I built my own high-flow 3D printing nozzle
by just soldering pieces of copper wire into a regular V6 nozzle with stunning results.
Can it beat a Volcano hotend or even de-throne the recently crowned king of high flow 3D
printing nozzles, Bondtechs CHT? Let's find out more! Guten Tag everybody, I'm Stefan
and welcome to CNC Kitchen. This video is supported by Curiosity Stream!
I recently showed you how with Bondtechs CHT nozzle you could almost print three times
faster because it can melt filament way more efficiently by splitting it into three strands.
The fundamental problem of heating a 3D printing filament is that the polymer conducts heat
very slowly. If you print fast, the material is not yet properly heated through before
it reaches the nozzle tip. By splitting the material up, you decrease the distance from
the heating surface to the center of the material, thus melting it more quickly. Bondtech licensed
the core heating technology from 3D Solex for their design and uses a quite sophisticated
machining approach to generate the shape. When looking at the patent, you can also see
other approaches to heat the filament not only from the outside but also from the inside.
One is a simple bar that's perpendicular to the flow direction. Hard to manufacture conventionally,
but what happens if we simply stick a piece of wire through a standard nozzle? This is
exactly what I did. I used a standard 0.6 mm V6 nozzle, a piece
of 0.8 mm copper wire, a 0.8 mm drill bit, and an M6 threading die. I first drilled a
0.8 mm hole 1.5 mm from the beginning of the threads. For that, I fixed the nozzle in a
vice and looked for an orientation where I could drill between two threads. Working with
these tiny drill bits isn't that easy, and I even had to change the chuck in my drill
press so that I was even able to mount the bit. During my investigations, I drilled quite
a bunch of nozzles but due to my crude setup was never able to hit the center perfectly
because the drill always wandered off. I'm sure proper machinists can tell me how to
do a better job. Then I used a piece of telephone wire that incidentally also just had a diameter
of around 0.8 mm and threaded it through the hole. Now I preheated the nozzle with my hot
air station and soldered the wire to the nozzle. This can be tricky because the nozzle sinks
quite some heat, so it takes a while until the solder properly flows! I made sure to
use lead-free solder that has a melting point of 227°C. I'm lucky that I checked before
I started because my usual leaded electronics solder already melts at just slightly above
180°C, which isn't suitable for our printing temperatures. Ideally, you should use something
with even a higher melting point like silver solder, but that would substantially increase
the efforts. Of course, we can't use the nozzle like this because the threads are blocked.
That's why I snipped off the ends of the wire and used a simple M6 die to recut the threads.
The copper and solder are so soft that I could easily do this with my fingers, also making
finding the beginning of the existing threads way easier. And there we have it - my DIY
high-flow nozzle. I call it the Mesh Nozzle. Though let's quickly talk about the elephant
in the room, and this is the patent. Yes, I'm pretty sure that if I sold this DIY high
flow nozzle, I would infringe on the 3DSolex patent. Luckily here in Germany you can recreate
a patented invention if it’s purely for private and non-commercial use. In the US,
even this is prohibited if there's a US patent! Making a video about something patented and
earning ad revenue might be a bit in the grey area, so I just contacted 3DSolex right after
my CHT video and had a lovely call with the owner of 3DSolex and the inventor and patent
holder of the Core Heating Technology. Carl is a super nice guy and also shares a great
passion for 3D printing which you can also see in his products like the high flow and
abrasive print cores for Ultimakers with swappable nozzles. If you ever worked with Ultimakers
you’ll understand my enthusiasm. Anyways – Carl gave me the blessing to play around
with the things mentioned in the patent and present the results to you.
Speaking of patents. I recently watched a really interesting documentary series on Curiosity
Stream about the European Inventor Award that’s a price awarded by the European patent office
which covered a ton of amazing innovations. Curiosity Stream, which sponsored today's
video, is an awesome streaming service that has thousands of high-quality documentaries
on topics like Science, Technology, History, Nature, Food, Travel, and so much more for
curious people just like you and me. The best thing is that you can get full access to their
whole library for only $14.99 a year, yes, year and not month, if you go to CuriosityStream.com/CNCKitchen
or use the link down in the description. The European Inventor Award documentary covers
topics like eco-friendly packaging replacements from funghi or high-performance plastics recycling.
