Couple printing quality problems. (Sorry for vague title)

[Lukephos 0]

I've been trying hard t print colourfabb Ngen with a stainless steel nozzle on my UM2+ for a while now, and am mostly there. I've got the first layer working ok, but I can't get much further. The main problem is the walls and infill of the layers past the first layer. If you look on the right most circle mainly you can see how it also doesn't stick and bridges. There's also the problem of a little sticking up after a retraction. It isn't bad for parts but in parts like the inner brim for the triangle gaps (shown in pic two) it's pretty bad and has caused it to peel a few times. This print is really meant for a brim anyways since it's to test gap tolerance, but I have no idea how I would start a print without one. Even with a brim I have to be there to remove the excess at the start so it doesn't get in the way and ruin it, and it still makes a dodgy start when I do. I've been recommended to make a little thing that hooks around where it extrudes at the start to remove it but I don't feel like that'd work. This print was stopped mid layer by the way, which is why some layers don't have the messy fill and walls. I've also included my current print settings. Thanks.

[neotko 1,417]

Steel nozzles always has the tip cooler, steel heats slower and cools faster than brass. Change to brass nozzle or raise the temperature to allow the tip to be at a better realistic temperature. Lack of layer bonding comes from the lower temperature of the tip.

You could swap to brass to check if that’s the issue or raise the temperature +10C an check if the material allows that much. Because the heater block will reach the selected temperature but the nozzle will be lower, this also means that for some materials this might cause Issues.

Simple solution is to print slower, less material moves, more material reaches the hotend temperature.

Also, fan might be forcing a even bigger temperature difference on the nozzle that can’t be seen since the heat sensor is on the block.

Ofc you could just use a brass nozzle since ngen isn’t abrasive afaik.

[geert_2 557]

Also, check if your bed temp indeed reaches the set temperature. If not, try in steps of 5°C more or less.

I had no problem printing NGEN on an UM2 (non-plus) with the default brass nozzle. So brass should work. It can be printed on bare glass without lifting (and even without brims), on the condition that the fans are off. With fans on, for models that do have overhangs and need more cooling, I need to use glue, otherwise I have warping. I used dilluted wood glue (about 10% white wood glue dissolved in water), which worked perfectly.