Had a simple enough print to do I thought I just do a quick video shot to show the speed.
Video showing the Printing at over 400mm/s
Here is some pics from the slicer preview…
As you can see I could print even faster as there is still room in the flow rate.
But that’s fine as this maxes out once infill is combined.
Here is what things in the slicer look like using the standard profile and standard flow rates:
Quite a bit of time saved…
But what about the quality at those insane speeds ?
Of course you have to make some sacrifices here.
You can’t print at 400mm/s or more to then do the top layer at just 40.
High speeds mean using a higher nozzle temp and that does not go well with top layers.
So you print them rather fast…
As you can see the flow ratio is still a smidge too high for those 10mm wide arms but I prefer this over having issues with the flow ratio too low.
Top surface quality is good enough for my needs even without ironing.
The default 0.2mm profile prints much faster than the set 200mm/s because clearly this is just a value linked to the max flow rate.
For the standard nozzle and this PLA it was a moderate 21, the E3D is sitting at a moderate 39.
Any higher makes not much sense as the machine is already pretty much maxed out speed wise.
So what are the actual benefits of swapping over to a better hotened?
Speed is obvious here as print times can be reduced quite a bit if the filament and model allows for it.
For me though it the more consistent results.
The usual hassles with changes in flow rate/layer time are still there, like the banding where the legs ended and the pole mount starts.
But far less dominant than with the Bambu nozzle.
I don’t use high flow filaments, I use cheap standard filament I buy in bulk.
And being able to print those much faster than high flow filaments with the Bambu hotend makes it already a winner for me, the print quality is just a bonus.
What about other filaments than PLA though?
You CAN print basically all filaments much faster with these nozzles but it does not mean the print comes out ok 
Take filled filaments - it would be a waste to use these expensive hoteneds to save a bit of time for a few prints.
Once the inner coating is worn off many benefits go down the drain with it.
If you have to and can afford it go for it, otherwise stick with a harden steel hotend.
If you now think such a hotend would be the rescue for those slow TPU prints…
I tried and can get away with a max of about 100mm/s for simple and supporting models but around 80mm/s is the max if you want to rest assured the layer bond is great.
So not really much to save here speed wise.
The resulting print quality though is exceptional.
Cleaning and blockages…
The claim is you can just pull out the filament when it is cold.
While this will work for some filaments it won’t work well for others.
It is a bit like candy baked onto a non-stick pot - it WILL come off cold but is brute force really the best option ?
So far I only had one block, caused by being stupid after a little fault and leaving the hotend turned on to overcook the filament.
I was able to pull most of it out after heating the thing up a bit, came out rather easy compared to the Bambu hotend.
The black chunks I loosed up with a thin wire through the nozzle to free the openings.
Soaked the hotend for a few hours in MEK and flushed it using a (glass) syringe to get the remaining goo and gunk out.
Final flush was with white PLA coming out at 250 degrees Celsius.
Downsides and limitations…
Be it the E3D or one of the other high quality high flow hotends available now - our hardware is not able to fully utilise them.
Any nozzle size larger than 0.4 and the extruder won’t be able to keep up for combined infill.
Talking about max flow rates here that for a 0.6mm nozzle already exceed the 60 mark with ease.
The print speeds are also limited to around 500m/s for the hardware.
The slicer preview might show you 800mm/s but the print won’t come out any faster…
For tall structures, like tree supports a good plate adhesion is vital here!
Some filaments do curl up a bit and even without this the nozzle dragging over the surface provides some force.
Try to avoid crossing perimeters and if in doubt add a z-hop - should work fine in Orca, not so easy in Studio I think.
If you can’t be bothered to properly calibrate your filament then don’t bother with a high flow hotend!
All parameters have to be good enough and what let’s you get away with the original at normal speeds will come out as a mess with a high flow hotened.
High flow rates are not everything - not all filaments support high speeds.
Be realistic with your expectations - PLA and PETG are great here, TPU and such not so much if you are after higher speed that make a real difference.
The heater is also a limitation - it can overshoot and fall behind with those high flow rates.
Don’t be tempted to replace it with a 60W version or such!
The hardware only allows for a max of 48W and the PID control is matched for the Bambu hotend.
Unless you know of a way to adjust the PID values some overshooting has to be accepted.
You can compensate by making sure to reduce the speed/flow changes on a layer.