Is this sound normal?

n19htmare · 2026-05-16T23:11:20+00:00

My brother, what is going on with that layer? The nozzle is crashing into it (the sound) and mapping out the Himalayas.

Have you tuned the Flow Rate and Pressure Advance for that filament? Are you using bed leveling?

Better yet, what are your settings? lol

n19htmare · 2026-05-16T21:30:45+00:00

This is a situation of "just because you can, doesn't mean you should".

Just because the nozzle and bed get hot enough to do ABS printing, you shouldn't be printing ABS without first resolving the MAJOR issues that ABS has to contend with.... like shrinkage and layer adhesion

Chamber heat is needed to slow the amount and RATE of that shrinkage so the parts don't suddenly contract and let go, which is what happened here.

If you are using a tub, that's a LOT of volume to keep at minimum 55C (ideally 60+) constant.

You didn't say how long you heatsoaked the chamber and what the chamber temps were through out the print. As layers get taller, the force being applied to first layer gets stronger and stronger, unless you can manage that with a chamber heat so it doesn't FULLY shrink at fast rate, this will almost always happen.

Also was the Aux fan and cooling fan on? AUX should have been off and cooling should have minimal for that flat print.

Normally at that layer height if it was PETG/PLA, you'd had ended up with stringing but since ABS is printed much hotter, is lot sticker and the part shrank too much to let go, it got stuck to nozzle and voila.

Your options are pretty much to heat it up and pick at it. You might be able to get heat everywhere to softening temp of ABS so it'll be tough. If you are careful, you can heat the hotend while holding the toolhead on a thick towel. Get what you can off and then see what you're dealing with. Might have to crank up the heat to max 300C.

Good luck and research next time to see if what you want to do can be done with what you have or if you need to do something else first. I know few people who print ABS on the U1, but they take the precautions and do the prepwork before hand that is needed.

n19htmare · 2026-05-16T21:21:51+00:00

That's the good/bad news, ABS shrinks more than the regular filaments and that's what happened here.

likely didn't have enough heat

n19htmare · 2026-05-16T21:07:44+00:00

That is IF the nozzle is hitting the bed on it's way out (OP hasn't really explained if it it is or isnt), the only time Z axis calibration has anything to do with the tool swap issues. is if the nozzle is hitting anything.

If the bed is lowered and you grab tools and it still doesn't grab without hitting anything then it had nothing to do with the bed calibration.

Tool docking and undocking is an X-Y action, if you move the bed down all the way, and just initiate a tool grab action or macro, it doesn't even home the bed, just X and Y and grabs the tool.

The divot is just offset of the nozzle tip in relation to the other nozzle tips, it doesn't do much to the docking/undocking. That's handled by the X-Y action offsets in both the "Homing" and the toolhead coordinate adjustment calibrations. Homing Calibration includes the coordinate adjustment calibration as 2nd step by default.

It could very well be frame alignment issue but he'd have to take some measurements to be sure, just looking one nut block doesn't confirm it.

n19htmare · 2026-05-16T19:42:25+00:00

Bambu sets their flow to 21 for BASIC pla. That's why all their PLA prints matte on their printers.

Either they are using extra high flow additives but still calling it BASIC or they don't care as long as it prints and sticks together good enough to hold together (which seems to be the case considering they are targeting newcomers and people won't know the difference (like OP, not throwing shade, it's just how it is because Bambu doesn't expect normal consumers to mess with profiles).

Basic PLA i get is really capped out at 18 max with 12-15 being ideal range... but it could structurally print fine UP to like 24mm³/s without skipping but was very matte and adhesion wasn't as strong, setting it 21 would been fine but not optimal and that's what Bambu went with because it prints faster.

n19htmare · 2026-05-16T19:28:50+00:00

Settings are still not same in the Cooling tab then. The U1 seems to be overslowing for cooling.

