[MitchB]

In the help for the drill tool, it says that break through is "How much to go below the total drill depth". The implementation appears to use this number as the amount of material to leave above the bottom level. A negative number doesn't seem to work any differently.

[svenakela]

No, that's skin cut.
Break through is the distance to pass the bottom level. Set it to 3 and it will go 3 units (mm/inch) further.

The drill dialog is one big mess of options because people can't think of drilling and do a simple math at the same time.

[MitchB]

I understand what break through is supposed to do. It doesn't do it. Attached is the drill dialog I used to produce the drill path shown. The stock is 0.5" tall. The drill stops at the break through height ABOVE the bottom of the stock - not BELOW as I'd expect and as you described.

[JOM]

There are a couple of options for drilling. The default is to automatically measure the start level from the z-level of the curve. The depth is set relative to the start level. If you set the depth to minus in your case, the break through will then be correct.
Attachment 234282
Attachment 234284

/Joakim

[MitchB]

Thanks. That makes sense and works. Ideally wouldn't the result of using a positive drill depth with a start level of "from curve" result in a nonsensical tool path or an error instead of something that looks sort of OK?

[Dan B]

Drilling in madCAM is on the "to-do" list for an overhaul.

[svenakela]

Too many individuals doing requests without getting the dialog in the first place combined with a too kind product owner gives the drilling dialog as a result.