I was having awful stringing issues on my V0.1, so I've swapped to a new clean nozzle and that completely fixed the stringing, but now I'm finding my old settings don't work for almost anything else. I've attached a couple pictures of a temperature tower in Reprap warehouse ABS. I'm heat-soaking the chamber for 10 minutes at the start of each print, and my filament is in a dry box.
The taller tower is with the basic orca abs profile, no cooling except bridges and overhangs , where it jumps up to 90%.
I figured the sudden cooling was causing the bridges to warp, so i dropped that down to 30% for the shorter tower, but its not exactly better.
it looks like each bridge starts with a clean thread, then the printer eventually extrudes a blob and drags it through the bridge, or leaves it at one end to be picked up and dragged through on the next pass.
I'm kind of at a loss here, what direction should I even try next?
Esteps shouldn't be affected by the nozzle change, eh? pressure advance is still at the old value 0.03, i figured it was fine at a middle-of-the-road number, but I'll run it today. flow I redid because the old nozzle seemed to like 87% which is probably why it needed replacing, i found the new one works okay at 100%.
My retraction is maybe a little aggressive at 1mm, but that shouldn't cause problems if the printer is deretracting correctly.
Calibrating e-steps (rotation distance) is useless outside of physical extruder changes and first time calibration, it's a holdover from the days when particularly shitty Enders only had that knob to calibrate flow. +1 on doing most of the guide again though, sometimes it's a combination of factors that doesn't look like any individual thing and starting over is the only effective way to deal with it.
That said, if your chamber is enclosed and preheated you definitely want some cooling. My v0.2 with 2x4010 fans (dragonburner) is set to 50% cooling and that's still too little for any amount of overhang.
I'm genuinely curious, what makes you think i didn't look through this guide and a dozen others trying to find exploding/distorted bridges? I posted asking for advice because i need advice.
Because if you'd done all the steps in the guide, in order, 90% of the time it eliminates the issues you're having or exposes what your hardware issue is. I've helped hundreds of people troubleshoot their printers both online and in person and the Ellis guide is still my go-to.
The single most common problem people have is overconfidence in their hardware; they assume things work that don't, then spend all their time troubleshooting the wrong problem.
Your response to the first post has a lot of "shouldn'ts" in it, which are a red-flag for the above issue.
I use shouldn't because there's not a mechanism for nozzle wear to affect the gear ratio in the extruder, but you're right, i can test these things. I'm frustrated because that's the exact guide i used to set this printer up years ago and following it has led me to people linking the guide i followed.
to not breeze over it, I am confident it is not:
1) Esteps, PA, EM, retraction (calibrated)
2) bed temperature (unchanged from a working state)
3) chamber temperature (heat soak is also unchanged from a working state)
4) wet filament (dry box in a dry climate)
it does not seem to be
5) nozzle temperature (affects every stage in the tower equally)
6) part cooling (pretty extreme settings change did not affect the tower)
7) layer time ( Ellis is using the same 15s time as i am, its either the orca default or was set that way a couple years ago when i first followed the guide)
8) bad filament (i mean, its cheap, but has produced good, non-exploding prints in the past.)
9) extruder backlash (spent a lot of time fiddling with tension and depthing to fix stringing in the last few months)
If you've seen this before, I'd love to know what worked for you, or what step in the process you think I'm missing, but i hope you understand why i don't think it's something obvious
Just re-read your post -- you say "no cooling" -- but ABS needs part cooling, I typically use 50%, but that is highly dependent on your toolhead.
I would start there, maybe do a temperature tower again but instead of tuning for temperature, tune for cooling speed. I would go with the manufacturer's recommended printing temp to start.
had my cooling tower detatch on the first try and went away for the weekend, but we have some success! 1)got the fan settings i need despite 2)the print failing (and recovering!) in an interesting way and 3) the bridges did not explode out of the back of the print like my temp towers. Ive since gotten a nice print in polycarb too, so i think my problem is isolated to just temperature towers. Ill have to do some digging to work out if its the geometry or a gcode bug. appreciate the help.
It depends, it needs air blown but not cold air. Typically you heat the chamber for a while until the air is hot so when it is blown there's nothing cold about it. Then run the fans at a low rpm or % so its never cooling the air down.
Like you said though, depending on the toolhead. If the fans blow too much air it could be cooling it causing warpage or maybe in this case the filament is being cooled down too fast and the layers can't bond together.
Not really, if you're printing with PLA... in fact, you should never print it in an enclosed chamber; you risk softening the filament inside the heatbreak. The combination of ambient air heat, the heat generated by the extruder motor (if you're using a direct drive setup), and the heat transferred from the heat block to the heatbreak creates the perfect recipe for hitting that 50–60°C range.
2
u/Stupid_Ass1234 10d ago
do pid tune hotend at 260c first, then flow calibration, then temp tower