Combined/joined STL's - 'common layers' not slicing nice.

This is a trimmed-down example that demonstrates the issue I think I used to NOT have - but that may have been several upgrades ago - but I may be wrong - maybe just didn't notice before.
Anyway... all my efforts at making a combined (meshmixer) and joined (blender) and exporting/re-loading/repairing for slicing in Slic3r always has the result you see in the picture.
What do you think I'm doing wrong?
What is the correct 'Slic3r way'?
Is there a checkbox I need to (un)check?


(Nozzle diameter is 1.2mm (3D clay printer), 1mm layers )

Creation process... (after making BMP's in paint program)
Inkscape -> Import BMP -> Trace Bitmap -> path to OpenSCAD (3mm Z for petals, 6mm for circle)
OpenSCAD -> F6,F7 (each one).
Blender -> delete that stupid cube, import STL's -> Select-Object-Join -> Export as STL.
Slic3r -> Repair file (just in case it helps) -> ADD - Preview.

Must be a slic3r bug.
It works as expected in Prusa-slicer 2.2.0 (and yes you can use this, you don't need a prusa machine)

Yay!
Did not know of new Prusa.
I recall that I had investigated and dismissed it many moons ago - I think it may have been a 'Prusa-only' thing.
(I like the Mach3/CNC g-code from Slic3r for my 'gcode to IAI controller' conversion program.)
Thanks for the update/hope - am installing it now! :-)

Dust... Yay again! Looks great. Though it's a bit odd that the layer-by-layer preview is inverted - the layers disappear as you go up, rather than appear.
Not complaining - it's just odd.
BTW - my filament size is 76mm (3" PVC pipe). Today's nozzle is 3mm.
Am looking forward to cranking out things that don't need a 'pause and fix' operation! :-)

there are two slider controls top and bottom layer

Doh! :-) Ha - just had flashback to moment I discovered 'two-finger zoom'. :-) (Egads, over a decade ago?)

Have setup PrusaSlicer - Slic3r quite some time ago, well today I am printing the first Model.

Decided to test PrusaSlicer today as nothing else to do. My workload has dropped to the point of only working 2 days a week.
Sure am glad I decided to Retire 6 months early or would be as broke as a Church Mouse.

Today I am 3D Printing some Marvel mask ear supports protectors Using the Newest PrusaSlicer -Slic3r 2.3.0.
It started somewhat slower than Cura 15.04.6 will need to change some settings, though it is 3D Printing the Marvel Ear Supports

Edited 1 time(s). Last edit at 06/22/2020 09:31AM by Roberts_Clif.

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Computer Programmer / Electronics Technician

An observation ... about Blender object joining...
I just took a whack at using Blender to make superimposed text-on-text - background text 3mm high, foreground text 6mm high.
I forgot to do the 'join thing' before exporting as stl.
I imported into Prusa-Slic3r and the lower layers looked fine - tall characters were merged with the short characters.
Then I re-did it, this time NOT forgetting to do 'Blender/object/join' first.
The problem appeared - the tall characters only 'mostly' merged with the short text.
There is something odd about joined objects, stl's and Slic3r.
It seems that if mesh from 'object #2' falls within a closed-boundary loop of 'object #1' - it is ignored.
I.e., an 'L' on top of an 'O' will not do the 'L' part that falls within the 'O' until Z goes above the top of the 'O'.
So... try 'not joining'.