Drooping on overhang
Just can't get rid of drooping on a overhang. I have a part that into which a 0.5mm thick display window slides. So it has a slot .7mm height with a 90 degree overhang of 1mm. At first the whole slot was drooping, but made changes below and now there is only slight drooping. The problem is I can't get rid of the drooping at the very beginning of the slot. That first corner laid down of overhang droops probably .3 to .4 mm. Don't want to use supports since I will be printing hundreds of these parts.
Using Prusa PLA on MK4 with slicer version 2.9.1.
Changes to try and get rid of drooping on overhang of the slot. These fixed most of the drooping except for start of overhang.
1) Filament Settings → Filament → Temperature - nozzle 1st 230, others 220, bed 60 both. Change to nozzle 1st 220, other 205, bed 1st 55 (lower warps) other 40,
2) "enable dynamic overhang speeds" was already set. speed for 0% overlap was 15, I am lower it to 5, 25% to 10, 50% to 15, 75% to 40%
3) Print Settings → Layers and Perimeters → Perimeters Default: 2 changed to 3
4) Print settings->advanced->overlap->infill/perimeters lowered from 15% to 5%
5) Print Settings → Advanced → Extrusion Width - Was .45mm changed to .48mm
6) Adjust Flow Rate for Bridges Using "Extrusion Multiplier" changed from 1 to .95
7) adaptive quality/speed changed from .50 to .25
8) Fan speed was already at 100% for bridge fan speed
RE: Drooping on overhang
You are basically printing a completely unsupported area so its bound to sag. I know you said you didn't want to use supports but you do realise you can use a paint on support enforcer just for that little area and change the support option to "For Support Enforcers only". That way you get supports only where you want them. Tiny bit of filament and a second to remove with a pair of needle nosed pliers.
Also check the preview and see where PS is putting the seam.
Anything beyond that and you are going to have to post your Prusa Slicer project file for us to examine.
RE: Drooping on overhang
Glad I'm not the first who has to point out that a 90 degree overhang is not printable. From the photo I actually have no idea what it really looks like or if there's a way to adjust the design. As Neophyl said, a 3mf is a lot more useful than a photo.
Formerly known on this forum as @fuchsr -- https://foxrun3d.com/
RE: Drooping on overhang
Can't wait to clean hundreds of parts, but I gave up and put in supports. First it is still sagging were it starts the overhang, It is less than without supports but still there, although it look more like a layer adhesion now. It is also not just an easy swipe to get out the supports either, have to work them out because they seem more attached than usual.
RE: Drooping on overhang
Just tilt the problematic walls and the printer will handle it. The modified window is in the attached file.
RE: Drooping on overhang
Miroslavs modified design of the windows is a good way to do it, IF the modified design still provides sufficient grip on your inserted window panel. Without printing one and testing that's an unknown though. If it does still fulfil the design parameters then Id go with that.
If you have to use the original design (which also has basically an overhang on the bottom fillet that will print problematically) then for supports something like in the attached modified project should be easy to do and remove. Running a dental pick or other similar metal tool like a small flat bladed screw driver along the groove will pop out the supports.
RE: Drooping on overhang
This will hold well enough given the printing tolerances. If there are any problems, a few drops of thicker superglue from the back of the profile are always enough. You can also adjust the bevel and edge of the part to be inserted into the frame. I have made a lot of such parts and their combinations and it always worked.
RE: Drooping on overhang
Tilting the walls works without having to work the part at all. There is a small drooping where it first lays down the slot, but it is not enough to prevent inserting the display window. Going to shorten the width because the display window now has some play on the short side maybe 1mm, but it could be used even as it is now. This solution looks very good and will save me from having to do cleanup on every part.
The modified 90 overhang supports produces a clean no drooping slot. All the supports are very easy to remove, except for the 2 on the ends where it first starts to lays down each slot. These 2 are like solid pieces that I had to cut out with a knife.
Is the "bottom fillet" the curved framed hole for viewing the display? Everything other than the slots, seems to be printing fine.
Why with all the methods is laying the start of slot overhang such an issue even with supports?