SIngle nozzle width walls print bumpy

[movingimage]

My nozzle is .5mm, and I am printing at .61mm. I model my walls to be at least 2x the nozzle in nearly all cases. Sometimes I design-in my own supports, and in those cases I make .62mm walls as supports to save time and material. These walls print as a huge bumpy mess. The printhead bumps and bangs along as they print. Seems like huge overextrusion to me, but not sure.

The image from the slicer shows a single perimeter with no gaps or infill as you often get when walls are smaller than nozzle size. In my case the extrsuion width is smaller than the wall width by the minimum needed to get a solid wall tool path (.01). As you can see in the pictures, the 1.2mm walls print smoothly.

Thoughts or suggestions?

[dkightley]

This may sound ridiculous, but I'm very interested in what's happening with your single width extrusion....as I would love to be able to produce this behaviour...as opposed to stopping it!

So...if someone can help you stop the effect, then it may help me actually create it!

Would you be able to attach your factory file so I and others can see how you have things set up.

[movingimage]

Ha! Sure.

IB03 Thick Bottom 2.factory

(449.64 KiB) Downloaded 241 times

Now, if anyone who doesn't like this behavior can offer a suggestion, I'd be so happy

J

[jimc]

yes i can tell you what is happening right now without even looking at your file! s3d cant print a single perimeter wall. its bumpy because its printing 2 extrusions, one one top of each other. print that again and pay close attention to your z stepper and when your printer changes layer height. i bet you this is what its doing. s3d will always put an extrusion on a surface. to make up your .62 wall you have an inner and outer surface. this is 2 extrusions. even if you look close at the picture, the bumpy wall looks all blown out. its also the same width as the 1.2mm wall even though its only supposed to be .62. there is too much material being extruded in the same place and nowhere for it to go except out the sides.

[dkightley]

Thanks for the info, Jim.

I bet its not often someone asks how to make something go wrong! I'm wanting to see if I can print a stone wall in 1/450th scale by the print process creating a horrible mess...which is what I'm wanting!! I can do some more experimentation....

I hope your info helps the OP as well!

[movingimage]

Jim,

Thank you. Seems like it ought to be able to recognize a single extrusion wall - if lets say it is within 5% of the extrusion width in size. Maybe that could be a software option. Instead I have to build all my custom supports double thick, which uses more material and makes them harder to remove.

Joe

[jimc]

there are settings for this. in advanced tab look at thin wall behavior and be sure the % of overlap is kept kinda low. 10% or so. also in the infill secion make sure the outline overlap is only about 10% as well. now this should keep it from doing what you have going on in the picture. as far as being smart enough to so a single extrusion.....that is a feature that has been asked for for years but we havent every seen it show up.