OK, I have a lot to talk about.
I have a project that is a fan shroud/support that hangs off the back of an electric motor. Basically it is a cone with an 83mm ID on one end, a 5.8" ID on the other end, 6" between ends, and a .5" wall thickness.
I have a CNC router, but the Z travel is only 2", so the idea was to build it out of stacked & glued plywood rather than hogging it out of a single chunk of wood.
The model is a loft between two sketches, so it is a true cone. The small end is on the bottom (Z0) and the big end on the top (Z+)
Installed Slicer and ran it. It brought in the model with no issues. The orientation of the slices was initially on the Y axis instead of the Z, but that was reasonably easy to figure out and change.
So the first disappointment was that the slices cannot internally track the profile of the object within the slice. By which I mean, slices of a cone along the Z axis are "rings" (which Slicer did right) but the cross-sections (X or Y) are trapezoids. Slicer can't do that - it's cross-sections are always rectangles. Or to put it another way, to properly track the profile of the cone, the diameter of the ring must be smaller at the Z0 position than at the Z+ position.
I can more closely approximate the profile of the cone by making the construction material thinner... but very quickly the cut list gets ridiculous. (Although it is a brilliant illustration of how calculus works!).
In my application, I can live with stair-steps on the outside profile, but the inside profile needs to be smooth. And that's OK, because I cannot cut the outside profile without flipping the part over anyway. So now the plan is to import the slices back into Fusion, and then add a chamfer to the inside profile at the proper angle.
NOW - here is my expectation: I expected Slicer to create native Fusion 360 parts that represented the cuts. So if my chosen slices needed 3 sheets of plywood, Slicer would create 3 parts, where each part would be the number of slices that fit in a chunk of plywood of my chosen size - super easy to do CAM from there.
Nope. No way to get part back into Fusion360 natively.
OK... so let's export as .STL. Well that generated a series of STL files, 1 per slice, but did not preserve the relationship of each slice to the sheet of plywood, so I would have to re-do that layout by hand. And on top of that, each STL wasn't smooth curves, but was a segmented polygon. Bleah. That doesn't work.
OK... so export the cut drawings as .DXF files, and extrude them. Hm. For some reason the DXFs also don't do smooth curves, so when you extrude it and try and select a profile in CAM, you have to select a series of little segments. Bleah.
OK, import the .DXF, then create a new Fusion360 sketch using the DXF as reference. In my case, that isn't super onerous because the slices are just rings, so a 3-pont circle takes a fraction of a second to draw. Extrude that sketch, and now I have proper native 360 objects for each slice, arranged properly to fit in the size of the stock I want. Drop a chamfer on the inside of each ring, and Bob's yer uncle.
That goes to CAD. 3 toolpaths: a 2D profile that cuts out the inside of each ring, a 3D profile for a ball-end mill to cut the chamfer, and a 2D profile to cut out the outside.
That goes to the router, and it works. Glued up, I have a section of a cone, stair-stepped on the outside profile, but smooth on the inside profile. Huzzah!
...until I place it against the fan, and discover that the diameter is slightly too big. What? Cross-reference against the model, and the model is fine. Check the DXF... and the DXF is the wrong scale! The part is supposed to be 0.87 of what the DXF came in as.
WHISKEY TANGO FOXTROT. Why would a DXF NOT preserve the actual size of the friggin' drawing???!!!
Try with the next cut... and yup, the DXF is too big. Scale it down by .87, and everything is good to go.
So then, this process wound up being much more labour intensive than I expected it to be based on the video example:
1. Slicer should be able to create native Fusion 360 objects and it should be able to hand them back to Fusion without needing file save/transfer hoops to jump through;
2. The objects should be transferrable either as individual slices or as (ideally) as parts laid out with the relationship between them preserved so as to be able to be cut from the stock extents;
3. As much as reasonably practicable, the shapes created for slices should use native 360 primitives (arcs, splines, etc) instead of polygonal segments;
4. The slices should preserve Z axis contours;
5. DXF export should maximize use of primitives (circles, arcs, splines) instead of polygonal segments; and
6. DXF export MUST preserve absolute sizes, so that DXFs imported into 360 are the correct size/scale.
I really REALLY hope this program gets some love, because it has SO MUCH POTENTIAL. It is great as a proof of concept, but it needs refinement on implementation/workflow.
Fusion
