How to cut finishing path 1mm deeper than the model

[martinwh99]

Hello

I want to do 2 finishing paths the first one should be 1 mm deeper than the work piece and the second one should be exact. How can this be done?
Is it possible to do it the following way:

first i do one with 5mm depth of model below surface and the second one with 4mm depth of model below surface. Will this work? The only problem is see here is the starting point should be at same height for both. But my top surface is not flat. When i enlarge the material size with machine margins around model with 10mm will this extra stay as it is, or will this be milled corresponding to the rest of the block?

regards
Martin

[dhellew2]

I'm trying to figure out what you are trying to do but cannot get the picture in my head. Could you post the file or a picture/sketch of what you are trying to do?
Dale

[Rcnewcomb]

I want to do 2 finishing paths the first one should be 1 mm deeper than the work piece and the second one should be exact

The second one won't cut anything because the material was already removed by the first one

[ger21]

I want to do 2 finishing paths the first one should be 1 mm deeper than the work piece and the second one should be exact

The second one won't cut anything because the material was already removed by the first one

That's the way I read it too.

[martinwh99]

I'm trying to figure out what you are trying to do but cannot get the picture in my head. Could you post the file or a picture/sketch of what you are trying to do?

I want to mill a mold for an elevator of an rc plane. I want to mill the first time 1mm deeper than the model. Then i spread epoxy (about 2 to 3 mm) in the form and mill it a second time with an other nc file (1mm higher). So i think i have to use 2 nc files one cuts 5mm from above the second one 4mm from above. The question is will this work? And because the material is mdf, i need a 1mm epoxy skin in the mold.

When i enlarge the material size with machine margins around model with 10mm will this extra stay as it is

The question for me is will this extra size be milled or not. If it stays as is (i need that for tool change) than is think this could work.

[ger21]

Just use your finished program and set you Z zero 1mm lower for your "rough" pass.

[martinwh99]

Just use your finished program and set you Z zero 1mm lower for your "rough" pass.

The only possibility is see to manage Z is the 'Depth of Model below Surface' option in 'Material Size and Margins' tab. do you mean this one?

[Ms Wolffie]

Can't you just raise your bit 1 mm above XYZ0, let that be your new XYZ0 and cut it again?
That would let Z0 =Z-1

[ger21]

Just use your finished program and set you Z zero 1mm lower for your "rough" pass.

The only possibility is see to manage Z is the 'Depth of Model below Surface' option in 'Material Size and Margins' tab. do you mean this one?

No.
What control software are you using?

After setting z zero, change the Z value to 1.
Then, when you cut, it will be 1mm lower.
In Mach3, after zeroing the axis, you can move to Z zero, and just type 1 in the Z axis DRO. This will give you you're 1mm deeper cut.

[martinwh99]

What control software are you using?

I'm using LinuxCNC

[larrybadgett]

In order to leave a skin or layer you would have to have two models at different scale sizes and calculate the tool path for each. If you don't re-scale the model the vertical edges will cut at the same in both tool paths. Only the Z depth would change by just raising or lower the cut height.

[Ms Wolffie]

I never even thought about that.
Very clever Larry

[ger21]

If you look at his screenshot, there aren't really any vertical edges, so just changing Z zero should work fine for him.

[larrybadgett]

If you look at his screenshot, there aren't really any vertical edges, so just changing Z zero should work fine for him.

I wonder what is causing those shadows around the edges