I find here many insterresting methods to evaluate the maximum volumetric speed. I also view some information about the Solex nozzle I didn't know. Your values for MVS and PETG are quite suprisingly high for a 0.40 brass nozzle.

I found another interesting approach by Stefan (https://www.cnckitchen.com/blog/flow-rate-benchmarking-of-a-hotend) you may already know. I think I will go its way to test some of my filaments and share the data too.

Did you have the chance to use your 3D Solex nozzles by now? What they are promising sounds very interesting but I find close to nothing regarding actual user experience.

Yes! I was in the midst of updating my notes pages when I diverted all my attention to COVID-19 response printing. I've got some raw data in the PDF linked to on my notes page that you can check out.

In short: Both 0.4 and 0.6 Solex nozzles significantly increased throughout. Surprisingly, PLA restricted rates more than PETG. With a 0.6mm nozzle, I could not extrude fast enough to cause extruder clicking when printing PETG at 250C, perfect for face Shields.

Surprisingly, the 0.8mm version was unremarkable. I suspect it might be clogged. Sadly, my focus is on the immediate crises, but I hope to return to more fun testing soon.

In short though, they won't guarantee good finish, but the Matchless nozzles can increase throughput with a V6 hotend to near-Volcano rates. Maintenance may be an issue, but the 0.6mm has done well with a half-dozen spools of PETG.

Did you have the chance to use your 3D Solex nozzles by now? What they are promising sounds very interesting but I find close to nothing regarding actual user experience.

I did do a bit of pre-order research, and apparently you can still do cold pulls with them. They look odd, but it works. I do expect them to clog more easily, so trying the larger sizes with filled filaments may be a challenge. I'd love to be able to print Colorfabb XT-CF20 at something more than 1mm^3/s... although 2 won't be that much more exciting.

Hang on there, buster. You just made me order a set of 3D Solex nozzles and now you're trying to sell me something else.

😎

But seriously... I did order a set of 3D Solex in 0.40, 0.60 and 0.80mm sizes. I'm very curious to see the results. This could be very useful for large functional PETG prints (e.g. bird feeders).

I'm very curious about your results with those, too.

Your design does look like it might be less prone to filament hardening and sticking.

And will still allow for cold pulls, hopefully.

Any plans to get some prototypes made?

I first need to do a bit of math to figure the best configuration out, the model is a mere 30 minute sketch of the idea. Standard E3D nozzles require custom made drills to manufacture, so I'll need to figure out whether and where I can get those made and then possibly have the nozzle made. (Another option is an EDM machine, but that also requires a custom form tool.) And the prototype will need to be polished smooth internally, because a rough surface could impede the flow a lot and make it not work. So yes, I'd love to have it eventually manufactured, but it won't happen tomorrow.

I have sketched out my idea for a nozzle that would have a bigger inner surface, allowing to melt more plastic, without impeding the flow of the plastic at the same time

Hang on there, buster. You just made me order a set of 3D Solex nozzles and now you're trying to sell me something else.

But seriously... I did order a set of 3D Solex in 0.40, 0.60 and 0.80mm sizes. I'm very curious to see the results. This could be very useful for large functional PETG prints (e.g. bird feeders).

Your design does look like it might be less prone to filament hardening and sticking. Any plans to get some prototypes made?

So - thinking I'll do a slow speed test, moving kilograms of filament at limiting rates directly on to the hot bed. Separate strips 1.5 expected extrusion width, printing at 25 mm/s or whatever the standard layer 1 rate is. If I modify a standard 100 mm square with 20% rectilinear infill I should be able to punch up the extrusion to make an acceptable test. It will look messy but the infill is a continuous pour, suitable for continuous extrusion rate testing..

I still think a cylinder in vase mode is a better test. There would be no acceleration affecting the E axis at all, whereas for infill, the extruder will be stopping at the ends. Yes, it'd require going through a slicer, but the total time to print would verify whether the slicer did any speed limiting shenanigans.