Printing single wall object?

[JBFUK]

Hi all,

First post. I have just bitten the bullet and brought Simplify3D after umm-ing and err-ing for a while. After just having two 4 hour prints fail due to an apparent slic3r induced Y-skip (both in exactly the same place, no apparent mechanical or electrical issues, other prints have passed this height fine etc) I finally got sick of it and decided to give Simplify3D a try.

I started with the default Prusa i3 profile and have added a new material profile for PETG which is the material I use 99% of the time. I have made minimal changes based on my 'working' slic3r configurations - simple things like bed area, G29 added to startup code, temperature set, manual extrusion width set to 0.5mm.

Generally when I get a new filament I print off two pieces which help me to tune, the extrusion multiplier. The pieces are a 2-euro coin calibration piece and a single wall tower.

The two euro test piece printed very well (considering a new slicer and I've done no tuning at this point) the coin doesn't quite fit so I think I'll need to reduce the extrusion multipler a little compared to the one I had set in slic3r.

The single wall test piece didn't print at all. The skirt printed around where the object should have been but that was it, not even the first layer of the object went down. This is exactly as shown in the preview - the object doesn't appear.

What gives? Any pointers on what I need to do here?

The STL of my test objects are here if that helps:

https://gofile.me/2yg11/KmFFixFLe
https://gofile.me/2yg11/dACj1I1Q5

[CompoundCarl]

The best way to do this is to enable "merge all outlines into a single solid model" on the advanced tab. Then change the number of perimeter outlines to 1, top and bottom solid layers to zero, and infill percentage to zero. That will always print a perfect single extrusion around the entire object using the exact extrusion width you set on the Extruders tab. This also has the bonus of allowing you to use vase mode if you want (can be enabled on the Layer tab), which can also help with a getting perfect calibration results, since it removes any retraction effects.

[dkightley]

The previous poster has advised you how to get around the reported issue for the purposes of printer configuration.......but for an explanation as to the real reason for your issue, have a look at this thread: viewtopic.php?f=23&t=3471

[JBFUK]

Thanks guys, I did eventually work out that I could use a solid object with 0% infill and one perimeter. I will try out the 'merge all outlines' option so that I can use my standard calibration piece going forwards.

One thing which I have found a slight issue with is calibrating the extrusion multiplier/width and getting good layer adhesion.

I'm printing in PETG at 245'c with no cooling fan. Using slic3r with a manual extrusion width of 0.5mm (0.4 nozzle) I found the multiplier of 0.98 gave me the correct extrusion width for a single wall test piece and the two-euro calibration piece fits perfectly. The single wall piece is slightly translucent and layer adhesion is excellent - I can't pull the test piece apart by hand. Using Simplify3D with the same temperature and extrusion width settings (no cooling) I found I had to reduce the extrusion multiplier down to 0.96 to get the correct extrusion width for a singe wall piece and have the two-euro test piece fit. The single wall piece is more opaque and layer bonding much weaker as I can pull it apart by hand (seems more like when I print with slic3r using the cooling fan). For more solid models this is not a big deal but I would like to print an R/C airframe which is all single perimeter so the single layer adhesion is going to be very important.

Overall I'm now getting reasonable results but I guess it will take time to tune for specific usecases. I successfully printed some pieces that slic3r had messed up (weird y-axis jump) or wouldn't even render so looks like S3D is going to save me time with failed prints

[CompoundCarl]

Personally, I find the single wall prints can be a bit misleading, since the filament usually comes out of the nozzle in an oval pattern, and not a square, which is closer to what you will have in an actual print (since you will have multiple perimeters squished next to each other). So measuring the outer dimension of this oval extrusion can be misleading, and usually means you end up starting with an extrusion multiplier that is lower than what you need.

So if you're finding that the layers are not bonding together well enough, I would start by increasing the extrusion multiplier. I like calibrating it using the method described here:
https://www.simplify3d.com/support/prin ... gh-plastic

You basically print multiple perimeters and just increase the value until you see too much plastic between perimeters. After you get that right, you might want to read this part of their quality guide too:
https://www.simplify3d.com/support/prin ... -splitting

[JBFUK]

Thanks, these troubleshooting steps are actually really good. I suspect I could do with a very slight increase in extrusion however not too much as at 0.98 my two-euro test failed. I'm currently at 0.96 with coast and wipe disabled and getting reasonably good results. I'll continue to monitor my prints and use this guide to help tune out any other minor issues.

Also need to get to grips with supports as I've had one print with support materials that are impossible to remove.