This really annoys me

…but I’ll admit it may be my lack of knowledge.

TLDR; This is a long-winded bug report

So I’m engraving a pcb, which turned out nice, but now I’m at the drill stage. I used Fritzing for the design, carbide copper beta for the gcode generation, and carbide motion 4 for the actual fabrication, on my Shapeoko 3.!Arg9f0GH8EvIhZVJZ0sJZEYxPv9_hQ!Arg9f0GH8EvIhZVIx54aO1tnRXN2Ow

How am I supposed to change the bit? What’s annoying is that there is no way in carbide motion to cancel, no way to override z height to allow changing the bit.

Surely this is a basic issue?


Hi @webtop,

The standard process for managing tool changes is here, basically : generate one g-code file per tool.

To automate that, you can then optionnally buy a BitSetter, and CarbideMotion will then automatically stop for tool changes, and re-measure tool length.


I’m talking about a VERY basic setting here in the software. That being a way to cancel that dialog box. I’m not even talking about an override here, just a cancel button. The only way to get out of the state is to hit continue and then hit pause. That’s just bad software design (I’m a 25-year senior software engineer, so I’m not just talking sh*t).

And the response “buy more stuff from C3D” is ridiculous, no offense. All I want to do is say “lift the z-axis so I can change bit”, if it’s off then that’s when I need to look at a better option.
But seriously, $120 for what amount simply to a button in a box is highway robbery. And to not offer an alternative (i.e. a software option, even a manual option) is just plain un-user friendly.

Remember, this was all generated using C3D software…so maybe Carbide Copper should take this into account.

So I hit continue, hit pause, changed to the drill, hit start, and lost a brand new drill bit that I’d just got from C3D today…again at a ridiculous price.

No wonder people are buying alternatives…$120 for a button is shameful, especially after forking out $1500 for a machine.

Truly, one very pissed off customer.

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If you want more freedom in the workflow, you can download a (free) alternative G-code sender like CNCjs. It will let you do what you describe.

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Why can’t CM detect when there ISN’T a Bitsetter in use? At least a friggin’ check box somewhere.

There is a BitSetter option in the settings menu, that you should uncheck if you don’t have one plugged ?

Yes, but there is no other way to change z height without it, other than to create separate files, which truly is not an answer when the software allows the option of having multiple operations in a single file.

And let me just add…I really like the machine, but the software does not compliment it at all.

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I’ve tried that before, but it didn’t seem to change the program pardigm.

You can always run your bit #1 code, rezero and run your bit #2 code. I am really puzzled why all the venom recently about basic CNC operations. I guess people want everything automated so they can put a piece of wood on the machine and out comes a masterpiece.


For anyone that finds this and may be interested:

If you make sure to use the version of Carbide Copper at there is an option to save just the toolpaths at the end, which will create a zip containing an engrave file, a drill file, and a board cutout file as separate files.
However, and this is a big however, during the gcode generation it will ask you for the cutout file to cut the board from the stock, do not confuse this with the “contour” file it produces, otherwise you’ll then end up using a flat endmill to cut out your board but it will then start the engrave process again.

Contour to me means the end operation where you remove the workpiece from the stock, but in Carbide Copper this is the actual PCB etching file. Abuse of a known standard name, but that’s for another forum.

The end result of this 20 minute job that took over an hour was a beautiful PCB which then had a 1/8 endmill dragged through it, a broken drill bit, and a LOT of frustration (which to be fair seems to be the default when using Carbide Motion, so I should have known better).


I don’t want everything automated, I’m happy to do things manually, but when a piece of software doesn’t give you the basic CNC options but calls itself CNC software, it’s kinda sad. In my case, having the current bit 1/4 inch from the workpiece and the software saying “now change to the next tool”…how? I don’t have enough room to even take the last tool out!

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I’m not buying a drill and complaining that it doesn’t hammer in nails…I’m buying a drill and complaining because there’s no way to change the drill bit it came with.

lets say you are given the option to have the z height retract to a suitable position for changing bits…how do you intend to communicate to the machine controller the length of the new bit installed?

The same way as the old timers used to do it: manually. You could match the current retract offset with a shim, or simply measure it, lift the Z, change the tool, lower the Z to the previous offset, tighten the collet and say “Go!”

We learn very early on that stick-out is only what you need, so if I have a 1 inch bit, with a stick-out of 1/2 inch, why would any piece of software retract 1/4 inch from the material and say “Now change the bit”? I’m shy 1/4 inch just to get the old tool out.

There is no room to change it…I couldn’t even get the old bit out, and as there is no way to retract the Z, the software is asking me to defy the laws of physics.

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I understand what you are saying. So a simple increase in the retract height would suffice. The owners/programmers of carbide3d are on this forum and have had threads going asking for feature requests:

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The Copper Beta has an option to output a zip file with each tool in a different file to make tool changes easy. Right now it’s under the poorly-named “Toolpaths Output” button instead of the “GCode Output”.


thanks for the links, will start reading and learning. may i ask you some questions in future if i would have any? thanks again.

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Just a thought but why not just hand edit your Gcode to add a retract at the end of the operation before the M command to change the tool if the Z height is the issue. Can you post your Gcode?

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