Wall thickness, layer thickness, and infill

I have a thin walled piece I have been printing. I have tried walls between 0.06 and 0.10 inches (OK, 1.5 mm and 2.5 mm), layer thicknesses between 0.09 mm and 0.19 mm. All with "full" infill. The actual infill varies from nothing (just two walls with a gap) printed at 0.80 wall thickness and 0.09 layers, to a nice honeycomb printed the same but 0.19 mm layers. Further, Z-Suite doesn't necessarily show what is actually going to get printed there, sometimes showing no infill but then printing it, or vise versa. Even more strange, in one part of the wall there is an interruption part way up that continues to the top. Below the interruption, no infill. Above the interruption, infill on one side of the hole, none on the other. 

Are there rules or guidelines as to what wall thickness with what layer thickness will result in a solid wall, and infilled wall, etc? Or is this a bug? That will be fixed by the next release (any day now  :lol: )?

Zortrax has had this problem for as long as I can remember.

When I ran some wall-thickness tests of my own (I think at 0.14mm Z) I noticed that 0.050" thickness was the biggest problem-child. Which is unfortunate, because 0.050" wall thickness is very common for plastic injection-molded parts. I'd suggest you print-out your own wall-thickness tests and try your best to avoid the pitfalls.

Otherwise its a sit and wait game to see if Zortrax fixes it in the next software update.

Thin walls have been the bane of my time with Zortrax. I knew going in from the forums that'd it'd be an issue, but I never realized just how aggravating it would be. We have been promised the next software version "soon" :rolleyes:  and my biggest hope is that they improved thin-wall performance. Okay, mini rant over.

Rule of thumb is to use multiples of the nozzle diameter +0.1mm. The ones that work for me very regularly are 0.5 (single wall) and 0.9mm (double wall). Sometimes 1.3 works on flat walls, but curves will come out as a separated double wall. On curves, I tend to be unable to get any infill between 0.9 and ~1.6mm, but it varies each time depending on the curve. The annoying bit is that it typically refuses to print infill until the wall is thick enough for it to do a zigg-zagg pattern; it absolutely refuses to do a solid three lines on curves. This is aggravating since 3 or 4 lines would not only be stronger, but it would actually decrease print time and wear on printer (faster, smoother travel) and increase print quality. Being able to choose the number of shells would help IMMENSELY here. (Please Zortrax. I'm not against begging)

Are you also seeing the Zcode layer depiction showing something different than what is printed? Because that is definitely happening. Fill shown where none is printed, or not shown where it is. 

I wish it where as easy as doing some tests to see what works. But I just printed something with 1.5 mm walls, the zcode showed no infill. What in fact printed was no infill up until there were some interruptions in the walls, then infill above that even though the wall thickness was identical and continuous. So there appears to be no way to know what you are going to get, other than actually watch it print?

To make it even more interesting, I printed a wall that was shown infilled and printed infilled. I had to adjust the position of that wall and did so, moving it about 0.005" with no other changes (thickness and settings the same). Now it is printed hollow. So it is not just the thickness or geometry, but also its physical location. To a user this looks random.

Sounds like similar experiences I have had.

Only thing I'd like to touch on is LabRat's "single wall" comment:

I've actually never been able to get zortrax to print single-wall... Perhaps LabRat has experienced single-wall printing when using one of the shell-like print features (but I've never used those features).

Are you also seeing the Zcode layer depiction showing something different than what is printed? Because that is definitely happening. Fill shown where none is printed, or not shown where it is. 

I wish it where as easy as doing some tests to see what works. But I just printed something with 1.5 mm walls, the zcode showed no infill. What in fact printed was no infill up until there were some interruptions in the walls, then infill above that even though the wall thickness was identical and continuous. So there appears to be no way to know what you are going to get, other than actually watch it print?

To make it even more interesting, I printed a wall that was shown infilled and printed infilled. I had to adjust the position of that wall and did so, moving it about 0.005" with no other changes (thickness and settings the same). Now it is printed hollow. So it is not just the thickness or geometry, but also its physical location. To a user this looks random.

Sounds like similar experiences I have had.

