Looking at the chart on the BL storefront for the high flow ends they are the same as the .4 nozzle or worse for some cases.
So what’s the benefit?
Please understand I’m new to this and haven’t used anything yet aside from the included .4 regular nozzle that came with the rig
I just did a max flow test on 0.8 HF with ASA. The wall quality was ideal and shiny at 45mm³/s and still decent but matte at up to 55mm³/s. So YMMV depending on the filament you are using. In general 0.6mm HF will give some small flow advantage compared to the 0.4mm HF nozzle. 0.8mm HF usually will have similar flow to 0.6 HF, and mainly the advantage is just wider extrusion and higher possible layer height.
That is the main advantage of a larger nozzles, the ability to do larger layer heights. The max layer height of your print is limited to about 60-70% of the nozzle diameter due to the shape of the extrusion line. You can exceed that 60-70% limit but the wall quality will suffer. So for 0.4mm nozzle 0.28mm is the max layer height. For 0.6mm its 0.42mm layer height and for 0.8mm nozzle you can go up to 0.56mm layer height. Together with the wider extrusion line, that allows you to print objects faster, but obviously at a lower resolution. So even if the flow might be very similar between the 0.6 HF and 0.8 HF, due to the higher possible layer height and wider extrusion, it is possible to print faster with 0.8 HF nozzle but at a lower quality.
Keep in mind both the 0.6mm HF and 0.8mm HF nozzle profiles need a lot of manual tunning to get the most out of them.
Thanks for the info.
But what about the HF versions? Do they still fall into your layer height %’s?
Yes the 60-70% max layer height rule applies to all types of hot ends, no matter their internal design.
I think the 60-70% rule applies not to layer height vs nozzle size but to layer height vs line width. In practice this was exactly the same until it became more popular to use wider lines than the nozzle size.
When I print in vase mode, I often use a line width of 0,8mm with a 0,4mm nozzle and it works beautifully (This is, on an X1C with E3D Obxidian nozzle).I think the possible line width is limited by the shoulder around the orifice. So if I want to go much wider than 0,8mm, then the 0,4mm nozzle wouldn’t work anymore.
I haven’t tried yet to print at > 0,24mm with 0,8mm line width, because a layer height of 0,2mm is already sufficient to reach > 40mm³/s at 300mm/s. So I would not gain any more speed by more layer height. If I want to, the 0,4mm nozzle allows me to use 0,4mm line width on the outer wall and 0,8mm for inside walls, combining good details outside and and high flow inside.
So for print speed, I don’t see any relevant benefit in a bigger nozzle.
In my opinion, the one point that still justifies them is filament with particles, like woodfill, glow in the dark, CF, etc. that might clog a 0,4mm nozzle.