Please note that there is a mistake on the graph shown from around the 5:40 mark. The X axis has been labelled as "Flow rate (mm³/s)" but it should be "Time (seconds)"

Potentially the 0.8 outperforms the 1.0 because of cold core issues? Could be interesting to see if CHT changes that relationship

Good analysis man! Very good video.. I think, however flow test should also be tested while printing and seeing quality of plastic layed down.

Really enjoying all these in-depth analyses of extruders/hot-ends. Seems like with all these data -sets you could put together a quick reference chart for optimum flow rates (great datum by the way) for various hot-end/extruder combinations; similar to your proposed models for identifying ideal design parameters (got a good chuckle, cause my desk is exactly the same). There's already tons of examples out there for various CNC applications comparing speeds, feeds, cutter material, and stock composition. I'ld buy that poster.

I wonder if an extremely steep throat angle would be of any additional benefit. Whosawhatsis suggested to Sanjay a long time ago to move from the 120 degree drill tip, to a 60 degree drill tip for the E3D ends, and it resulted in quite a performance increase. I'd love to see a nozzle that used an even smaller throat angle - and I wonder if that might be able to help solve the cold core issues as the cross-section gets smaller over a much longer distance; both increasing the distance needed to fully plug the nozzle, and also reducing the diameter of the molten area and helping push that heat into the center. Unfortunately, not something that I have the tooling for. :(

I really appreciate all the time and work that went into this video.

I have a Mosquito Magnum hotend, best hotend I've ever seen!

That was a fantastic video! Thanks for adding some rigor to the field! I would be interested to see the average heating power vs flow rate. The 100 W spec for the heater is the maximum power when on 100% of the time (btw I've found that the resistance of heating cartridges can vary quite a bit, so 100 W may not even be the maximum power). Did you notice any temperature sag at high flow rates? If so, then a higher power heater will help as you've likely hit the maximum power for that resistance and output voltage of your power supply. If there is no temperature sag at high flow rates with a 50 W heater, then switching to a 100 W heater will likely not have much of an effect as the 50 W heater was not being used at 50 W to begin with. This can be used to determine if the bottleneck is the thermal conductivity between the hotend-nozzle system and filament, the power of the heater, or the extrusion force of the extruder-filament combination. Keep up the great work!

Great video! Keep on the great job man👍

Did you PID tune for the 100w heater ? Could explain the wacky spikes in extrusion force if the temperature varies a lot

Great VIdeo! First time viewer. Keep up the great work!

It could be that there is an optimum maximum nozzle size. It might be worth testing with a 3mm filament, an see how that changes everything.

But what's the print QUALITY like?

I think that in a standard bed of 20x20 not so much flow is needed. I have a bondtech CHT nozzle and use it on special prints, because, even If I wanted to print at a constant high flow, I have to add some time between layers to avoid melting problems (specially for tech materials printing without fan). So I can only print at a constant high flow on tech materials when the pieze has a very simple geometry without detailled zones. So for me the bondtech CHT nozzle made the volcano and mosquito obsolete at least for small beds

Wow this has got my head in a spin... I'm not sure extruder force equates to a 'good' print. (the force of the extruder could be applied slowly but up to higher pressure than a quick burst at a lower pressure (non-Newtonian fluids vs Newtonian). Actually flow vs expected makes sense. As does 'print artifacts' caused by insufficient melting of the filament cross-section when printing fast but I have no idea how to measure that. I'm not sure how common it is but I've seen speed benchys printed with Form Futura Volcano high-temp Pla so that definitely fits with your findings.. Making me question everything I though I knew....

I wonder if this relates at all to "time in the melt zone". As you're moving.. LOTS of plastic, you might not be melting a lot of the plastic that's extruding. Also, would "printing against something" make a difference? would it self limit the unmelted, or less melted plug down the middle?

Great stuff, I'd love to see you try different large diameter nozzles to see if the 0.8 > 1.0 diameter holds for nozzle types other than Bridge-Master. I suspect the internal geometry of the Bridge-Master is responsible for the confusing result.

Can this utilize CHT nozzles? Wonder what kind of a change that would offer.

are you running into limitations due to lack of tourq from the stepper motor

Learned I have too much money?

How are you getting the standard deviation? Maybe I missed something, but it appears you are calculating the sigma from just three samples. If that's the case, then you will have an incredibly-low statistical significance, meaning those values will be mostly noise. Yes, you can fit a Gaussian distribution to just 3 points, but it's not meaningful. Again, apologies if I'm misunderstand your method.

That first plot is very confusing with the x axis labeled as flowrate. You call it time in the video.

Very interesting video! I have subbed for more videos/tests like this! In the last 2 days I have built a heat transfer model for 3D printer hotends. One key parameter that has become increasingly apparent from my model is that SMALLER internal diameters lead to increased heat transfer rates to the filament (this is because of the increased surface-area to volume ratio). This may partly explain your odd results with increased force for the largest nozzles you tested. The temperature gradient must flow across a larger radius of plastic with a poor thermal conductivity at the end of the nozzle. My model does not examine extrusion force, which is obviously a key factor in real world performance of hotends. Let me know if you are interested in seeing my heat transfer model. Also, as previously noted, I believe there is a mistake on the graph at 6:20 in that the x-axis should be labeled Time/Seconds instead of flowrate.

4 to 5 seconds to normalize...not 45 seconds as I initially heard it.

I like your content but i believe you would benefit from shorting down your clips. Going from 30 min to say 10 min would probably be better.