RE: Slic3r adding support above print
Another side note, you shouldn't need any support on the top pieces, they build up quite nicely without support. At least the Zero does. I used 0.1 mm with 5 top layers and ... no issues I can see in the slice.
Ensure shell thickness also doesn't seem to be needed, which will help translucence.
RE: Slic3r adding support above print
Digging the support out of a 3mm slot is very time consuming and was the main reason for slicing it “upside down “. During revamp I changed the wiring channel to a diamond shape so support is not generated deep in the channel. Just up to the lip on each side of the slot bottom. I also played with slic3r support parameters. It’s still unpleasant picking the support out of the slot bottom, but doable. Overall finishing time is reduced so thanks again for the suggestions. I also invested in a range of tiny picks and files, those help a lot.
I created a “phantom peak” on the top edge (well it’s now the bottom edge). The resulting plateau is high enough to firmly support the LEDs, and no higher. That happens to make the plateau a bit over 0.5mm. Then I went through the entire design and generally limited dimensions to 0.5mm or better throughout. Since the horizontal layers are 0.45 mm, that doesn’t affect the final part very much if at all.
I’m still tweaking, I’ll post more pictures once it’s closer to done.
RE: Slic3r adding support above print
It's been a while, but I've finally gotten the number 4 LED holder to print without supports. Upside down (or right side up?) as suggested. There were a few tradeoffs, but in terms of post-print assembly this design is fairly optimal. The tube that snaps over the top is still full of support, but with tweaked support parameters I can dig it out in a minute or two.
I dramatically increased the resolution of the exported .stl file, and dropped my layer height to 0.075mm. I haven't printed it yet but it looks very nice in slic3r.
I had to put in a few 0.1mm filets that I'm sure created surfaces more horizontal than without. This was needed at complex junctions with acute angles in the X/Y plane. The parts print fine without the filets (and no slic3r supports). I may not bother with the filets in production.
Here's the model, before the flip, to show the slot structure (now symmetrical):
Here's the sliced view, generated with "supports everywhere" but no supports were needed.
Again, thanks for the help and encouragement.
RE: Slic3r adding support above print
When you get this beast finished - share a picture of the result.
Love to see what folks can accomplish.