Feat Req - Allow negative pocket heights

Feature Request Carbide Create
1

Right now, there is no way to have CC remove material that is above the top surface of the stock when using either of the recommended Z Zero options. You have to use a ‘fake’ Z Zero that is above the material to be removed.

This comes up for two common situations:

  • Removing epoxy overpour
  • Removing the back of inlay plugs.

If we could specify negative pocket heights, then we could use our regular Z Zeros, without having to make specific accommodations for this one toolpath. This in turns reduces the chance of confusion when re-using a project file in the future, since with this feature all toolpaths could use the same Z Zero.

5 Likes
2

What about setting up your desired zero surface as the bed - zero from that - wouldn’t your cut then cut down to that level?

3

If the bed is your zero, then the ‘fiddling’ is changing the stock thickness. You still need to change something to be able to cut above the top-of-stock.

Negative pocket heights work both for top-of-stock and bottom-of-stock Z Zeros, without having to special case this one pocket.

4

Read this several times confused on it all, but I don’t do epoxy work.

I would picture you remove parts from machine for epoxy pour or plug glue up with clamps. Both requires dying or curing time. Not running another job while waiting?

Anyway, then you place parts back on machine, wouldn’t you want to mill to same Z0 set at top of material. Why need to raise up? Are plugs or epoxy so thick it needs multiple passes? What bit are you using surfacing which must cut shallow?

If uncertain of cut depth or want to sneak up to exactly material surface not go deeper, wouldn’t the something to change be raise Z at the machine?

5

Inlay plugs can be very thick. It depends on the material you might have and how much it’s worth trimming down beforehand. I haven’t done many inlays, but 10mm isn’t crazy.

For epoxy, the problem is there is no way to create a pocket that ends at Z zero. You have to have a start height higher than the end height, and the start height can’t be above Z Zero. So the problem isn’t the thickness of the epoxy, it’s that you can’t specify the operation at all - unless you create a ‘fake’ Z Zero that is higher than the real one, then cut downwards from the ‘fake’ Z Zero. So now your project requires 2 different Z Zeros, one of which is needed for only one operation.

Allowing negative pocket heights makes all these problems go away.

6

Okay I think you say fake Z Zero to mean the same as I do by raise Z at the machine. It isn’t so bad to me but understand what you mean now.