today is Dec 03, 2022

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.