Calculating volumetric flow rate for a HF nozzle, what multiplier should be used?
Calculating max volumetric flow rate is: print speed * nozzle diameter * layer height. Example: 200 mm/s * 0.40mm * 0.20mm = 15 mm3/s
When adding in a high flow nozzle, what is the rule of thumb? Just double it? So in this example: 30?
RE:
It's not exactly that. To calculate the vol. flow you use the layer width, not the nozzle diameter, Those values are usually similar but not the same, For instance, the standard layer width for a 0.4mm. nozzle is 0.45mm. but you can change that in the print settings, to 0.4, 0.5mm or any other value of your choice, provided isn't vastly different from the nozzle diameter.
Apart from that, high flow nozzles aren't different from the others in this matter, What it counts is the area of the filament layered and the printing speed, regardless of the internal structure of the nozzle.
RE:
I'm trying to understand though this example. Pick a preset such as Prusament PETG with a 0.4 nozzle. The max volumetric speed is set to 12 mm3/s. If I select the HF0.4 nozzle, then the max speed is set to 24 mm3/s
Trying to convert a filament manufactures recommended print speeds into volumetric speed. It seems the characteristic of the nozzle has an effect on this.
RE: Calculating volumetric flow rate for a HF nozzle, what multiplier should be used?
Of course nozzle structure has an effect. Volumetric flow is the throughput of the entire extruder SYSTEM as a whole. Its all a bunch of interconnected values. Increase printing temp and your hardware can handle greater throughput (till some other part maxes out). Change the heat zone , has an effect, change the cooling, has an effect. etc etc.
You can go by a rule of thumb or you can empirically test it to see what your hotend can do with the filament you are tuning for. Then set it back a bit to give you a safety cushion. Especially as the PS volumetric flow 'limit' isn't a hard limit and has at least one bug.
Any manufacturers example values are barely useful. Only useful in comparing comparative values between their own filaments as any values depend entirely on the hardware they are using to test with. Thats why comparing different filament manufacturers is also pointless.
RE: Calculating volumetric flow rate for a HF nozzle, what multiplier should be used?
Yes, I'm just using the manufacture's recommendation as a starting point. Then fire up OrcaSlicer and run the calibration tests. As an aside, why on earth does Prusa not include this in PrusaSlicer? I don't get it... Back to the subject, I'm just trying to understand how various nozzle geometries, not just high flow but different materials like Diamondback affect the flow rate. Assume for now keeping temperature and cooling constant.