Hi, I recently bough a .25 and a .15 nozzle for some jewelry prints. I have a bondtec extruder so I didnt have any big issues with the .25 nozzle. I dropped the speed down to 30mms and got some decent prints out. However with the .15 I noticed two things: First the cooling. The heat really concentrates in small models and I have to have at least to models on the bed at the same time so allow some time and airflow but that is doable even though annoying. Second underextrusion. In general I get good flow and im only printing at 20mms and I even disabled retractions, but I still get some clearly underextruded parts. I can see no leakage on my extruder and as far as I can tell not skipped steps. I dont know if im printing too fast but the speed doesnt seem excessive. Anyone want to share some experiences? Ill appreciate all pointers. Cheers https://reprap.org/forum/read.php?1,799126,799126#msg-799126 Mon, 16 Mar 2026 11:42:04 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?1,799126,799275#msg-799275 https://reprap.org/forum/read.php?1,799126,799275#msg-799275
Cooling: I have a good 360 cooling duct and i cranked it up to 80% which makes it better. The "two models 5cm apart method" seems to work best so far.

Extruder: Yes, i use a bondtec with 5:1 gearing and really short bowden, but I increased over extrusion to 105% that seems like a good idea in general.

Speed: Good point. I don't have a micro scale to test filament grinding/slipping, that would actually help here because one wouldn't here any grinding even if it happened.

BUT (big but^^) i noticed something else that had a much bigger effect and that is layer height. I had tested as low as possible and ended at 0.05 which is a bit too much in think. When I went up to 0.075 quality became much better. Its just a bit more volume and that probably smooths out a lot of issues.

Also with any layer heights below 0.075 i have the feeling that the x/y error/jitters are more visible that the layer lines, so decreasing layer height wont do much more for quality I think.]]> sungod3k General Sun, 03 Dec 2017 15:47:31 -0500 https://reprap.org/forum/read.php?1,799126,799180#msg-799180 https://reprap.org/forum/read.php?1,799126,799180#msg-799180 Going from a .25mm Nozzle (0,05mm²) to a .15 (0.018mm²) is a factor of 2.8, so be prepared to drop the speed not by 50%, as you did, but by at least 70% or even more.]]> Srek General Sun, 03 Dec 2017 08:39:56 -0500 https://reprap.org/forum/read.php?1,799126,799155#msg-799155 https://reprap.org/forum/read.php?1,799126,799155#msg-799155 o_lampe General Sun, 03 Dec 2017 04:12:09 -0500 https://reprap.org/forum/read.php?1,799126,799141#msg-799141 https://reprap.org/forum/read.php?1,799126,799141#msg-799141
As for the under extrusion, perhaps a little bit of extra extrusion after retraction will help the issue? Just a really small amount to re-prime the nozzle. What happens if you turn retraction off?]]> Origamib General Sun, 03 Dec 2017 02:22:47 -0500 https://reprap.org/forum/read.php?1,799126,799126#msg-799126 https://reprap.org/forum/read.php?1,799126,799126#msg-799126
I recently bough a .25 and a .15 nozzle for some jewelry prints. I have a bondtec extruder so I didnt have any big issues with the .25 nozzle. I dropped the speed down to 30mms and got some decent prints out.

However with the .15 I noticed two things:
First the cooling. The heat really concentrates in small models and I have to have at least to models on the bed at the same time so allow some time and airflow but that is doable even though annoying.

Second underextrusion. In general I get good flow and im only printing at 20mms and I even disabled retractions, but I still get some clearly underextruded parts. I can see no leakage on my extruder and as far as I can tell not skipped steps.
I dont know if im printing too fast but the speed doesnt seem excessive.

Anyone want to share some experiences? Ill appreciate all pointers.

Cheers]]> sungod3k General Sat, 02 Dec 2017 18:28:23 -0500