Toolpath for "contour" including a vertically rounded edge

[jludwigC73AM]

I'm cutting a block of foam down to fit a lid of a Pelican case. My current work flow is to measure the radius and use a calculator to figure out my stepdown based on the width of each stepdown being no more than .2" so that I don't leave any material behind with my .25" endmill.

Some Pelican lids include ribbing in the corners or some structural bands running along the width. That makes my method complicated and ugly. Additionally, most Pelican cases are slightly tapered inside, so I have to find the smallest circumference and extrude/inclusion down to get right angles.

I have to assume there's a way I can just tell Fusion to start at a point and circle round and round until it clears everything. I have managed to use the 3D Contour to get those steep tapered sides, but I just can't get the radiused edges. I've attached the model of the case directly from Pelican; STEP files in a zipped folder. You'll have to create a patch and then boundary fill to get the "blank". I've also attached my Fusion file with my contour attempt.

I've watched videos about the contour, scallop, and blend, and I just can't seem to grasp it. My stock is always 20x24" and the thickness is exactly the height of the model every time. My endmill is an Amana 46272-K, for your size reference. I keep the DOC at .75" max, .2" stepover max (Except where I have to take a full width cut of course. The foam is super forgiving, so I can run the thing at 24000 RPM, 6000 mm/min no problem.)

I don't mind if there are cusps left over. It doesn't have to be smooth or pretty, it just has to fit in the lid and I want it to be more straightforward than splitting the model into layers and using multiple extrusions and 2D contours. Thanks!

[etfrench]

1. Create a sketch on the origin.
2. Project the body to the sketch.  Make the projected lines Construction lines.
3. Offset the lines slightly more than the diameter of the cutter.
4. Use the offset lines as the boundary in a parallel toolpath.  Set the

If the ends where the toolpath is parallel to the fillets, create separate toolpaths with the direction 90 degrees to the fillets.  Use a small bounding box to save time.

[jludwigC73AM]

I don't want the endmill wasting time by cutting across the flat top of the model. I just want it to go round and round, creating a stepped curve starting where the curve starts and ending at the bottom of the model. My stock is already exactly the right thickness. That's why I thought the contour was the correct choice. I just couldn't get it to go over the curve. I can only get it to start at the top of the flat side.

[etfrench]

Use a sketch to create the boundaries:

Parallel: It would be best to create four separate toolpaths for this one.

Contour:

[jludwigC73AM]

Can you show me the other tabs on your contour toolpath there? That looks close to what I want, but I can't see what I'm selecting incorrectly. I can still only seem to manage to get it to cut the flat sides. I'm not sure what I'm missing.

I've attached a new file that I've painstakingly chopped up to make my ideal final shape. I don't want to have to make those chopped layers in the future, which is the goal of a single, or maybe two, toolpaths that do all of this for me. My vision is that there is a contour path that follows the radius edge of the model, taking cuts that are no bigger than .2". I don't care about the DOC there, because I know it'll be less than my max of .75". Then, when it reaches where the radius stops and the "sloped" flat side begins, it takes .4" DOC, and I don't care about width there because I know it's less than .25". Notice that the furthest edges of each slice is inside the boundaries of the original radius edge and sloped side. That will ensure that even though my final cut wouldn't be smooth, it would fit inside the lid of the case.

Those widths and depths are largely arbitrary, though the .2" width has been a good max to have with this foam material. I could remake this stepped, "ziggurat" style model for all my Pelican cases, but it's really time consuming. If it's the version that makes the most sense, I'll keep doing that, but like I said, I was hoping a simple contour path would just do it for me.

[etfrench]

You need to create the bounding boxes in a sketch to control where the toolpath will cut.  When the Tool Containment is set to centered, then the bounding boxes need to be offset the radius of the cutter.

File from original case is attached.