Thin walls won't get infill

I have often that a thin wall will only print both outer perimeters, but not the infill.

So I will get a 2 lines outer side, a 2 lines inner side and between a space of approx 1 or 2 layer thickness.

My infill is default honeycomb. Is the space between the walls to smaal to put a honeycomb in ?
Can I change this ?

Thomas

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www.3daybreaker.blogspot.com

Orca V4.4 rebuild to Ramps with Mk8 and E3D, as well as a Rostock Delta Mini and an OLO in backorder :-)

Honeycomb (and 3D honeycomb, gyroid, etc.) infill is primarily for marketing photos of 3D printers or for the occasional print where the infill will be visible by intention.

All motion in the printer is subject to acceleration and deceleration. When printing long straight lines the extruder accelerates to the specified print speed, and then, before the end of the segment, it decelerates down to the jerk speed. In short segments, the extruder starts to accelerate, but it quickly has to decelerate because it is approaching the end of the line.
Honeycomb infill consists of a bunch of short segments in which the direction keeps changing. That means it is slow to print because of the short segments, and that it shakes the hell out of the printer because the direction keeps changing. It is probably no stronger than any other infill.

If you want your prints to be strong and finish quickly, you want to use infill that consists of long straight lines. That means you use triangles, grid, stars, etc. Rectilinear infill will also allow your print to finish quickly, but is not very strong because it is mostly bridging and the lines only touch where they intersect.

Edited 1 time(s). Last edit at 04/27/2020 10:18AM by the_digital_dentist.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Well,
helpful tips,

however this does not explain why the infill does not start.
See picture of my print ...



Both long sides have empty space where infill should be...

Thomas

Edited 1 time(s). Last edit at 04/27/2020 12:32PM by Replace.

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www.3daybreaker.blogspot.com

Orca V4.4 rebuild to Ramps with Mk8 and E3D, as well as a Rostock Delta Mini and an OLO in backorder :-)

Does the slicer show plastic going into those gaps? Try changing infill pattern, play with line widths, and increase the number of perimeters. Look at the rendered gcode in the slicer before you start printing to make sure it is doing what you want/expect.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

did you set "detect thin walls" parameter in layers and perimeters section?

Quote
the_digital_dentist
Honeycomb (and 3D honeycomb, gyroid, etc.) infill is primarily for marketing photos of 3D printers or for the occasional print where the infill will be visible by intention.

I must disagree with that assertion with respect to gyroid. I find gyroid to be fast to print, has the advantage of no crossing lines, and creates a high-strength part in all directions unlike 2D infill patterns like triangles, grids, or stars.

That said, I have also noticed the same thing as the OP: a thin wall may be thick enough for one or two perimeters but leaves a hollow space in between. The "detect thin walls" setting has never given me any satisfactory results, especially when my part involves sharp edges. It's really best if there's a thin wall connecting two other larger areas of the part. With a sharp vertical edge, "detect thin walls" usually creates a floating edge separated from the main part by a small gap. Because of that, some time ago I proposed a slicer modification for vertical sharp edges in the Prusa forum, but I was a newbie then and didn't know that a slicer forum might be a better place to propose it.