Engraving toolpath start depth

[Old_Rustic]

Folks,
The new VCarve Pro update to 9.512 seems to disallow negative start depths.

Problem:

Engraving small letters using a 30 deg engraving bit in MDF. With a flat depth 0f 0.125" and "Start Depth" of 0.00" many of the letters are missing sections where the text is faint. The solution in earlier versions was to set a negative Start Depth, i.e. -0.010" or -0.020". Doing this in 9.512 in the edit toolpath screen allows the entry of a negative number, calculates successfully, but still shows missing segments in the preview. Going back to the toolpath edit shows whatever negative Start Depth was entered is now a POSITIVE value. Reproducible in several projects.

I really do not like having to set Z-Zero to below the material surface to fix the software issue.

Mike

[ger21]

Send an email to vectric support.

[mtylerfl]

Hi Mike,

Could you post a file that is showing the problem you are having?

Are you setting Z-Zero to the material surface? The way I’m understanding your description isn’t making sense to me. If some sections of letters are missing and/or faint, then it seems to me you DO need to have a positive Start Depth to compensate for vectors that are so small and close together that the Bit can barely fit in the internal space between the vectors. (A positive start Depth forces the Bit to go deeper into the material surface by whatever amount you specify. A negative Start Depth would Force the Bit to start above the material surface and make the “problem” worse!)

Maybe a file that we can look at will add some clarity. I’m also missing the reasoning why you would need or want a negative Start Depth anyway. Again, maybe a file post could explain?

[LittleGreyMan]

Mike,

I agree with Michael. It doesn't sound logical.

I think you also had a positive offset with the previous versions and the minus sign was simply remaining, which in this case was a bug.

You can verify this simply. With the old version, calculate a toolpath without offset. In the toolpath list, hover the toolpath with the mouse and note the depth. Edit your toolpath and set a 0.01" positive offset. Calculate and note the new depth. Repeat with a -0.01" offset. I'd bet that you get the same increased depth of 0.01" with the negative and positive values.

IIRC, the software never accepted negative values and there is still an UI glitch that allows entering them without an error message. Switching them to positive without issuing a warning for the user is not a good choice IMHO.

[Adrian]

Which earlier version do you think behaved this way? I've gone back to V7 of VCarve and it behaves the same way as the current versions. A negative value can be entered but it will be converted to positive once the toolpath has been calculated, closed and edited. As Didier says not the ideal way of doing things but it's the way it's worked for quite a while now.

[Tailmaker]

Agree with Adrian. Has been like that forever. I complained about that sign swap a few times but the feedback was usually "allowing negative start depth will confuse people". I still would appreciate it but I have enough workaround options.

[mzungumike]

Ok, here is another question about the Quick Engrave Toolpath and Start depth. I am cutting out a wooden tray, that will be 0.5" deep. I want to "Quick Engrave" in the bottom of the tray. How do I set the start depth for the Quick Engrave tool path. I cannot v carve, because some of the vectors are not "closed" is it possible?

Material Thickness: 0.75"
Cutting out a pocket: 0.5" deep with "bowl/tray bit"
Want to engrave in the bottom of that created pocket.

Thanks

[Tex_Lawrence]

You are setting a "depth". That means below the surface by definition. So, a direction of "negative" is already implied in the definition of Start Depth.

[Adrian]

Ok, here is another question about the Quick Engrave Toolpath and Start depth. I am cutting out a wooden tray, that will be 0.5" deep. I want to "Quick Engrave" in the bottom of the tray. How do I set the start depth for the Quick Engrave tool path. I cannot v carve, because some of the vectors are not "closed" is it possible?

Material Thickness: 0.75"
Cutting out a pocket: 0.5" deep with "bowl/tray bit"
Want to engrave in the bottom of that created pocket.

Thanks

If you're engraving lines (not using the quick engrave fill) with a normal bit then you could use a profile toolpath set to be "On" the vector and set the start depth to 0.5".

If that's not an option and it has to be the quick engrave toolpath the only way I can think of is to zero the machine to the bottom of the pocket and cut from there.

[adze_cnc]

If some of the vectors are open that says to me that you are going to be using the “outline” option rather than the “fill” option of the Quick Engrave toolpath.

If that”s so then why bother using the “Quick Engrave” toolpath at all? Just use the Profile toolpath ‘on the line’.