Fusion 3D CNC machining/pathing issues

[dilshadsa]

Hello. I am having a few issues with the pathing of my CNC drill in Fusion.

Context:

(I am milling into wood. 3D adaptive clearing -> 2D Contour. Inventables Carvey, 1/8" bit upcut. For a school project, first time doing CNC work. I want to avoid changing to a smoothing ball bit mid operation. I understand that 3D adaptive clearing alone isn't the best option to achieve this shape, but it seems to be the simplest.)

The first of these problems is these circular yellow paths that are created in the milling path as can be seen below. While the smaller ones are little more than eyesores, the larger circles often cut into the stock without any regard for it which has already led to a near-disastrous cut today. I want to get rid of them.

While the problem of some of the larger circles was solved by reducing the offset of the boundary in Geometry, the others remained. I don't want to reduce the offset any further because then some of the faces are not cut by the 3D adaptive clearing due to their steepness. However, I would be fine with just letting the 2D Contour take care of those steeper faces and make my own manual cutting later (if that is the only solution).

The second issue can also be seen in the image above. "Rapid Collision with Stock" occurs many times throughout the operation(s). In most of the cases, the bit either cuts down into a part of the wood that still has a lot of depth, or ends up cutting a part of the wood with the upper portion of the flute (a majority of collisions near the end). I do not know how to fix this problem, though I have tried.

I would appreciate any tips, concerns, or exact problems found from the file I will attach below.

The following picture shows the shape of the piece that I am cutting, and the steep sections mentioned in the first problem.

 

[seth.madore]

First off: The Adaptive toolpath is a Roughing strategy, meant to remove the bulk of material for a finishing toolpath.

How are you holding this part, are you free to cut all the way to the bottom and not have the part fly off to some random part of your workshop? Do you have a vacuum table or some other method of retaining the part to permit 360 degree cutting around the perimeter? 

[seth.madore]

Take a look at this example, adjust to suit your needs/machine limitations.

[dilshadsa]

Hello, the part is contained within the Carvey box (it is a small CNC) and clamps are used in areas where cuts are not being made. This holds down the stock but I do not believe it would hold down the part if it cut all the way down. This is why I was informed to use 2D contour to add tabs which I would remove later, manually.

Thank you for the file, I will take a look at it and see if it solves my problem given my constraints.

[dilshadsa]

I took a look at the file. I understand now that I have not been using the adaptive clearing for its intended use as you said, because there are zero "collisions" in the file.

However, this path is not possible because clamps are needed to keep the stock secure. The yellow circles appear again in this file but I suppose they aren't an issue since the adaptive clearing is being used as intended.

My current plan is to just continue with the file I originally had but on a much slower speed so the "collisions"/yellow circles are not an issue. If there is an alternate machining strategy that would work, please let me know. (Perhaps starting with the 2D contour then creating another path off that result?) Thank you.

The machines we have access to are shown below. The X-Carve would be ideal but it does not have the precision I would be looking for once I create the final design (this is a prototype).