DIY High Flow 3D Printing Nozzle

Sometimes advances happen when someone realizes that a common sense approach isn’t the optimal one. Take radio. Success in radio requires bigger antennas and more power, right? But cell phones exist because someone realized you could cram more people on a frequency if you use less power and smaller antennas to limit the range of each base station. With FDM 3D printing, smaller nozzles were all the rage for a while because they offer the possibility of finer detail. However, these days if you want fine detail you should be using resin-based printers and larger nozzles offer faster print times and stronger parts. The Volcano hotend started this trend but there are other options now. [Stefan] over at CNC Kitchen decided to make his own high flow nozzle and he claims it is better than other options.

Don’t get too carried away with the DIY part. As you can see in the video below, he starts with a standard nozzle, so it is really a nozzle conversion or hack. The problem with high flow isn’t the hole in the nozzle. It is melting the plastic fast enough. The faster the plastic moves through the nozzle, the less time there is for it to melt.

Bondtech has a high flow nozzle that splits the filament into pieces to allow better heating of the filament. Apparently, they licensed this technology from a patent holder. [Stefan] was inspired and simply drilled a hole in a standard nozzle and inserted a copper wire. We don’t think the wire is actually dividing the filament stream, but it does transmit more heat into the interior. Or maybe the hot wire does divide the filament as it goes by, but at least some of the wires do not quite go right through the center. Anyway, he’s not selling the devices, so call off your lawyers.

The devil, of course, is in the details. [Stephan] shows how he soldered the wires using a high-temperature solder, cut them flush, and used an M6 die to rethread the nozzle. It doesn’t look hard, but it does take some care. Luckily, standard nozzles are quite cheap so if it takes a few attempts, it won’t break your piggy bank.

As usual, [Stefan] scientifically tests everything. You can see the difference between a normal nozzle and the longer Volcano nozzle along with the Bondtech nozzle. The homebrew nozzle with one wire was able to approximate the performance of a Volcano nozzle. Some more drilling and another wire offered even more performance.

This technique falls under a patent, so we don’t expect to see a lot of legal clones appearing. But if you are handy with tiny drills and solder, you can probably make these for your own use, at least in many parts of the world. However, since the performance is about the same as a Volcano, maybe just stick with that for now.

If you are interested in high flow, you may be wanting to build strong parts. Design can have a lot to do with that, too. This is especially important for — um — bridging.

48 thoughts on “DIY High Flow 3D Printing Nozzle

  1. Patents don’t prevent just selling a device but also making them. They’re there just to learn. It’s maybe murky waters to encourage others to make them. From a legal staindpoint. If this is sad news, call your law makers.

    1. Patents don’t actually prevent anything, they only give the holder legal standing to launch a lawsuit.
      Lawsuits are expensive, and complicated, and time consuming – even more so when they cross international borders.

      There are many cases of questionable organizations mass producing an obviously infringing clone product, selling quickly and being closed before the cease and desist letters even arrive.

      1. Do you have a reference for that?

        The patent owner has the right to exclude all others from making, using or selling the invention. There is no “selling only” or “personal use” clause/coverage/distinction for inventions in patents.

          1. Well, if you live in China apparently you are free to use other people’s patents for commercial use (effectively anyway….).

            UK and EPO still seem to grant “exclusive rights” to the patent holder, so I’m not sure where the “personal use” clause you claim comes from. Any references for that? (Kind of feels like more of the patent myths/falsehoods like that ones I grew up believing….)

        1. It’s quite a long time since I last looked at the topic, but I seem to remember that pretty much every member state has exceptions and limitations to the patent rights which involves private and/or non-commercial use.

          The only page I could find in English which lists the exception is the following (Under “Exceptions and Limitations of the Rights”):

          The following two snippets are from the patent law in my country:

          § 1.: ….obtain a patent for the invention and thereby obtain the exclusive right to exploit it commercially…

          § 3 section 3. 1.: The exclusive right does not cover acts performed for non-commercial purposes,

          1. Awesome! Thanks, that’s helpful!

            The UK has an exception for “Private acts for non-commercial purposes.”
            So it wasn’t a dream/fairy tale after all, it seems I did grow up correctly believing that you could use patents for non-commercial purposes (although I bet there are gotchas and limitations in there with the “privacy acts” part – i.e. if you not making money and nobody sees you…).

            Although the USA does not have a personal/non-commercial provision.

          1. That is not the same as the claim that you have permission to make things for personal use. A patent grants exclusive rights to make, use and sell.

            Also, it would depend on what the device in question was. If it was, say, some tool for repairing something that saves you significant money every time it’s used, then proving damages is not so hard.

