I'm trying to diagnose a print issue that looks like a missed layer (sorry, first-time printer here)
and
Specs:
- Printer: QIDI Tech X-Plus (direct drive).
- Material: PLA.
- Extruder temp: 200 °C.
- Bed temp: 60 °C (70 °C first layer).
- Print speed: 60 mm/s (actually 48 mm/s on non-infill because of
min_layer_time). - Retraction distance: 2 mm.
Started from a new printer: I was getting imperfect prints (lesser version of this, functional part) and contacted QIDI support. They eventually replied that my bed was too low but I had since lowered the bed on a misdiagnosis. They supplied a slightly modified G-code but that also failed in a similar way.
Since then, I've been raising the bed bit by bit to try to fix this issue. I don't care about the little whiskers much, but the solid "connecting lines" are a problem.
Questions:
- Is this actually a bed-leveling/height issue?
- What is this defect called (whatever the cause)? I've been googling but can't find something that looks like this.
- Is there a better way of fixing bed height issues than just printing->tweaking bed height->printing?
I'd appreciate any help diagnosing this issue - even if it's just the name of this problem. I have no experience disassembling/looking at hardware but I could always give it a shot.
Update
As per comments I took a look at coasting and ran some tests. I first re-leveled the bed manually (I'll call that height=0). I don't want to add tons of pictures so I'll show the baseline, and "bad" refers to similar failure as above.
+--------+--------------+------------+-----------------------+-----------------+--------------+-------------+
| | Combing | Coasting | Retraction distance | Extruder temp | Bed height | Results |
|--------+--------------+------------+-----------------------+-----------------+--------------+-------------|
| Test_1 | infill only. | off. | 2.0 mm. | 200 C. | 0. | Baseline. |
| Test_2 | infill only. | off. | 2.0 mm. | 200 C. | +0.05 mm. | ~ Baseline. |
| Test_3 | off. | off. | 2.0 mm. | 200 C. | 0. | Bad. |
| Test_4 | infill only. | off. | 1.5 mm. | 200 C. | 0. | Bad. |
| Test_5 | infill only. | off. | 2.0 mm. | 190 C. | 0. | TBD |
+--------+--------------+------------+-----------------------+-----------------+--------------+-------------+
(+/- 0.05 mm height achieved with clicks of "fast leveling")
Test 1 external view:
Test 1 internal view:
Update
I think I've confirmed an under-extrusion problem. Here is a top layer printing I stopped partway through.
This looks exactly like Simplify3D's Guide. So I manually pushed through, removed, and re-inserted the filament - and cleaned the nozzle with a brush.
I then ran a new print and noticed a clicking sound in the extruder (I don't know if it's new or if I simply noticed because I was focused on under-extrusion problems) - the print failed in the same "dragging" way as above, but the top layers were slightly better.
I'm now going through the list of possible causes of clicking extruder + under-extrusion.