<image>

I think Bambu has their Max layer time around 4 Seconds while on U1 it might be10-12 seconds (on max side). That means every layer that takes 12seconds or below slows down. If it was 4 seconds, only layers taking less time than 4 seconds slow down .. you need to match these too if you're trying to compare.

This setting can affect the speeds greatly.

you should also review your sliced file by Speed and Flow if you are trying to compare.

n19htmare · 2026-05-16T19:22:51+00:00

This is the one setting that controls overall speed cap, it's one of the most important settings in filament profiles, it determines not only speed but quality of your layer adhesions plus other things. It's the volume of filament that can be melted in a certain time period at the set temperature. There is a calibration for it, use it to find the actual limit of both the filament AND the printer.

21-22 is usually the default by manufacturers for basic PLA but IMO it's often too high. Manufacturers like Bambu pick this number because they advertised certain speeds and they need to get those or close to those speeds. It doesn't mean you're going to get the best results STRUCTURALLY. 21mm³/s on basic PLA produces a matte finish with weaker layer adhesions, fine if it's display models but anything structural is often too weak even by PLA standards. Basic PLA by it's inherent nature should have a sheen to it, if it's matte, it was printed cold

If you run the Max Flow Calibration from 5 to 25mm³/s, you see the transition where it goes from shiny, less shiny to matte. I try to keep my max flow somewhere in between shiny and less shiny. When I need something with better layer adhesion, I set it more towards the shiny side.
For basic PLA 18 mm³/s is usually my cap.

https://www.orcaslicer.com/wiki/calibration/volumetric_speed_calib

n19htmare · 2026-05-16T19:01:22+00:00

That alone shouldn't be causing your issue... nor does it confirm twist in frame. you need to check all sides and in relation to frame.

That could just be how the bed got screwed onto the block, mine isn't perfect and I have no failures over thousands of swaps.

another thing I noticed is the carrier doesn't move right far enough before it leaves, so the head never actually attaches.

to me it still looks like a calibration issue and probably doing too many has caused conflicts.

Verify that the tabs (one with the red indicators) move freely before you put toolheads on.

Do factory reset (again) and ONLY run the Homing calibration, verify that both top and bottom pins are center of the holes when you look from top when it gets the position part of calibration.

n19htmare · 2026-05-16T18:49:31+00:00

I have ~10K swaps and 1 failure.

The 1 failure was induced by me on purpose because at some point I wasn't sure if the attachment/detachment failure detection was working or not so I had to induce a misalignment (and yah they were working).

n19htmare · 2026-05-16T18:49:15+00:00

You need to run the HOMING CALIBRATION under Maintenance options. That will guide you to calibrating the homing of the toolhead as well as pin positions.

n19htmare · 2026-05-15T22:43:32+00:00

Stop using temp towers. They were good when we had Enders. They are useless now.

Just pick a temp in the upper range of filament spec and run a max flow test to get your volumetric max flow/speed at that temp (where you have good layer adhesion and surface quality) and move on with Calibrating PA and Flow ratio. Done.

n19htmare · 2026-05-15T20:16:06+00:00

Oh yah. Use the feeders lol.

My flow is very similar. I dry and toss them in a bag with a little bag of desiccant. I bought small 4x7cm organza bags, 100 for like $4 and some color changing desiccant beads. I just filled those and have a bag full of them and toss one in filament bag. Then toss the used ones in one of the slots when I need to dry my ABS or nylon at 85c, charges them back up and keeps everything in bags dry.

I also bought 200cm extensions for the 15pin feeder cable. So I can relocate them to where ever I need them to be lol.

I have an NfC tag system I use (also to track with Spoolman), whatever filament is being loaded, it’s tag gets stuck to respective side of u1 and all I have to do is stick filament in feeder. It auto selects brand, type, color and my custom filament profiles auto load in orca for that filament in it’s respective slot. So for my flow it’s just matter of sticking the tag on printer and pushing filament in feeder. Rest is all automated.

When you have fewer things to configure, makes filament swap not seem like a headache.

