I only used them to separate different operations. So in it;s simplest form.... the next time I'm drilling a series of holes I will create a group called Centre Drilling another group called drilling, and another group called tapping. The reason why this is recommended is that lets say I need to adjust the parameters for centre drilling I can find them easily as they are in their own group. Because of Colin's post my Mastercam files will never look the same again. Thanks Colin. I know most of you are saying..."well what did you thing the TOOLPATH group was for?? DUH!

What Post Processors do you already have for V9.1? Look in your Post Folder: Install\mill\posts (Install should be something like "mcam9", or something like that.) Jeff's comment about GitHub, refers to a website which hosts "online open-source software code". He looked on Github to see if there were resources available for your controller, and saw that the G-codes for the GRBL are very similar to the Fanuc control. So, the first step is to search through your Mastercam installation for a file called 'MPFan.pst'. This is the standard "mill Post for a Fanuc 3 or 4 Axis". Once you locate MPFAN.PST, you should make two separate backups. Copy/Paste and rename, and also make a separate backup, with a different File Extension. (Make "mpfan_backup.pst" and "mpfan.bak) This is for safety, so if you mess up the logic, you have a way to recover. The "Post" is just a text file, with code written in the "MP Post Language", which is a scripting language. A bit like a cross between VBScript, a Batch File (.bat), and Standard C. The Post contains instructions, which tell MP.DLL, how to process your NCI (Toolpath data), and turn it into NC Code. Now, create a sample Toolpath in 9.1, and Post it with the Post. Once you have NC Output happening, figure out what needs to be changed for your machine, and we can help you do that.

I don't go back to 9.1 but if it has a generic fanuc post it will work with very minor tweaks for GRBL. In fact, I imagine the generic fanuc would straight run with no edits.

The GitHub makes it seem like a Fanuc post with a few tweaks would do the trick, do you have a Fanuc post you could try? List of Supported G-Codes in Grbl v0.9 Master: - Non-Modal Commands: G4, G10L2, G10L20, G28, G30, G28.1, G30.1, G53, G92, G92.1 - Motion Modes: G0, G1, G2, G3, G38.2, G38.3, G38.4, G38.5, G80 - Feed Rate Modes: G93, G94 - Unit Modes: G20, G21 - Distance Modes: G90, G91 - Arc IJK Distance Modes: G91.1 - Plane Select Modes: G17, G18, G19 - Tool Length Offset Modes: G43.1, G49 - Cutter Compensation Modes: G40 - Coordinate System Modes: G54, G55, G56, G57, G58, G59 - Control Modes: G61 - Program Flow: M0, M1, M2, M30* - Coolant Control: M7*, M8, M9 - Spindle Control: M3, M4, M5 - Valid Non-Command Words: F, I, J, K, L, N, P, R, S, T, X, Y, Z

Machine Definition then Control Definition then Operations manager in defaults then Pick Material you want and now that will be the default material. You can do this for each machine you have.