Why does my print have extra layer(s) which keep moving parts locked?

Question

I just bought & received my first 3D printer and built it and tried my first print on it. It is this printer ELEGOO Neptune 2S

I printed the following item (chip clip) as a test.

The top of the item looks exactly correct.

However, the bottom (where the print started) is slightly "bonded" (still connected). If you look closely you can see the outline of the teeth.

Can you tell me what might have caused this? Am I using an improper material? (This was test filament that came with printer).

Was the printer not close enough to (or too far from) the bed?

Is there possibly something I should've changed in the settings of the drawing? I left them the same as they were in the downloaded file.

Answer 1

You have "elephant foot". Look at the left end of the grip section of the clip in your second image -- see how the thickness increases toward the top (which was the bottom, against the build surface, when printing)?

There are a number of causes for this; in your case, it continues for several layers, so the basic solutions (reducing first layer extrusion in slicer settings etc.) won't fix it; you probably have the same issue I do, with the Z axis not moving quite far enough on the first 3-4 layers after the initial.

I'd suggest you start looking for the solution by printing a calibration cube, and measure how much height you're losing. You might also want to draw up some simple calibration prints with one, two, three, and four layers to see the actual height those first few layers are getting, vs. what your layer height setting is.

This will help confirm the problem. Solving it might involve several kinds of tuning, but they'll all revolve around making the first few layer moves up from the start closer to their nominal height. Once layers 2, 3, and 4 are right, once you get a good initial layer, your prints will be significantly improved -- especially print-in-place parts like this one.