            I would love for their to be a general ‘personal use’ clause for patents, and many people keep claiming there is, but nobody has been able to back this up. It seems it’s just more patent myth / disinformation…

    2. In most European countries, the exclusive exploitation rights granted by a patent are restricted to commercial exploitation. A private person who builds the patented invention in his own home for his own personal goals cannot infringe on a patent. The reasoning behind this is that such a situation cannot harm the patent holder.

      US law is more strict. It forbids anyone from making, using or selling the invention, even when the use is strictly personal. Of course, since patent infringement lawsuits are very expensive, a private person is rarely if ever prosecuted for using the invention in his own home. Such a situation could occur when a private person offers on his website a piece of software that uses someone else’s patented technology. The patent holder may feel that the freely available software threatens his commercial product, and then decide to use the patent to prevent the distribution of the free product.


    3. My point is that, if you take the law as it’s written (by the way, the only possible way) encouraging others to break the law by making a patented device, even for personal use, seems to be forbidden. And I don’t want this quite good news site to get into trouble. Hopefully nothing bad happens, but it’s not bad to understand the law. Had hackaday this clear before posting the article? I’m not sure.

    1. I liked these ideas and have high hopes that experiments will improve high flow nozzles even more. But frustrating to and sad to see such a broad patent (talked about in the video) being granted for a whole set of quite simple ideas.

      1. In general, the broader the patent, the more easily it can be challenged.

        Maybe “we” should do a gigantic “go fund me” effort to hire a bunch of (good) lawyers to go after patents of big corporations and/or publicize how their patents cost us lives and money.

          1. I don’t think “shorter nozzle” was the goal, but rather to go ahead and use the most common nozzle that you probably already have. But shorter nozzles do have the advantage of allowing for greater build height (assuming the rest of the machine allows for it). Generally, if you put a longer nozzle where a shorter one was, you will lose build height. As well, lower moving mass is “better” in some regards.

          2. The longer the heated zone, the less control you have at the nozzle. Think stringing and retractions. This could also work with the Prometheus multi material system. Furthermore, why change hotend to volcano for worse string always when you can just nozzle swap

  2. Increasing the nozzle temperature will have a similar effect. You’ll need to tune the temperature increase to the feedrate to get the right exit temperature, as in the delta_T will have to adjust up and down as the feedrate changes. You should be able to drive the nozzle much harder that way without any physical modifications to the printer. The limit would be the maximum power output of the nozzle heater, the maximum feedrate, and the lowest temperature limit part in the head.

  3. If an idea is dropped here, is it a proper prior art invalidating would-be-patents, or is that just an analog of releasing game into the wild right in front of hunters’ shotgun barrels?

  4. I got stopped by one of the first sentences: “Success in radio requires bigger antennas and more power, right?” — WRONG! It requires being smart with tech like FDM spread spectrum to use the same frequency for multiple simultaneous use. Also, that’s how GPS “works” with 31 sats on one carrier (different carriers for different needs).

    1. Well, you should have kept reading. Because that’s the next sentence. For years, people tried to build bigger better radios, but the cell system is possible because of smaller antennas and lower power allowing cells to use a set of frequencies and share them with other non adjacent cells. For most people, that goes against common sense and that’s my point. Common sense isn’t always right. By analog, we spent a lot of time trying to drive down nozzle sizes because intuitively that makes prints “better.” But now people tend to larger sizes for structural strength and speed. If you really want resolution, you should probably switch technologies. So that’s my point. That statement is wrong and it was used to make a point.

  5. This is what the *autotemp* feature of #ddprint is doing (,

    To put it simply:

    While parsing/pathplanning the gcode input, the needed volumetric flowrate is computed. Then the required (minimum) temperature for this flowrate is determined using a (automatically measured) material profile of the used filament.

    So when printing, the temperature of the hotend is dynamically changed in respect to the currently requested flowrate.

    This is done in a feed-forward manner because there is a delay between controlling the hotend heater and the change of temperature in the melting zone/nozzle, of course.

  6. Sorry but I can’t take you seriously after you say that a wire bisecting the filament flow path is not splitting it. I see, the plastic enters the 4th dimension temporarily and passes through the wire increasing the heating effect.

    Jokes aside…

    Stephen’s nozzle does the same thing the solex does. 1. Add more surface area to the filament melt zone 2. Minimize the thickness of plastic flow relying less on the plastic to conduct the heat to the center.

    1. I haven’t seen the patent, but any patent attorney worth his salt will use wording such as “a plurality of holes”. The whole reason you hire a patent attorney is to avoid dumb things like that.

  7. The UK has a clause in patent laws that says you can use it for non commercial use. God save the Queen.

    Also what are these companies going to do personally try to sue 100’s of people who would never be able to afford the fines anyway. So it would just end up costing the company.

    Its the crappy side of patents. I really dislike the notion that you can patent are really simple “idea” and then prevent others from using it just because you thought of it first. Fair enough if you’re inventing really complex ideas that took lots of time and money to research… but lets face it thats not the case here.

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