u/Catsoverall

I'm doing highly detailed bottom surface tiny font work with 0.2 nozzles and struggling with reliability.

One of the primary issues is I can't stop the prime tower falling apart within a layer of two and that leads to debris dragged across the print. The prime tower seems to be generating a set of dry, fibrous, 'strings' (consistently long and straight) that aren't bonded together, despite the prime tower distance being at its lowest (100%).

Most recently I was stumped to get a nozzle clump on the second filament, only to find the first hadn't printed AT ALL(?). I tried that print again and found the hotend just...not moving. Nozzle temperature 140. No error message (it was "printing"!). Stopping the print did nothing. And...it was again, the SECOND filament (I double checked filament, print order, AMS match).

So I load up white thinking maybe somehow I have a nozzle block and the printer isn't noticing literally nothing coming out for a whole print layer and thought I'd film the loading purge. It's reliably not going down the hatch (not blocked). Does this time after time. Explains why I find the odd poop bottom of the printer. I had this before and answer a change of nozzle. I'm now thinking the fragile tower might itself be getting hit by debris from the nozzle loading process.

What should I be looking at?

PS: printing on a glacier, and there seems to be no difference in observed issues whether plate is freshly cleaned or not. Also seems to occur with multiple nozzles and multiple types of matte and basic PLA at a range of temps.

Panchroma PLA baaic, both stock & dried

H2C 2x 0.2mm Vortek nozzles

You're looking top down on layer 1. White prints first. Tiny font. Surprisingly doesn't look terrible in the end but trying to reduce smudging.

I'm blind and struggle to make sense of what I am looking at but it looks to me like white is fine and black is somehow both massively overextruded (the middle of the 0s looks crazy high compared to white) but also under extruded? (Gaps between lines).

Cool plate supertack and only way I could get these fine lines to stick is 0.24 line width and 0.12 first layer. If I do less of either some of the fine font lines pull off the plate.

The tabs have decreasing object flow ratio left to right for the black mesh.

Weirdly white has a much higher flow rate than black. Also much higher k value. Found super difficult to calibrate could have messed the read up.

White printing at 205, black I've tried 205 to 220.

In addition to telling me what I am looking at would welcome any tiny font tips for eg wiping, retraction, temperature, as there is a lot of conflicting stuff around and some standard techniques like wiping can rip up the font. I'm going like 10 speed abd 300 acceleration btw.

Thanks!

AI reckons this horror show of a K test is down to lines printing too close to the bed. That would align with other issues I've been having (decent quality bottom surface fonts).

But I thought H2 did this all automatically. Printer calibration done, bed levelling set to on. Correct plate selected. Filament dry. No gunk on nozzle after print (though I guess wiper may have got it off)

Fiberlogy PCTG, dried

H2C

Bambu studio

Flow calibrated

K calibrated

There are known bugs with the H2 series printers and pressure advance/some other unidentified issue and I may just have to accept good isn't possible, but maybe you guys can help :)

The paths are hyper extending over the wall. Slicer preview is fine.

I THINK - having ruled out practically everything else - that the physical tilt to sit on the wall also causes a visual dark border around the top surface. You will probably jump to flow/k but it isn't, pretty sure. In an attempt to eliminate both the extended lines and border I have tried:

Infil wall overlap

Monotonic line plus zero line extend

Different solid infil patterns

0,1,2, and 10- layer thick single wall.

Normal (3) walls

Different temperatures

Different fans

Different accelerations and speeds

Different top surface flow ratios

Different object flow ratios

About to try infil first but even if that works presumably I'll get a wonky wall sitting on top.

Losing it :(

Top surface horror show- help!

H2C left nozzle diamondback. Fiberlogy PCTG. Monoline solid infil, monoline line top surface.

Filament dried.

Temp tower very uninformative 235-255 all seemed ok. Changing temp doesn't resolve.

Flow calibrated but find this super hard.

K- calibrated...also super hard. Tried auto and manual.

I've tried seemingly endless combinations of infil/wall overlap, monotonic line travel extend (for the layer below top as believe it is ineffective for monoline line) and top surface flow ratio, as well as variations of k factor. :(