How to get rid of unwanted infill at bottom?

[gmc 0]

I have tried to find a solution to this but so far no comments or answers have helped me. Apologies if this has been solved at a place I have not yet found.

My problem is I cannot get rid of the bottom/infill (yellow) layers in my print that begin at layer 1 and continue to layer 37 before finally becoming the support structure (that I want from layer 1). What I keep getting is: layers 1 to 26 are infill (20%) and layers 27 to 37 are solid yellow. On top of that, from layer 38, the cyan support begins and continues upwards "correctly". But elsewhere in the model cyan support exists from layer 1 upwards, which is just how I want it. So in one place it works and in another something seems to force the infill.

My model is large and I have been forced to try making some void spaces in the model in an attempt to reduce the cooling forces pulling the edges up which has been happening mid-print. I use a brim and also have been taping the brim down quite fiercely (gaffer tape) to no avail. And I apply a good coat of ABS sludge on the buildplate before printing. I haven't yet resorted to building a cabinet for the printer to keep ambient temp up (ambient about 20degC here).

I intended to include pictures but after looking to do that the process of including them put me off (which may affect my chance of a solution I understand).

I have tried bottom thickness and bottom layers both = 0. Not fixed.

I have support enabled "everywhere" (I need it everywhere).

Just about everything else is default settings.

I have scoured the settings for anything else that might be related.

Is there some rules (either written somewhere or secret Cura rules) that Cura uses to determine where it forces infill? And can I get rid of it?

Helpful advice would be much appreciated. I'm using Cura 2.3.1

Thanks.

[DaHai8 74]

Did you try the Image Gallery button?

Its the next to the last button on you edit window.

Click on it, then click on "Upload Image". Drag-n-Drop your image into that window and then click on Add.

Its pretty straight-forward and doesn't require the blood of your first born or anything like that.

'Cause otherwise, I'm at a loss as your what you're trying to describe.

Sorry.

[gmc 0]

Thankyou. I had only discovered the URL link and upload to gallery (with a bunch of required fields) method or so I thought. My bad, glad I'm wrong

The pics show a few select layers in the layer view to show the problem. And a "stood up" solid view to see what the model is and to show void to the buildplate that I'm not getting.

It may be I'm doing something wrong. But I did notice during looking at this problem that when I increased the quality of the STL file the brim disappeared and reducing the quality again brought it back, so I'm not sure if some minor quirks are to be expected from time to time with this possibly being one.

[DaHai8 74]

Not sure what program you used to create your object, but it may be that it's not a solid manifold.

Have you looked at it in x-ray mode to see if there are any red areas? Those indicate problems with the model that the slider will choke on.

There are some online apps, like MakePrintable, that can check your stl file for errors.

That's all I got. Hope it helps.

[gmc 0]

Thanks for the tips. I'll check out the program and also see what x-ray mode says. I might have done something not quite right somewhere. At least it seems so far that it's not an obvious Cura setting I'm missing.

[DidierKlein 729]

You can also have a look at the mesh fixes options and play with them and check how it looks like. For me it's definitely related to the model.