The thing is that changing the volume rate and not limiting the speed for cooling in the filament settings used to override any settings for the printer speeds. It would automatically adjust speeds. Now with the latest version, it looks like the volume rate in the filament settings is not applied. I was able to adjust the flow to 50 mm3/s and it would automatically adjust the speeds according to the flow rate. This would then cut about 1/2 the time off the print. As you can see in my earlier post, I used a speed benchy profile and changed my flow to 50 mm3/s and was able to print a benchy in 14 min 20 sec (print time) on my P1S, which was way faster than the speed benchy profile > 20 mins. I have opened up a bug report and will post the outcome, if any.
Then maybe the max flow overriding the process speeds was a bug that they have fixed now? I certainly want to be in control of the speeds of eg outer walls etc. If speed is solely determined by flow in the filament settings, then something is seriously off in my opinion.
Yeah. Maybe it was an issue that was fixed. Since then, they have added the two separate standard and high flow sections in the filament settings. But changing the max flow rate and not limiting speed due to cooling doesnât seem to do anything in terms of time. So Iâm not sure how those parameters are being used. The only differences that I see between the two different settings is the slight change in flow ratio and the max flow rate. It seems that the flow ratio is the only thing affecting the print time by a few seconds for small prints and maybe 15 mins for larger prints. So, if someone is printing small to medium sized prints, this nozzle is not worth the price. If you are constantly printing large volumes, then it may be worth it.
So now, I am performing a calculation between the flow rate that is in the program for high flow - 29 for PETG and adjusting the speed of the print using the settings on the printer. For example, if I want to print at 45 mm^3/s, then I just take 45/29 = 1.55, so I set the printer to ludicrous. Seems to be working for me this way. I also adjust the temperatures by 10 degs lower for initial and other layers.
In my opinion, the correct way to make use of the HF nozzle is adjusting the process settings in the left bottom panel.
Three settings govern the actual flow: in quality tab: layer height and line width and in speeds tab the individual speeds for the different line types.
The max flow in filament settings is really meant only to reduce those speeds if the max flow is exceeded by the above settings.
You are right, only bigger parts allow a truly reduced print time. But the HF nozzle has another positive effect: layer adhesion is quite a bit better at higher speeds than the stock nozzle.
My preferred settings for reducing print times:
- increase line width for inner wall, solid infill and sparse infill to ~ 0,6mm
- reduce inner wall count, so that you have the same wall thickness. e.g. for bigger parts I usually would use 4-5 inner walls. with increased line width, I only use 3 walls.
- increase speeds to ~ 400 mm/s for inner wall, solid and sparse infill.
I usually leave layer height at 0,2mm because higher layers have too many negative effects, especially on overhangs.
I leave outer walls at default settings to retain details. You can also increase
When you use the speed modes, all speeds and all accelerations are increased. it also ignores max flow, so you donât even have to bother selecting high flow nozzle or tuning max flow. I prefer instead to control all aspects individually and within the flow limit I measured.
29 mmÂł/s is very conservative in my opinion. Most filaments I tested had no problem with 40mmÂł/s. I think I tested Bambu PETG HF up to 45 and it still worked perfectly, it probably even handles 50 mmÂł/s. I just set max flow to 35 for all filaments, because I donât want to measure each and every filament and I donât have the need for higher print speeds. If reducing print time to a minimum is your priority, I suggest to test your filaments for maximal achievable flow before defects appear and set
3-4 mmÂł/s less as max flow.
This makes sense as to why the increase in flow does nothing for speeding up the print. I will try your setting out and see how well the prints come out. Thanks for the information.
Update - making two of the three changes above - 0.6, and increase to 400, did speed up the print time. I left walls at default just to see how these two affected the time. For a medium/large object it went from 14h 36m to 13h 34m. So this makes more sense since it has less lines to put down and the thicker lines can be placed down faster.
I guess you hoped for more? Which max flow rate was set? Maybe now an increased max flow rate makes a difference?
In the preview, color schemes âflow rateâ and âline typeâ are very useful to see, which lines take up most of the print time and if they already make full use of the possible flow rate.
No, this was actually a good amount of savings in terms of time. I just finished printing it and it came out looking really good. Thanks for the inputs.
I just wanted to see what the limit on this nozzle/printer combination would be in order to make quick prints (drafts). Iâll try tweaking some of your suggested parameters to get a faster print that does not have noticable imperfections. But for now, I have your settings as my main profile to use when printing.