[Solved] MK4S with HF0.4 nozzle - no benefit against MK4 Inputshaper ?  

RE: MK4S with HF0.4 nozzle - no benefit against MK4 Inputshaper ?

What mode?  Speed or structural.  Prusa has stated structural may not change.   Also layer height may need to change to see full benefint of HF nozzle. 

I did a test on a part I have. Set layers,  Standard 0.4 nozzle, .2mm layer structural 49 min.   HF 0.4 nozzle, .2mm layer structural 45m,  change to speed 33min,    .25 layer speed, 26 min.  .25 layer structural, 35 min.  .28 draft, 22m.    

Variable layers added 

standard nozzle, .2,structural 59m,  HF0.4 nozzle .2 structural 55m, speed, 41m, .25 speed 38m, .25 structural 52m, .28 draft 35m.  

Using 2.8.1 RC1

RE: MK4S with HF0.4 nozzle - no benefit against MK4 Inputshaper ?

@vhubbard

Thank you for reply, I've double checked and cannot see a difference between the classic 0.4 nozzle and the HF0.4 nozzle. So the question is: System error or user error?

RE: MK4S with HF0.4 nozzle - no benefit against MK4 Inputshaper ?

Something seems wrong.   My MK4 Input shaper 0.4 nozzle  has .2 layer max, .25 is not available.    I am using PETG. 

RE: MK4S with HF0.4 nozzle - no benefit against MK4 Inputshaper ?

but you can manually set the layer height to 0.25

RE: MK4S with HF0.4 nozzle - no benefit against MK4 Inputshaper ?

Oh, Oh, Oh, I've found the problem: using an old custom filament-profile. If I switch to a system-filament-profile this inconsistencies are gone and the HFnozzle has shorter print time now.

RE: MK4S with HF0.4 nozzle - no benefit against MK4 Inputshaper ?

I use print settings, system presets for selecting layer height in the right menu.  When these change feeds and other parameters change.  If you just edit layer height, nothing else updates.     

RE: MK4S with HF0.4 nozzle - no benefit against MK4 Inputshaper ?

Glad you found it.   I find you have to ask for help and then it becomes obvious...   That happens to me often. 

RE: MK4S with HF0.4 nozzle - no benefit against MK4 Inputshaper ?

Same question here...
Just finished upgrade MK4 -> MK4S.
Using configuration assistant, I removed all MK4 IS presets, and installed MK4S ones, both HF and normal.
When I slice an object there is nil difference in estimated printing time between E.g. 0.4 nozzle and HF0.4 nozzle. Tried with structural and speed, with differents materials (PLA, PETG), there is abolutely NO difference in printing time.
Am I missing something here?

Also, on the printer itself, in the hardware menu you can choose nozzle diameters, but there is no option to specify HF. I guess this is normal as all settings are set in gcode?

RE:

Are you using PrusaSlicer 2.8.1? There is under Hadware-> Extruder-> Size a checkbox "High-Flow-Nozzle"...

RE: MK4S with HF0.4 nozzle - no benefit against MK4 Inputshaper ?

Filament profiles need updated as well.

Part geometry can affect this too. 

RE: MK4S with HF0.4 nozzle - no benefit against MK4 Inputshaper ?

I contacted Prusa support about this yesterday, and they told me that the slicer doesn't have profiles for the HF nozzle yet. So for now, you need to manually increase the print speeds. The recommendation is +30%, but it requires some experimentation; you can go even higher. Currently, I'm printing PLA at +50%, and everything is working fine.

RE: MK4S with HF0.4 nozzle - no benefit against MK4 Inputshaper ?

What's important here is to understand 2 things, what the nozzle does, and what the profiles do.

The High Flow nozzle allows the printer to melt more plastic in the same amount of time.  If a normal nozzle starts to struggle to melt plastic at 14mm3/s, the high flow will start to struggle at 20mm3/s (or something along those lines).  That's it.  The nozzle makes it so you can push more plastic through without failure.

The profiles are tuned to what Prusa thinks is best to work with the machine.  Whether they have profiles for High Flow or not, you can still easily take advantage of a higher flow nozzle, just by printing at the same speed with bigger layer heights, or by printing with the same layer heights at a faster speed.

So, if you have a profile you like for making brackets, with the new nozzle, you can print it with taller layers at the same speed.  This means fewer layers, and a faster overall print time.  Alternately, you can speed up the movement at the same layer height, so that it takes less time overall.

I think Prusa will probably limit the real benefits in their profiles to the biggest layer heights, because running machines at high speeds is really not always a great idea, and once you get beyond a certain point, you're going to have issues getting reliable results every time.

So, if you have the MK4S, and want to take advantage of the new nozzle, just use a MK4 print profile, and adjust the layer height, or adjust the speeds.  There you go, faster print times without the nozzle being the bottleneck that causes it to fail.

RE: MK4S with HF0.4 nozzle - no benefit against MK4 Inputshaper ?

As a sidenote, I did the MK4 to MK4S upgrade which came with a HF brass nozzle.  I already had a regular flow E3D ObXidian nozzle so I continued to use that rather than spending $60 for the HF ObXidian nozzle.  Using the MK4S profile, I have yet to ever have a problem with this non-HF nozzle. 

RE: MK4S with HF0.4 nozzle - no benefit against MK4 Inputshaper ?

Is it possible, that you are missing one speed limiting aspect?

Take a look at the different limits:
On one hand you have the print settings/speed settings
On the other hand you have the volumetric speed in filament settings (which depends on the selected printer model).
The limit, which is reached earlier, defines the resulting print speed.

The HF nozzle provides a higher volumentric speed per second.
If you print with 0,2 mm layer height using the normal nozzle, you will hardly reach the volumentric limit of that nozzle and the resulting print speed limit is the one set in print settings.
But if you print with layer heights 0.32 or 0.4mm, the volumentric limit of the normal nozzle limits your print speed.
Than the resulting print speed is limited by the volumetric limit (which is higher for the HF nozzle) and you should see the difference using the HF nozzle.

Hope this helps.

RE: MK4S with HF0.4 nozzle - no benefit against MK4 Inputshaper ?

I do understand the limits, but I was surprised when I looked that for the MK4S printer, the "High Flow" printer nozzle option was NOT selected by default, even know Prusa supplies one with the MK4S upgrade, so therefore, it can be assumed you have one.  Maybe even more troubling, is Prusa Slicer considers this setting an "Expert" feature, meaning it doesn't even appear unless you have your slicer is set to expert mode, and I'm guessing, many people don't have it set. 

Next I tried setting the "High Flow Nozzle" setting to OFF and ON and see if it made any time difference for the sliced models.  I tried big and small models with different materials, and for me, the print times were EXACTLY the same.  I'm doing this with a 0.4mm nozzle because that is the "High Flow" nozzle Prusa sends to you with the upgrade.  Is there EVER a difference in print times?  I have no idea, but there wasn't in the filaments I tested.  

So if this High Flow nozzle can really offer printing speed increases, Prusa don't make it easy to get, and I'm not seeing it.  Since Prusa turns OFF the setting by default for the MK4S profile, and they hide in "Expert" mode, despite the fact they give you the High Flow nozzle, that tells me they don't have much faith that its going to speed up your prints.