(NOW) SOLVED: Problem using variable layer heights

[bobstro]

I'm stumped with using variable layers on KISSlicer 1.6.3 Premium rel. Mac64. I'm getting this warning message about layer heights:



I'm using a Prusa i3 Mk3 and have created a printer profile for a 0.20mm nozzle:



I've adjusted the extrusion widths and layer info style settings:



And made the corresponding support settings:



The slicing completes, but I'm not sure this will print successfully. It's a 7 hour print, so I'd rather be sure it has a chance of success before throwing it onto the printer.

I've slowly figured out just about everything with KISS, and am really appreciating the variable layer heights, but this one has me stumped. I assume it has something to do with using a small nozzle size and corresponding maximum layer heights, but I am not spotting the requisite settings to change. Any tips appreciated!

EDIT: Setting fixed layer heights seems to have fixed it:



I'm not sure I fully understand it, but I assume the percentages were putting me out of viable ranges for the small nozzle.

[pjr]

Well found!

What setting do you have for Z-Step on the Printer/Hardware tab?

Peter

[bobstro]

Z-step is set to 0.0025mm.



Where I'm getting stuck is understanding the automatic variable layer height feature. I'm at the point where I change a parameter I think I understand, get the warning message, then can't get back. I've reset my profile back to the working settings shown in my last screen cap, but am getting the message again. It's unclear which of the 4 values shown is causing the problem and where to fix it. Any ideas?

I really like KISSlicer's variable layer heights, but am getting stuck hard adapting the presets to work with different nozzle sizes.

Thanks!

[pjr]

Rather than guessing, is there any chance you could zip up the model and project file so I can take a look?

TIA.

Peter

[bobstro]

I've (hopefully) attached the file KISSlicer Shermie Files.zip. This is the swoopy tank model I like to print instead of Benchy. I'm hoping to use the equivalent of Variable Fine or Variable Full style settings with a 0.20mm nozzle. I got very good results using Variable Full with a 0.60mm nozzle, so I must be looking for a parameter related to the nozzle.

I'm also not sure whether I need to worry about that warning message, but it's a long enough print I can't baby-sit it the entire time, so I'm hesitant to throw it at the printer.

KISSlicer's adaptive layers are quite impressive, so I really want to master them.

[hacker]

I have no idea how grave the warning is, but I know I did encounter it a couple of times with smaller prints and I completely ignored it because for some reason I was in a hurry. I understand the problem is that the thinnest layer based on the stepover settings, extrusion width and model geometry would be thinner (0.05) than the one you've specified (0.7), no idea how KISS resolves that, I'd assume by ignoring the stepover settings for a moment. I had no perceivable problems with my print.

But if you proceed, I take no responsibility

[bobstro]

Aha! I think I understand how the variable layers work. This configuration slices without complaint:



I think the settings under Layer Control work as follows:

• Layer Thickness (shown at 25%) is the minimum layer height to be used.
• Max (shown at 80%) is the maximum layer height to be used.
• 1st (shown at 0.16) is the starting layer height to be used (presumably on layer 1).
• Bottom and Top Stepover (shown at 50%) determine how much adjacent vertical layers overlap.

Using the convention of layer heights varying between 25% & 80% of nozzle size seems to have made it happy. I'm using 0.16 as 1st layer to stay at 80% of nozzle size though that's a bit thin for adhesion. My next step is to get less dramatic steps between layers, particularly as the curves move towards horizontal. I'm hoping adjusting Bottom & Top Stepover is the key. Unfortunately, I have to wait 5-8 hours to find out!

This all more-or-less matches what I read in the old 1.5 documentation, but the labels weren't matching up in my mind.

[hacker]

That's more or less how I see it, though I'm struggling to understand the difference between bottom and top. I mean like why would layer care what's going on on its top and why is it different, assuming the layers have the same extrusion width. So obviously I'm missing something here.

[bobstro]

I think bottom & top are separate simply so you can use more refined settings on the more visible surface, and use coarser settings underneath where overhangs and support concerns come into play. This might be useful for printing filleted edges on both top and bottom surfaces, where a coarser step on the underside might avoid the need for support, yet still allow smoother transitions on upper layers.

I'll have to experiment with this someday.

[hacker]

That's right, either get "official" answer or experiment, but I don't feel any pressing need to either demand answer or experiment so far