Besides that, Curiosity stream has something for everyone with their award-winning exclusives
and originals and collections of curated programs. You can stream this awesome content anytime
on a vast range of supported devices! So if I got you interested and you'd like to check
it out and support me, give it a try by heading to CuriosityStream.com/CNCKitchen.
So let's get back to my investigations and benchmark the DIY high flow nozzle! We'll
look at two different performance factors this time because I noticed that a high possible
extrusion rate doesn't necessarily mean that you can also print well at these rates. The
first benchmark is the classical extrusion test, where I simply tell the extruder to
feed 200 mm of filament through the nozzle at different speeds. The faster we go, the
more backpressure we will have, which causes some slipping at the extruder gears and, therefore,
less material that comes out of the nozzle, which I can simply measure with a precision
scale. I did all tests on my E3D Toolchanger with a Hemera extruder, silicone socks over
the heater blocks while using standard PLA at 215°C hotend temperature.
To have some reference to compare the DIY version to, let's first test a standard 0.6
mm nozzle without any modifications. 5 and 10 mm³/s still worked well, and at 15 mm³/s,
we under extrude a reasonable 5%. Anything more than that is not really possible, and
the plot drops way down. Next comes the typical upgrade you usually get when you want to print
faster or with bigger nozzles– a Volcano hotend. Due to its longer hotend and meltzone,
the filament has twice the time to melt, allowing you to extrude more material. The Volcano
hotend with the 0.6 mm nozzle performed well all the way up to 30 mm³/s until it significantly
dropped. This is also well visible on the extruded material because starting at 35 mm³/s,
you can clearly see melt inconsistencies. The current king, the CHT nozzle is even a
bit better and shows a superb performance until 40 mm³/s and only then drops off.
Let's now get to the DIY high flow nozzle. It performed well at 5, 10, 15 and even 20
mm³/s, so it at least outperformed a regular nozzle. Even at 25 mm³/s, there isn't any
real performance drop visible. After that, we see the performance gradually decreasing,
interestingly in a very similar manner as we've seen with a volcano hotend, which is
pretty impressive! But let's take a look at the geometry of our
DIY high flow nozzle. Adding the piece of wire significantly decreases the hole area
within the nozzle. This means that even though the wire is helping with the melt rate, the
added resistance again decreases the flow. I tried to get around this by increasing the
bore size where the wire is from 2 to 2.5 mm, so that the resulting surface is similar
to the unobstructed one. This adds an undercut at the transition to the heatbreak but from
my previous tests with Bondtechs CHT and print tests with this one, it doesn't really impact
retraction performance. I was even able to clean the nozzle with a cold pull!
Testing this design showed that this really significantly helped, and the drilled DIY
high flow nozzle performed great up to 35 mm³/s and only then dropped off. It didn't
beat the CHT yet, though I'm really getting close.
You may now ask yourself, if one piece of wire improves the performance that much, well,
how would adding two wires perform? That's why I modified yet another nozzle by drilling
two holes 90° apart from each other at 1.5 an 2.5 mm depth and again soldered wires in
and finished it up with a die. This one interestingly performed similarly to the volcano and the
undrilled mesh nozzle, which shows that a second wire on the one side might help with
melting. On the other side it adds additional turbulence and flow resistance which is detrimental
for performance. Just on a side note - the reason why the extrusion from the volcano
stay straight and the ones from my DIY high flow curl up are the unsymmetric nature of
my pin placement that cause an unsymmetric shear profile in the melt, making the material
bend up in the direction of the smaller hole. I talked about using two different tests to
benchmark the performance of a nozzle and the second one might even be more important
than the pure extrusion performance we just tested. If you closely watched the extrusion
benchmark before, you have noticed that the filament strand significantly changed shape
depending on the extrusion rate due to die swell. Die swell is the phenomenon that a
melted polymer partly tries to get back to its original shape before passing the nozzle,
resulting from its viscoelastic nature. The lower the viscosity before the nozzle and
the shorter time it has to pass through the orifice, the higher the die swell you usually
have. Die swell is caused by the internal stresses caused during compression that try
to release again. Suppose this prestressed material is printed and therefore basically
pinned on an existing layer. In that case, these internal stresses remain in the material
and can cause printing problems like warping or curling on overhangs.
