3D Printing: First (bottom) layer has gaps
Channel: Roel Van de Paar
Date: 2019-06-30

3D Printing: First (bottom) layer has gaps


The Question: First off - I'm rather new to this and I might be on the wrong track
altogether...
I'm printing PLA using a simple DIY XYZ printer with a direct-driven extruder,
0.3 mm nozzle, 0.2 mm layer heights, using Slic3r. I've tried to calibrate the
bed as level as I can. I believe the distance to be OK because the skirt prints
in straight lines with no wobble.
While the overall results aren't that bad, I'm trying to improve the quality.
I'm not happy with the first layer: While it sticks to the bed nicely, the
printed strands are too far apart - there's a very noticeable gap between them
that I can actually see the second layer through. There appears to be a problem
with the second layer as well which always ends up too small (recessed). That's
only the second layer, though - from the third layer on, that problem
disappears.
What I've tried so far:
 * change the nozzle and/or bed temperature by 10-20 degrees up or down - no
 visible change
 * change the print speed (using the dial on the printer) - no noticeable
 change, especially when going slower
 * change the first layer extrusion width from 200% to 250% or 300% - that
 made the strands "flatter", but also made Slic3r space out the strands so
 that I ended up with gaps again
 * increase the extrusion multiplier - that seemed to help the first layer,
 but lead to over extrusion further up, so I didn't pursue that any
 further
 * manually increased the flow setting for the first layer in the printer
 menu to 135 - that seems to do the trick, but I have to turn the setting
 back again on the second layer
Now - is this the right way to fix this or am I just patching over an entirely
different problem that I just failed to diagnose properly? If it is the right
way, how can I tell Slic3r to either change the flow rate / extrusion
multiplier just for the first layer or increase the extrusion width without
spacing the strands further apart?

Solutions: Please watch the whole video to see all solutions, in order of how many people found them helpful

With thanks & praise to God, and with thanks to the many people who have made this project possible! | Content (except music & images) licensed under cc by-sa 3.0 | Music: www.bensound.com/royalty-free-music | Images: stocksnap.io/license & others | With thanks to user vwegert (askubuntu.com/users/4620), user Tom van der Zanden (askubuntu.com/users/26), and the Stack Exchange Network (3dprinting.stackexchange.com/questions/2943). Trademarks are property of their respective owners. Disclaimer: All information is provided "AS IS" without warranty of any kind. You are responsible for your own actions. Please contact me if anything is amiss at Roel D.OT VandePaar A.T gmail.com.