Bridging on inlet cone / bellmouth

[tired void]

Hi Guys,

I'm currently using a RatRig V-Core 4.1 500 IDEX.

I'm trying to print an inlet cone / bellmouth, but where the flange goes from flat to a curve, it seems to try to print a bridge in free air and fail.

I've tried this print a few times now, and the location where the "bridge" fails, as highlighted on the slicer screenshot in blue, fails in random spots each time I try to print it.

I've tried printing it with and without supports, without success.

This seems to be the only part I've had issues with so far.

Filament: Elegoo Rapid PETG
Nozzle: 0.4mm
Printing at 0.2mm

Using OrcaSlicer and the presets it comes with for Elegoo filaments.

Appreciate your help in advance.

[tired void]

Some more settings as per preset for reference

[tired void]

Bridging issue on inlet cone / bellmouth

[gilded sandal]

I don't think your first layer is going down correctly, it looks like on the left side of the circle you're too close to the bed, and on the right side you're too far (there's visible gaps between your lines)

[tired void]

It's weird, as it's in different places each time I try to print it.

That's not the first layer, its layer 2 when it tries to print this bit

between where the flat flange is and where the support actually starts

[deep chasm]

So you’re trying to print in thin air, don’t.
Either enforce support for initial layers, or truncate the model.
You can’t expect the extrusion to float in midair.

[tired void]

Yeah I'm not trying to do it on purpose, I just need some help with what I need to change in Orcaslicer to enforce the support on that part of the model, as the support seems to start a bit further along the bellmouth, as per the picture attached. (Blue part being what its trying to print "midair" and the green where the support starts).

I'm new to this, so just trying to get my head around it.

[gilded sandal]

@tired void Can you upload the Orcaslicer project file (the .3mf), I can take a peek to see if there's anything that jumps out at me.

[tired void]

attached @gilded sandal , cheers

[gilded sandal]

Yeah it's definitely trying to print in mid-air. I'm wondering if it's because the Support Interfacing can't actually get that low (due to minimum distances between the support interfacing and the mesh, and there not being enough room underneath the mesh due to how shallow the curve is).

You could try putting the whole thing on a Raft, which effectively makes the entire bed surface a support for a few layers, and then prints your mesh on top. @tired void

It looks like you have "Top Z distance" set to 0.2mm which says "Z gap between the support's top and object" - you need some value so that your model doesn't merge into the support, but my guess is that the spacing between your second layer and the build plate is less than 0.2mm so it can't actually generate support where it should.

Actually I looked a bit closer and Raft alone doesn't help.

If I set Raft Layers to 1, the first four layers now look like this. You can see in the second image that it gets a layer of support down underneath the area that will become blue/light blue, but there's still a 1 layer gap (that's the 0.2m Top Z distance in play), so that's still the same issue but now with a layer between.

Let me tinker some more...

If you want an easy win, enable "Make overhangs printable", it will change the geometry of your mesh (so you need to compare before/after and decide for your use case) but it seems to change the shape a bit like this (exaggerated), so that there's not areas with such a shallow curve. I didn't check to see what it does to the top though.

[tired void]

Wow, that’s brilliant, thanks for all the feedback, I’ll give it a go in the morning.

Cheers @gilded sandal

[gilded sandal]

Np, hope it works out for you 👍