To test printing performance and residual stress I designed a meandering part that I
print in vase mode at increasing extrusion rates by simply increasing the speed factor
every 5 mm starting from 10 all the way to 30 mm³/s. Printing problems at specific extrusion
rates can show in two different ways. Under-extrusion because the feeder is just not capable of
pushing enough material causing thinner extrusions or even voids in the wall. Then there are
printing problems caused by the internal stresses, especially seen at the corners. If the extrusion
line is prestressed, it tries to find a state of minimum potential energy, which I can simply
illustrate by a piece of pre-stressed rubber band that tries to snap back to a short line
instead of the elongated curve. Of cause cooling also plays some role here because if you solidify
the extrusion before it can deform, you freeze the internal stresses. Since I used the same
cooling solution for all of the parts besides the volcano, the results should be very comparable
though. So let's rank the different nozzles. The standard
0.6 mm V6 nozzle printed 10 and 15 mm³/s well but then spectacularly failed at higher
extrusion rates. This correlates well to our extrusion tests, where also at 20 mm³/s,
extrusion rates plummeted. Here it goes even all the way to the point that the lines don't
properly adhere anymore due to under extrusion and probably being partly unmelted. Next already
comes the Volcano hotend that's good until 20 mm³/s but then failed. I wasn't able to
spot significant under extrusion, but the internal stresses caused the corners to bulge
in. Interestingly, the next contestant is the
DIY Mesh Nozzle that was drilled bigger and landed in second place at the extrusion tests.
This probably means that enlarging the hole decreased flow resistance but somehow also
decreased the melting performance because the distance from the sidewalls to the center
of the material increased. Extrusion performance is a well-tuned system of flow resistance
and melting performance. Both impact the amount of material you can push through a nozzle,
but that doesn't mean that the extruded material ends up with the same properties. In third
place comes my first DIY high flow nozzle that performed well, all the way to 25 mm³/s,
and only then showed some degeneration. So now there are only two nozzles left. The
CHT nozzle and my double wire DIY high flow nozzle. Who's taking the win? Both nozzles
performed similarly in this test, and on the benchmark part that goes all the way up to
30 mm³/s no differences are visible. So, of course, I had to increase extrusion rates
and up the rate by 10 mm³/s each step to end up at 50 mm³/s on the top section. Here,
the CHT, unfortunately, takes the lead. Even though both show degradation in quality starting
at 40 mm³/s, there is more deformation with my DIY version and even a couple of holes
at 50 mm³/s. Still not bad for a first shot, or what do you think?
I think all of the investigations show the potential of different melt zone geometries
for high flow extrusion systems. Even though these high flow hotends aren't really necessary
for common printers using 0.4mm nozzles, I'm still excited to see what's all currently
happening in this field, even from other tinkerers. I think I just scratched the iceberg with
my tests because there are that much more things to investigate like different wire
diameters, the number of wires, geometries, positions, orientations, and materials. Plus,
the use of electronics solder limits the material choice to PLA and maybe PETG. Next, I definitely
want to try the same with volcano nozzles to see how much I can improve them! Of course,
much of this falls under the 3DSolex patent, so don't expect a ton of commercialization
soon, but there is still the option of licensing and smartly working around that patent. My
Mesh Nozzle also doesn't make the CHT nozzles obsolete due to their very competitive price
but might give you the option to mod other special nozzles. Definitely let me know your
ideas and thoughts down in the comments, and tell me what you'd like to see me investigate
next! Thanks for watching, everyone! I hope you
found this project interesting! If you want to support my work, consider becoming a Patron
or YouTube member and check out the other videos in my library! I hope to see you in
the next one! Auf wiedersehen and goodbye!
For the part: In CAD create simple 2D sketch then extrude.
For the test: Use the FlowTower script from the Cura Post Processing Plugin.
If you want a maximum extrusion test then this is way more efficient
That test is more about characterization of an extrusion system than calibrating flow. What is it exactly that want to do?