mitchfx
Posts: 184
Joined: Fri Feb 27, 2015 6:01 pm

Reducing gaps between outline shells and top surface fill?

Mon Mar 16, 2015 4:19 pm

I am still having issues with some of my top surface fill areas being too sparse, even after increasing my extrusion width from .40mm to .48mm (same value as auto). I am also seeing a pretty noticeable separation between each of my 3 outline shells but not sure if that would be considered "normal". I'm printing at 0.10mm layer height in PLA and have set my speed multipliers pretty low as well to ensure a good quality print.

Aside from the extrusion width should I also try bumping up the extrusion multiplier from 1.00 to maybe 1.02? I finally purchased some digital calipers and this filament averages around 1.78mm although I've not changed my settings in S3D from the default 1.75mm. My assumption is that if I INCREASE the filament size setting then the printer will extrude LESS plastic...which would make my gap issue even worse???

Here is an image that might better illustrate what I'm seeing...
IMG_4376.JPG
Thanks,
M

mitchfx
Posts: 184
Joined: Fri Feb 27, 2015 6:01 pm

Re: Reducing gaps between outline shells and top surface fil

Mon Mar 16, 2015 8:23 pm

Not encouraging to hear ;)

What are you using instead? Slic3r? And what was your #1 issue?

-M

User avatar
jimc
Posts: 1124
Joined: Wed Aug 28, 2013 10:02 pm
Location: mullica, nj
Contact: Website

Re: Reducing gaps between outline shells and top surface fil

Mon Mar 16, 2015 8:27 pm

those are all nothing but adjustments. there is nothing s3d needs to fix. if your extrusions arent touching like shown on your outer perimeters then your underextruding. the actual extrusion width doesnt match what you have it set to in the slicer. this can all be worked out with a single wall calibration cube. basically if your extrusion width is .48 but your printer is actually extruding .43 then you need to increase the flow rate using the multiplier. as for the infill, that is the "outline overlap" setting. you need to calibrate your extrusion first though before you mess with the overlap. get that right first, see where you at and then if you need to adjust the overlap, go for it!

mitchfx
Posts: 184
Joined: Fri Feb 27, 2015 6:01 pm

Re: Reducing gaps between outline shells and top surface fil

Mon Mar 16, 2015 10:09 pm

this can all be worked out with a single wall calibration cube
Pardon my ignorance in this area, but is a recommended calibration cube STL or factory file?

Thanks,
M

jwellman
Posts: 14
Joined: Thu Mar 13, 2014 10:44 am

Re: Reducing gaps between outline shells and top surface fil

Mon Mar 16, 2015 10:30 pm

You could try the thin wall cube here (there are dozens of these on thingiverse...I just grabbed the first):
http://www.thingiverse.com/thing:507014

Be aware that if the wall is too thin that S3D may completely ignore it if you're extrusion width is too low. You can always tweak the wall thickness to get it to print this object (as the wall thickness here is 0.4 you'll likely need to set S3D to be 0.39). Then measure it and set the true value. Since you're just printing a single walled object at this point the extrusion width isn't all that important.

Thanks,
Jared

User avatar
jimc
Posts: 1124
Joined: Wed Aug 28, 2013 10:02 pm
Location: mullica, nj
Contact: Website

Re: Reducing gaps between outline shells and top surface fil

Mon Mar 16, 2015 10:41 pm

jared's cube is perfect. actually what you want to do is go into the advanced tab and check the "merge all outlines" box then go into the layer tab and choose 1 perimeter, 0 top layers, 0-2 bottom layers and set the infill to 0. print that and then take your calipers and measure the wall thickness.

JoeJ
Posts: 1436
Joined: Sun Feb 16, 2014 10:52 am

Re: Reducing gaps between outline shells and top surface fil

Tue Mar 17, 2015 6:35 am

I agree with jimc 100%. If you are seeing gaps between your perimeters, then you need to adjust your extrusion multiplier. There's nothing wrong with how the software is slicing the parts, you just don't have your extrusion rates dialed in yet.

There really isn't any special part that is needed for this. Just pick any cube and set number of perimeters to 1, use 0 top and bottom solid layers, and 0% infill. That will create a single outline print of the cube. Then you can measure the thickness of the walls. Increase your extrusion multiplier until the measured thickness matches the "extrusion width" value that you specified in your slicing settings.

Once they match, it would probably be useful to print the same cube, but now use 3 or 4 perimeters just to verify a real-world scenario. Make any final minor adjustments that are needed, and then you are good to go!

mitchfx
Posts: 184
Joined: Fri Feb 27, 2015 6:01 pm

Re: Reducing gaps between outline shells and top surface fil

Tue Mar 17, 2015 10:17 am

Thanks for all the replies. I am printing the thin wall test Jared posted now. Should I do my first tests using what S3D assumes is the "auto" extrusion width (0.48) and 1.00 multiplier?

jwellman
Posts: 14
Joined: Thu Mar 13, 2014 10:44 am

Re: Reducing gaps between outline shells and top surface fil

Tue Mar 17, 2015 10:25 am

I've never had great success with "auto" but it shouldn't matter for a single perimeter. You could try both and see if there is any difference. I typically leave the multiplier at 1 for PLA.

Jared

User avatar
jimc
Posts: 1124
Joined: Wed Aug 28, 2013 10:02 pm
Location: mullica, nj
Contact: Website

Re: Reducing gaps between outline shells and top surface fil

Tue Mar 17, 2015 4:34 pm

sure, start with the auto width and a multiplier of 1.00. auto doesnt do anything special except set the extrusion width to 120% of your nozzle dia. this is a good place to start tough. be sure you measure your filament and accurately set that in the software before you do any calibrations. you should run this calibration whenever you start a new spool then mark the spool with the settings that apply since every one is different.

Return to “Troubleshooting and Bug Reports”