I just upgraded from a P1S to an H2S, and love it so far. One thing I looked forward to was easier nozzle changes. I rarely changed the P1S nozzle because it seemed like a hassle (I know, it’s not that bad, but it did deter me at times).
I just changed from the standard 0.4 HF hardened steel nozzle to a 0.8 HF hardened steel nozzle. Both brand new OEM nozzles. (I did change the nozzle type both on the printer screen and in Bambu Studio. No issues there.)
But when I print a model I’d just printed with the 0.4, it takes nearly as long with the 0.8 (~ 4hours). It’s a simple model, just stackable racks for filament storage. I was expecting some sort of amazing speed improvement. Am I doing something wrong? Or does a model need to be somehow optimized for a larger nozzle? When I watch people on YouTube, the larger nozzle seems to help a lot.
What’s it say the flow is? If its not near your max, defined in filament profile (new bambu software also has a nozzle dropdown in here too), then double check your settings for layer coolign times, max volumetric flow, etc.
0.8 is usually constrained by flow, but you can do the above with speed too to try to answer questions
A bigger nozzle doesn’t automatically make a print faster. The printer is still limited by how much filament it can melt per second, and the slicer keeps most of the same moves. If you don’t also increase layer height and reduce the number of walls/infill so the 0.8 mm nozzle can lay down a lot more plastic per pass, the print time will end up being almost the same as with a 0.4 mm nozzle.
The max volumetric speed is there for a reason.
Going higher will work to some extent, but it will reduce the quality of the print and have a negative effect on the layer adhesion.
The low volumetric speed is due to the nature of the PETG.
PETG HF has a higher max volumetric speed but is also giving in a bit on strength.
With PETG HF you see differences in time between nozzle sizes.
