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First Layer Gaps

Posted: Fri Aug 07, 2015 10:33 pm
by 3D-Print
Curious as to what others think about this.

I have noticed for the past month or two that when my first layer prints there is a slight gap between each "bead of ABS." It sticks to well to my PEI and doesn't curl lift or give any problems. Just doesn't look smooth and even. My second and subsequent layers looks good as you can see in the second image.

I can't find a setting I have inadvertently changed. Am I missing something?

I am printing HatchBox ABS at 220 with a bed temp at 90.

Thanks.

Edit: I use MatterControl and MatterControl slicer

Re: First Layer Gaps

Posted: Sun Aug 16, 2015 8:50 pm
by 3D-Print
I am printing the T-Rex skull for a friend. Ias most of you know it has a small footprint for adhesion to the bed. Using MatterSlice in MC the piece breaks loose despite adding brim (three touching loops) and/or a raft. The first layer "beads" are not tight and there is gaps as posted above.

Thus, today I used Cura slicer in MC and the first layer is tight with out gaps between the "beads" and I'm now 90% done and well past my prior fails with MatterSlicer.

Settings for Cura and MatterSlicer are exactly the same. First layer height is 0.2 mm, Hot End at 220 and PEI bed at 95. Using HatchBox ABS Black.

Any insight as to why MatterSlicer has the first layer gaps as presented above. I like MatterSlicer since it is more flexible in overall settings but may need to switch to Cura for small foot print objects.

Thanks in advance.

Re: First Layer Gaps

Posted: Sun Aug 16, 2015 8:59 pm
by 3D-Print
I have also tried to compensate for the gaps by Increasing the extrusion multiplier for just the first layer which I think helps but is only a bandaid not fixing the problem.

Re: First Layer Gaps

Posted: Mon Aug 17, 2015 12:32 am
by dajay23D
You can try to recalibrate z height and also the extrusion rates if u want to spend the time. Try to print the layer calibration disc to see if u see the same gaps. If curas working then it might not be worth the trouble. I have first layer adhesion problems with slic3r and it's a whole new a animal if I'm generating gcode from slic3r and importing in matter control. Not sure, I've noticed if I keep switching diff slicers and importing gcodes, it screw things up.

Re: First Layer Gaps

Posted: Tue Aug 18, 2015 8:23 am
by BenTheRighteous
Here's a hack:

There's a setting called "Bottom Clip" - set that to some negative number smaller than your layer height - let's say -0.08 to start with.
Then set the same negative value for "Z Offset" - those two settings together will effectively fool the slicer into increasing the extrusion for just the first layer.

It's not the same thing as increasing the first layer extrusion width setting, because although that setting does increase the extrusion width, it also spaces the traces further apart to compensate. My method keeps them where they are.

Re: First Layer Gaps

Posted: Tue Aug 18, 2015 7:31 pm
by 3D-Print
BenTheRighteous wrote:Here's a hack:

There's a setting called "Bottom Clip" - set that to some negative number smaller than your layer height - let's say -0.08 to start with.
Then set the same negative value for "Z Offset" - those two settings together will effectively fool the slicer into increasing the extrusion for just the first layer.

It's not the same thing as increasing the first layer extrusion width setting, because although that setting does increase the extrusion width, it also spaces the traces further apart to compensate. My method keeps them where they are.
Awesome. Thank you will try tonight.

Re: First Layer Gaps

Posted: Tue Aug 18, 2015 8:41 pm
by 3D-Print
Thanks BenTheRighteous!

When you mentioned extrusion width and what it does, I realized my problem. Many months ago I set my extrusion width to 400%. I'm not even sure why I changed that when I first started with my printer. I have attached a couple of images of matter control set at an extrusion width of 400% and 100%. Not sure why this actually showed up these past weeks but it did start happening after I installed a software upgrade.

As soon as my current print of my SD card, I will try a print. Of note when I used Cura slicer this setting remained at the default.