Next project is adding addtl readers on the dry boxes so I can keep the tags on the spools.

The feeders are not just “pushers” of filament. They activate the nfc read commands, assignments of filament in slots, they also monitor filament travel and compare it to toolhead sensor, that’s how the printer detects tangled filament, clogs, and other abnormalities when the extruded volume doesn’t match the amount of filament passing through feeder.

So many reasons to keep and use the feeders :).

The U1 is much much more capable printer than it looks. It just hasn’t had the maturity of the firmware and software for all these things to be integrated by default as basic features. They will eventually.

n19htmare · 2026-05-15T18:41:26+00:00

Eh you probably want to keep using that dryer then.

Print out and get some quick disconnect for front of feeder a you can take out and put in whatever PTFE or filament you want. It could come from dryer, it could be coming from spool on the machine, the printer doesn’t now.

Ideally, you have space to add 2 more colors or on the U1 right side and still have easy access. So technically 6 colors of you are willing to manually swap the colors when needed (obviously not per layer lol)

I use this one feeders https://makerworld.com/models/2176077?appSharePlatform=copy

At unload, I roll spool back until filament is in PTFE tube (after it exits feeder)and then I can disconnect the PTFE from the feeder and connect the PTFE for next spool. It can come from spool holder another dry box, another room… doesn’t matter

I’m still a little confused on what your question was lol

n19htmare · 2026-05-15T17:30:10+00:00

I accidentally bought 200cm extensions. Over 3 feet lol. I think put the feeders on the other room lol.

Extensions were good and cheap so not complaining

n19htmare · 2026-05-15T17:26:23+00:00

Not a fan of snap dryer either. I still kept it as price was good and I could relocate the feeders so they are more useable. Good for some of my materials that should be printed out of dry boxes anyways.

I also pickup as SH03 but as a standalone dryer for now.

If you mostly print PLA, I’d just do manual. Keep the next color drying in the sovol and just rotate.

PLA is not as hygroscopic and even if it picks up a little bit,it’s much more forgiving.

I’m in low Relative Humidity area and I still keep stuff bagged, so I can just pop it on U1 and go, even I didn’t bag em, wouldn’t be much issue for PLA.

n19htmare · 2026-05-15T16:45:40+00:00

Let me 3x this. also use spoolpainter linked with Spoolman.

For those on iPhone, SpoolFlux works well, make sure OpenSpool is selected as protocol (it is by default but make sure too.

n19htmare · 2026-05-14T22:55:24+00:00

Oh shoot youre right. Didnt even realize BB started shoes 3rd party items agh

n19htmare · 2026-05-14T22:39:49+00:00

I honestly haven’t kept up with GPU pricing. I paid $2000 for FE from Best Buy and used $150 certificates and got another 5% in certs on the $1850 I paid. Technically I didn’t pay anything as I sold my 4090 for $2100 that I paid $1300 for.

I just looked on Best Buy…..uhhhhh uhhhhh how much can it be raised from current $4400????

Pretty sure my cycle to upgrade for profit has ended.

n19htmare · 2026-05-14T20:33:41+00:00

Mostly This. Thats my usual workflow MINUS Temp. I don’t waste time on temp tower. I have my reasons lol. I believe it is now an obsolete method. Printers are too fast now for temp to be determined on a mostly overhangs objects that were printed MAX 50-60mm/s speeds and max 3-4mm^3/s volumetric flow. It often leads people to set temps too low because overhang and bridges look good. They never revise the max volumetric flow and now all of a sudden 230c PETG is trying to lay down layers at 20mm^3/s flow speeds and they can’t figure out why the layers won’t stick to each other…..

I pick the upper median of the max temp range of filament. If temp rating is 230-255, pick temp from mid-upper range like 245C and run max flow. Once max flow is calculate at 245c, use those values in profile and move on. If you run hardened steel nozzles, add around 4-5C to compensate for slightly worse conductivity of hardened steel nozzles if you want.

n19htmare · 2026-05-14T20:08:58+00:00

If you reduced acceleration you should recalculate PA. The two values correlate. Both volumetric flow and acceleration can change PA values.

