Recessed model not leaving a smooth transition to surface

[SimplyDifferent]

Still a newbie to this addictive habit here. Got the orientation correct and ran my first test piece. I used the free lily pattern in the "B" or dished model. As I look at other folks projects, I see the dish has a smooth transition to the surface. Mine came out with a lip or ledge all the way around the recessed oval pattern. How do they get the smooth transition?

Thanks,
Dan

[tonydude919]

Dan,

Can you post a pic of it?

Tony

[tmerrill]

Hi Dan,

I am going to assume you are using 3D Machinist like your other recent posts. If not, please let us know which program you are using.

Here are a couple of quick things to verify and try:

In Step 2, select the top of the material as your Z-zero point and this is where you will set your machine's Z-zero point to zero. This means when the tip of your bit is just touching the top of the material, your Z height is reading 0.0. Your material should be smooth on top and have the top and bottom sides parallel to each other (equal material thickness everywhere).

Also in Step 2, be sure the Gap Above Material is selected and set to 0.0. If this was set to a value larger than zero, that would result in 'pushing' the model down into the material by that amount which would create a lip.

The toolpath previews are very accurate and if you are not seeing the lip in the preview, then it is likely the first issue above. But if you are seeing the lip in the preview, then the second reason could be the cause.

Tim

[SimplyDifferent]

Tony,

Thanks for the replies. I had the gap above material set at 0.10 because Machinist 3D gave me a warning about using 0.0. This makes perfect sense as the lip is just under 1/8" inch, so the 0.100" makes it right there.

This forum is the best place to get help with CNC routing!!!