[oldcrowe]

So... hello all- oldcrowe here from Oregon Coast!!
I have been teaching myself CNC routing/Mach3... and having a ball!
But today I downloaded a sample file, and something in the gcode doesn't make sense to me.
I have attached several pages of the code...
In the gcode, the author has the tool (Z axis) plunging down to 0.000! Please see the attached doc and see the highlighted Z position code.
I ran the code on Mach3, and the tool went down to 0.0000 and worked it's little heart out, but was only touching the work...(Duh...)
So- my question: What am I missing? Is this gcode correct? If so. I really need more schoolin'!:frown:
I copied the code into a text editor, found all the Z0.000 and turned them into Z-0.0500 and had the expected results of actually seeing the bit do some work! But if the gcode is correct, then I'm really missing something!
Thanks so much for your help-
Oldcrowe

 

[Semipro]

Hello and welcome to the router forum Oldcrowe
Must been a tough day the forum went to bed early
I know very little about your problem. But sound like you zero out your bit to the top of the material but never told the software the depth of cut into the wood you wanted

 

[difalkner]

Welcome to the forum! Add your first name to your profile to clear the N/a in the side panel and so we'll know what to call you. Add your location to your profile, as well.

We do like photos so show us your shop, tools, projects, etc. whenever you're ready. What sort of woodworking are you planning or doing with this CNC?

Without looking at your G-code file my first instinct is that you need to zero off the spoilboard, not the top of the work piece. Go back and change all the Z-0.050 to Z0.000 like it was in the beginning.

David

 

[JFPNCM]

@oldcrowe

I'm not familiar with CNC but always open to meeting another woodworker here in the PNW. I claim the Boring area as home.

 

[oldcrowe]

Thanks, David!

Thanks, David, for the reply...

Without looking at your G-code file my first instinct is that you need to zero off the spoilboard, not the top of the work piece. Go back and change all the Z-0.050 to Z0.000 like it was in the beginning.

David

So- if I did that, the bit would cut clear through the work- 3/4 MDF- all the way down to the spoilboard... The model I am trying to make is a 67 Mustang with some script above it with the "Ford Mustangs" galloping in the background... it wouldn't work to cut it entirely through- it needs to be relief work...

I'll send a pic as soon as I qualify- Must have a certain number of posts before they let me play with that gun!!

Thanks again for your help!

 

[oldcrowe]

I've lived in Florence for nearly 45 years!

 

[oldcrowe]

But sound like you zero out your bit to the top of the material but never told the software the depth of cut into the wood you wanted

Exactly! So when I modified the script, I was able to see the desired results. So my question is: was this a mistake from the original author? If I zeroed the Z at the spoilboard, I would have cut clear through the stock!

 

[ger21]

So my question is: was this a mistake from the original author?

It's really impossible to know what his intent was. It could be just the way that he likes to work.

If you wanted to cut 0.05" deep, you could jog the tool down to the surface, and type .05 in the Z axis DRO. Then, when you run the program, it will cut .05" deep.

 

[old55]

Welcome to the forum.

 

[oldcrowe]

Welcome to the forum.

Thanks!!

 

[HDVideo]

If all your Z instructions in the Gcode file are in the positive direction, then the code was most likely referencing the spoilboard as Z zero. If there are Z moves in a negative direction, then some other point above the spoilboard was used as a reference.

When trying to run Gcode that was not generated specifically for your machine, there are often problems and even the possibility of damage to your machine. Reference points for X,Y and Z, speeds & feeds, tooling, material used, material thickness, machine configuration and machine rigidity are all factors that go into the code generation.

Ed

(Edit) - After taking a look at the file you provided, there is no 3D work going on there. It looks like contour (profile) cuts with the spoilboard as reference.

 

[oldcrowe]

Thanks for the reply!!

(Edit) - After taking a look at the file you provided, there is no 3D work going on there. It looks like contour (profile) cuts with the spoilboard as reference.

Thanks so much for your explanation. I appreciate you taking the time to look at the file and help me make sense of what was happening! That's why I wasn't seeing what I was expecting to see...

At this point, the learning curve is fairly vertical...