GrblGru: Free CAM program with 3D simulation for mills and lathes

This is my first post here. A good friend recommended me to present my little program “GrblGru” here.

GrblGru is a CAM program with 3D simulation for milling machines and lathes. For example, you can virtually view a ShapeOko or an X-Carve machine while processing your GCode and check if there are any collisions. The special thing about it is that you can also integrate a 3D model of your own DIY machine into the program.
Furthermore the program can be used like the Universal GCode sender to send GCode to Arduino Uno with Grbl, to TinyG or to Arduino Due with g2core.

To give you an idea from GrblGru, I recommend you my videos on youtube or a look at Shapeoko Forum where the program was ‘born’.

ShapeOko forum:

The program and some information about it can be downloaded for free from my website at

In the attachment you can find my last video that I made about the new lathe functions.

Have fun with GrblGru

I am unsure whether this category is correct for my program and please the administrator to position my post accordingly.


Thanks! That looks really cool! I just read the English manual. (Yes, good choice of category, too!)

Has anyone tried running it under Mono on Linux? Or does it depend on interfaces that aren’t implemented in Mono?

Is it open source or proprietary? I noticed the manual made reference to grbl being open source, but didn’t see it say what the license GrblGru is provided under or whether source is available. Maybe I just read too quickly. :slight_smile:

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Thanks for the nice welcome. :slight_smile:
I’m not aware that anyone is running the program on Linux. But it would be great if someone could try it. Unfortunately I don’t understand enough about Linux
So far GrblGru is not an Open Source project. I like to work with CNC machines, like programming and make the program available for free.
In return I hope to get suggestions and ideas to improve GrblGru further.

you can see what I’ve done so far.

I downloaded 3.73.3 to try whether it would work on Mono on Linux, but after unzipping to get the installer executable, that executable wasn’t a self-extracting CAB file, so I gave up on getting the actual executable out to try it under mono on Linux. (Mono is the C# implementation that Microsoft now maintains for Linux; after purchasing the company that made it in the first place.)

Since I don’t run windows, I think I’ll stop there for now, even though GrblGru looks interesting.

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Have you tried running it under WINE?

No. Don’t have it installed on this system.

I was able to install the program on Ubuntu using wine but no luck actually running the program. Will have to see if I can tweak wine to run it.

Or, now that it’s installed, maybe you can run it with mono?

@GrblGru Is this based on a fork of FreeCAD? (It looks like FreeCAD)

Thank you for your interest. :slight_smile:
No, GrblGru is self-made and is not based on any other program.
The program is created with C#. The framework 4.0 is integrated. GrblGru runs under Windows from Windows XP upwards.
For the graphics I only used the elementary function of OpenGL. (Points, Lines, Triangles etc.) which is a normal part of C#. All normal stuff, no special features.

Release notes V3.38

In my new program version V3.38 I once again worked with the function G38.2 for milling.
This good and at the same time easy to use function makes it possible to scan uneven surfaces, e.g. to engrave them afterwards.
The same applies to the production of PCBs, where any unevenness must be compensated.
GrblGru also offers the possibility to scan STL objects in simulation mode.

Download, as usual from my website at
Here you can also find a short video about the last changes.

Have fun with GrblGru

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Release notes V3.39

the topic of measuring and probing with the help of the G38.2 function hasn’t quite let go of me yet. It’s fascinating what you can do with a 10 Euro Arduino and the GRBL program.

A friend of mine provided me with an old discarded probe, with which I could demonstrate the handling in the attached video. Since I unfortunately have a tendency to use temporary solutions, the mounting of the probe is rather suboptimal. :slight_smile:
But my main goal was to be able to show the actual measuring.

In the new version, I have also extended the measurement spectrum so that you can now measure in all directions. This makes it possible to measure angles, find centers and much more.

Have fun with GrblGru

I would have liked to give here a link on my youtube video. But it is not allowed to me. What am I doing wrong ? Can someone please explain to me how to do this ?

Thanks for mentioning it, I fixed it for you.

(It’s a Discourse auto-spam-prevention feature; by default new users have to interact with the site for a while before they are allowed various things. I just told the system you are trusted.)


Thanks for your help. Now it works. :slight_smile:
Is that perhaps the same reason why my last post (Apr 27) was flagged and hidden?

Here is the video

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Yes that was most likely the reason.

I am doing something wrong. Windows 7, if I even unpack the exe file from the Zip file, Windows Security Essentials says “Detected threats are being cleaned” and the folder is empty.

I downloaded 3.39.0 from the GrblGru website. I’m very interested in drag knife support.

You need to turn off your antivirus so it will not delete the files. it is very safe and secure to use this program. I’ve been using it for years.

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This is apparently how you tell Microsoft about these things; either they take it off their list or find that it’s actually been infected by a virus.

Since I’m on Linux, I don’t have experience actually using that site… :slight_smile:

@GrblGru note there is a way to submit the files as a software developer and you can say you believe it was incorrectly identified. I think that requires an MSDN account but since you are writing windows-only software I suspect you’ve already done that.

@Steven_Greenfield you can submit the file as a home user without creating an account, or create an account if necessary in order to follow up.

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