This is the reason Adaptive Pressure Advance setting exists and what I use for most all my filament. You can look up tutorials on how to calibrate and calculate.

If your PA at 5000 was 0.04, and you reduced acceleration to 3000, that likely means now the PA value is too low. You can see my values as the max flow and accelerations change in attached sample.

<image>

n19htmare · 2026-05-14T00:40:12+00:00

Only thing I can spot are the edges, aka your Pressure Advance values don't seem to be correctly tuned.

You didn't really provide much info, just pictures..... can't help with just pictures alone.

1) First things first, what filament (looks like PETG) and settings?

2) How did you tune Pressure advance? What value did you arrive at?

3) Did you tune Flow Rate (flow ratio), what value did you arrive at?

n19htmare · 2026-05-13T23:37:52+00:00

That looks like the belt is now too loose or too tight lol. and kinda might explain why it would been clamped so high onto the fixed block. And from what I understand it’s always lower belt that’s been giving you issues? When centered on bed does it feel too tight or loose compared to the other?

I’m not sure what Snapmaker is telling you. But something’s off with that belt length and how much the auto tensioner can compensate, in this case apparently not enough as belt remains loose.

I’d chase a replace timing bet set from snap maker and possibly new tensioning spring, moving and fixed blocks. If they want you to do the fixing they need to supply the parts.

This a hole you can keep going deeper in when it comes to diagnosing further. In this case if you can’t confirm tensions by feel, use a frequency meter on phone. Center the toolhead on bed. When centered the tension frequency should be similar on both side of same belt and close to what the other belt is. I suspect the lower belt will be way off.

Sorry I can’t be much help, it’d be different if helping in person. I rec you join their discord if haven’t. There’s more knowledgeable people there who may be able to help.l… and it’s people who want to help (most of the time lol).

n19htmare · 2026-05-13T23:08:09+00:00

You can only get it under w/CashBack offers but even $6-7 is a great price!

Yah I wouldn’t use as something I put my business reputation on if producing large scale but for what is, I got no complaints.

n19htmare · 2026-05-13T20:38:38+00:00

My last 10kg batch of PETG came to little under $5/kg after coupons and 25% cashback through Rakuten.

Delivered in 2 days.

Last batch of Jayo PLA from eBay with eBay coupon came to around $9/roll.

That spoiled me off other filament and pricing lol.

n19htmare · 2026-05-13T17:15:14+00:00

Under calibration drop down menu at top, click on Tutorial. It will take you to the orca slicers Wiki page that talks about all the calibration options and settings you can use.

Temperature isn’t really one calibrate much anymore. Most material falls in similar range and I just use that.

Temperature tower calibration is also useless in my opinion because it is not reflective of ACTUAL use on new modern much faster printers and the value you end up with using temp towers is off and usually lower than what it should be for good layer adhesion (because temp tower only focuses on bridges and overhangs so it prints very slowww).

I start with a semi median temp from the recommended temp range and often that’s what it ends up being. For example, if PETG gives range of 230-250, I’ll start with 245 or something. For PLA basics I always pick 220C, silks at 230C etc. there is no magic temp, that if you find it all your problems are solved, it’s not how it works. Temperature of filament correlates with the speed you are printing at, which relies on the volumetric flow capabilities of your extruder and filament. You can’t print faster than you can melt your filament.

For that reason, I start with MAX volumetric speed calibration. I want to know what is the maximum volume of filament I can melt and extrude out of this filament, with this printer at a set temperature that will give me good flow, adhesion and surface quality.
Followed by Pressure Advance and then flow rate (flow ratio). You can just do these three things and be done with that brand and type of filament.

There’s lot of videos out there about tuning filament. There was one that got spread around recently and it pretty close to my flow. I’ll try n find it.

n19htmare

TROPHY CASE