Bas Relief depth

[kenagyd]

The finishing passes are cutting more deeply than intended, and I'm puzzled as to the proper settings.
Part of the project went properly:
The project is a bas relief, with a Z (height) of 0.24". The stock is 3/4" thick wood. I began with a 3/4" bowl bit to remove stock around the 3D model using a "pocket" between the model perimeter and a vector that projects around the stock (but leaves clamping pads at the edges for later removal). I used a 1/2" end mill for rough shaping.
Then things went awry
The finishing passes are a 1/4" Ball Nose and 1/16" Tapered Ball Nose. These cut as deeply as 0.51" into the perimeter.

I suspect my ignorance about setting depths is the problem, but several re-attempts made it no better. I've attached screen shots that might show my programming error and a preview image that shows the problem with the appearance.

[sharkcutup]

The .51 is correct with your settings.

Model Thickness -- .49"
Material Above Model -- .020"

Total Depth of Cut/Carve ------------------------ .51"

When you are using the Modeling (3D)Toolpaths you are at the mercy of the models depth and location within the material.

Sharkcutup

[dealguy11]

You might consider adding a zero plane. This will provide more graceful cutting at the edges of the model and prevent it from "falling off the edges" of the component where there are slight mismatches between the component and bounding vector. I'm pretty sure that's what's happening.

[kenagyd]

I'm sure you're right. I saw another post in which you discussed "adding a zero plane" but I think I need an even more basic explanation. Is there a tutorial you recommend? Frankly, I don't understand the series of "U-shaped" icons (white and yellow, upside down and right-side up). Nor do I understand what "Baking" is (at least not in this context).

[JoeBlow]

You have a base height of .25 and model height of .24 giving you a total model thickness of .49. Change your base height to 0 and then your finishing toolpath will cut a total of .26 (.24model height + .02 for model depth in your material setup)

[martin54]

As others have said the file is cutting exactly as it should with your settings, what was your reason for adding the base height ? Adding base height is basically sticking a lump of material under the model increasing the overall height of the model

Don't know if this will help at all, haven't watched it myself but Mark's tutorials get a lot of recommendations

[kenagyd]

"what was your reason for adding the base height ?"

I didn't know I did that...the setting seemed to appear spontaneously, but maybe it exists somewhere in the (purchased) 3D model???

When I learned that, I re-set the model height to 0.24 and set the height above the model to 0.02. Then I made my "Bowl Bit" depth go to 0.26" and it looked much better.