Only thing I'd like to touch on is LabRat's "single wall" comment:

I've actually never been able to get zortrax to print single-wall... Perhaps LabRat has experienced single-wall printing when using one of the shell-like print features (but I've never used those features).

Nope, single-thickness piece not a shell. I did a test piece to see if it'd work (it did) and haven't had a need to do it since. 

How did you achieve this?

any walls/ribs on my parts seem to be printed w/ 2-passes, regardless of how thin I make the wall.

Got a pic for proof?

:)

Nope, single-thickness piece not a shell. I did a test piece to see if it'd work (it did) and haven't had a need to do it since. 

I've actually never been able to get zortrax to print single-wall... Perhaps LabRat has experienced single-wall printing when using one of the shell-like print features (but I've never used those features).

I'm going to test it right now.. Looks like .020" will print single wall. (.51mm)  I'll let you know..

How did you achieve this?

any walls/ribs on my parts seem to be printed w/ 2-passes, regardless of how thin I make the wall.

Got a pic for proof?

:)

At work right now, but I may be able to dig up my test file later. The wall tested was a 1cm long straight free-standing wall on a 1mm thick base, so I cannot attest to whether or not it'd work in a real design application. 

Well a .020 thick wall still tries to put two walls in there. Caused problems and extruder started clicking on the second pass of every layer.. Not enough room to extrude.. lol

I'll try it again with a larger part tonight. It's possible that it was small enough I just didn't see any issues, though the z-suite showed it as only a single thickness. I'll report back in later. 

Well a .020 thick wall still tries to put two walls in there. Caused problems and extruder started clicking on the second pass of every layer.. Not enough room to extrude.. lol

Looks like I can confirm this. I guess the test I printed before was low enough that it was finished before having any issues. I guess this means that the only thin wall that we can print confidently is .8mm. 

Thats pretty nice actually.

Looks like I can confirm this. I guess the test I printed before was low enough that it was finished before having any issues. I guess this means that the only thin wall that we can print confidently is .8mm. 

There's a 0.5mm wall inside the control knob of a certain printer accessory that I manufacture. Guess I got lucky :)

There's a 0.5mm wall inside the control knob of a certain printer accessory that I manufacture. Guess I got lucky :)

How tall is it? I suppose that different configurations could make it possible to print (e.g. thin wall anchored between thicker features) but my test with a pure thin wall ended up exactly as Kyle said: it just tried printing two shells on top of each other. 

When I tried printing my fillets I drew the walls as thin as possible, til Z-suite did not slice them anymore. Result were always two passes, the surface was poor and the quality also.

The best way to print for my case is not to draw any thickness, close the openings at top and bottom, and use "mesh". The surface is as perfect as always, and its very easy to cut away the top and bottom surface. Result is an object that can bear any comparison with injection molding - only that my "mold", the zortrax, is good for any shape ;)

Funny that with "mesh" the printer also uses 2 passes. One in normal speed, one pretty fast, bevor platform lowers for the next round. Thickness around ~0,9mm.

And yes the structure inside an object can be as thin as 0,4mm, as well as the support. So the printer is capable of that, I guess its just a matter of software to implement it in Z-suite.

And I have to say that the printer is REALLY precise. Just by eyeballing it would say that it easily matches my CNC mill, a sturdy construction with high-end ball bearings etc. etc. Yes there are no forces and vibrations disturbing the printer mechanics, nevertheless impressive.

1254

Fillet mesh.jpg

regards

Andi

How tall is it? I suppose that different configurations could make it possible to print (e.g. thin wall anchored between thicker features) but my test with a pure thin wall ended up exactly as Kyle said: it just tried printing two shells on top of each other. 

It's very small - about 2mm tall and 2mm wide I think. But the Up slicer didn't even see it.

You mean its drawn in 0,5mm - inside this knob - and printed in 0,5mm? Its not a structure thats was created by z-suite for infill?

Interesting.

regards

Andi

You mean its drawn in 0,5mm - inside this knob - and printed in 0,5mm? Its not a structure thats was created by z-suite for infill?

Interesting.

regards

Andi

Correct. Definitely not infill (or support) as it's in the interior of a hollow tube (the knob shaft), the opening of which faces upwards.

Thank you.

regards

Andi