Hotends where heatbreak is not load-bearing?

Having started with an Ender 3, it just seemed natural to me that the heatbreak should not be load-bearing; Creality's stock hotend has 2 bolts holding the heat block to the heat sink, which of course waste some heating power and increase the cooling needed to avoid heat creep, but serve the important purpose of keeping the nozzle position rigid relative to the carriage and making it so you don't bend or snap the heatbreak when changing nozzles.

Looking at hotends (especially all-metal ones) for a possible future printer build, I'm surprised to see that many (most?) don't have this property, and have the heatbreak playing a load-bearing role. This seems really undesirable. Only the Mosquito makes a point of doing this right, and supposedly has a patent on this or related design decisions. Is that really the case? Are there basic all-metal hotends that are designed to avoid making the heatbreak load-bearing that don't cost $150? 2 Answers The drop-in replacement all metal hotends for the Ender 3 that I've looked at seem to have the two screws -- though I've read/heard opinions that these are intended to be removed after assembly, these are common Mk. 8 type hot ends, but with 2 mm bore through the entire heat break instead of 4 mm. That seems to be the only modification (other than not anodizing the aluminum heat sink). While the brand name units of this type run approximately 65 USD at retail, they're available from Chinese vendors for under 10 USD plus a few dollars shipping, if you don't mind waiting a few weeks instead of a couple days to receive your part -- and if they aren't from the same production but sold without extensive vendor support, they're very close physical copies, according to review videos I've seen. It's also possible to replace just the heat break for similar cost, either in stainless or titanium, with a 2 mm bore unit; this would obviously preserve whatever additional mounting hardware exists on/between your original heat block and heat sink. BTW, if they aren't already, replacing the screws with stainless will significantly reduce heat loss through the screws -- stainless is a much poorer conductor of heat than common steels used with plated screws. • As mentioned in the question, I'm looking at this more from a standpont of a future build, not Ender 3; I just mentioned the Ender as the basis for what I'm used to. Maybe the right solution is what you're saying, just putting a suitable heat break in a mk8 type hotend. Are these readily available with proper mating surface to avoid clogging where they meet the nozzle? Jun 21, 2021 at 16:21 • @R..GitHubSTOPHELPINGICE I've seen them in both stainless and titanium on Amazon, never mind AliExpress. I recommend stainless -- lower heat conductivity and a bit cheaper, plus not prone to brittle fracture. I'd also suggest looking for a brass or copper heat block, it'll give less trouble at higher temps than aluminum. Jun 21, 2021 at 16:27 • I eventually ended up doing just what you suggested: replacing just the heat break with this: amazon.com/dp/B08TCD4M1S. Moreover, OEM-equivalent heater blocks and heat sinks are available dirt cheap (like 5 pieces for under$10) so this also seems like a very good way to go if you're not starting with a Creality printer but want a cost-effective and structurally-sound hotend. May 29 at 22:53

You ask in general, not specifically for Ender, so since you mention the Mosquito, which has a characteristic shape and a size, the obvious alternative which doesn't cost that much is the Phaetus Dragon.

It copies the idea of the Mosquito, but it is repackaged in a shape and size fully equivalent to standard v6 hotends so it's a drop-in replacement for any v6 hotend. You don't have one, but in general...

Footnote: Slice Engineering got the patent in US, but not in Europe and China, yet. Also, in Europe their idea apparently was found as not original. Who knows...

• Yes, I saw the Dragon (Phaetus = rebranding of Triangle Labs?) and it seems to be a near full clone (with better compatibility with other ecosystems) of the Mosquito and as such it's still rather expensive, and arguably also clones things for which Slice's patent is justified (unlike basic structural soundness with obvious prior art). I'll definitely consider it. Jun 21, 2021 at 16:18
• It's not clear who's cloning who. I heard that Phaetus is the original Chinese, and TL licenses it from them. This would make sense, since Phaetus still sells the product, while TL stopped due to pressure from Slice Eng. Concerning the features where the patent is justified, we can discuss it in the chat if you want, ping me in that case.
– FarO
Jun 21, 2021 at 18:43
• @R..GitHubSTOPHELPINGICE an advantage of the Dragon variants is that you can completely remove the circular v6 connector and screw the top of the heatsink directly to your carriage/toolhead (it is not warm anyway) which allows you to get a more compact carriage and a sturdier mount (it doesn't rotate when you change nozzle). By reducing its height this way I could fit a direct drive extruder too
– FarO
Jun 22, 2021 at 7:42
• Yes.. wait, the Mosquito can rotate on its mount? That's rather bad if it's not absolutely perfectly centered on the axis of rotation, since it will affect positioning accuracy... Dragon does indeed sound nice, but mk8 style has that property (screwing top of heatsink directly to effector plate) too and is a lot cheaper. Hmm, options... Jun 22, 2021 at 16:37
• @R..GitHubSTOPHELPINGICE no, but you mention a "future printer build" and I was thinking about v6 connectors, which are round and may rotate. Mosquito cannot rotate, it's screwed like the Dragon, just bulkier.
– FarO
Jun 23, 2021 at 7:53