<p>All my prints come out about 1 mm too short in the Z dimension. So for example a 20 mm cube comes out 19 mm high. A 10 mm cube comes out 9 mm high. The X and Y dimensions are fine. There's a little bit of visible elephant's foot at the bottom, so I assume whatever is happening is in the first couple of layers. The problem is fairly consistently around 1 mm even for larger prints.</p>
<p><a href="https://i.stack.imgur.com/Pjuev.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Pjuev.jpg" alt="10 mm test cube" /></a>
<a href="https://i.stack.imgur.com/RSPfi.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/RSPfi.jpg" alt="20 mm test cube" /></a></p>
<p>The printer is an Ender 3 Pro with a glass bed and BLTouch for automatic leveling, but otherwise stock.</p>
<p>I had a <a href="https://3dprinting.stackexchange.com/questions/13940/expansion-in-bottom-skin-after-first-layer">similar issue with another Ender 3 Pro</a> that was resolved thanks to a link to <a href="https://3dprinting.stackexchange.com/questions/8022/first-3-mm-prints-poorly-then-fine-after-that">this question about problems in the first 3 mm</a>. The solution was turning the eccentric nuts on the left and right to loosen the rollers that connect the X-axis gantry to the vertical posts. There the Z issue was not as pronounced, and I was getting really messy prints in the first few Z layers. Here that is not an issue; the first few layers look fine while they're printing. Loosening the rollers did not resolve it.</p>
<p>Things I've tried:</p>
<ul>
<li>Tightening and loosening the gantry rollers using the eccentric nuts. They're currently just tight enough that turning them moves the gantry, but loose enough that I can turn them without moving the gantry if I hold it still.</li>
<li>Tightening and loosening the two little screws that attach the extruder mount to the Z-axis lead screw. Currently I made them just tight, then backed off 1/4 turn.</li>
<li>Adding a shim between the vertical post and the Z-axis lead screw. The lead screw is now pretty much parallel to the post.</li>
<li>Slowly turning the lead screw by hand to raise and lower the gantry. There's no noticeable catching or increased resistance anywhere.</li>
<li>Varying the brand and type of PLA filament.</li>
<li>Varying the temperature from 190 °C to 210 °C.</li>
<li>Obsessively leveling and re-leveling the bed. Manually leveling, auto leveling with the BLTouch, and adjusting the z-offset.</li>
</ul>
<p>I'm using the stock Ender 3 Pro profile in Cura, and printing at 0.2 mm layer height. I've kind of run out of things to check. What else can cause Z height loss in the first few layers like this?</p>

[{'answer_id': 14870, 'author': 'SwitchedMode', 'author_id': 25422, 'author_profile': 'https://3dprinting.stackexchange.com/users/25422', 'pm_score': 1, 'selected': False, 'text': '<p>I have the exact same issue on my Ender 3 V2, perfect bed level using a dial gauge,\nperfect first layer test prints (printing 9 squares all 1 layer high).</p>\n<p>I can only get rid of it two ways:</p>\n<ol>\n<li>Using a Raft as you have said (annoying).</li>\n<li>Adjusting the Z-height Just exactly as the 1st layer finishes. I raise the height by 0.15-0.20\xa0mm (in my case), and the resulting elephant foot is about 80-90\xa0% better.</li>\n</ol>\n<p>I recommend you follow Luke Hatfields guide on Ender 3 rework for The X-Gantry, as well as his other sections. Youtube channel &quot;Edge Of Tech&quot; does a decent job covering the rework in video form. Following most of these reworks I have made everything else in the print absolutely perfect, unfortunately EF remains.</p>\n'}, {'answer_id': 16178, 'author': 'j_q_m', 'author_id': 28035, 'author_profile': 'https://3dprinting.stackexchange.com/users/28035', 'pm_score': 3, 'selected': True, 'text': '<p>Do you have any “slop” on the right side (non motor) of the gantry?</p>\n<p>I’ve noticed that my gantry will settle on the right side and lag behind the motor driven - ever so slightly - when it starts to drive up. It will, after that first lag, move fine for the rest of the time. Z axis travel seems barely affected but all my prints are consistently about 0.5 mm short.</p>\n'}]
['https://3dprinting.stackexchange.com/questions/14004', 'https://3dprinting.stackexchange.com', 'https://3dprinting.stackexchange.com/users/16902/']