Additional mods for printing metal filled filament with Ender 3 V2?
There is a lot of misinformation in the 3D printing world about &quot;all-metal hotends&quot; being an upgrade. Some of them, especially clones, are not even all-metal but just poor lookalikes that create all sorts of problems. But even if you get a real one, it's a trade-off, not an upgrade. It lets you print materials that need a hotend temperature over 250 °C (over which the PTFE liner will begin to degrade and possibly release small amounts of harmful gasses) up to the temperature your heating element can achieve, at the cost of losing the extremely-low-friction PTFE pathway all the way to the nozzle, which aids with smooth extrusion and retraction and avoids jams. Depending on your particular all-metal hotend, it may be harder to get retraction working correctly than with a normal PTFE-lined one. Some users report very good results, others lots of problems.
There are very few materials that need temperatures over 250 °C to print that don't also need a much more expensive machine (or at least a heavily-modified one) for other reasons, such as requirement of a high-temperature enclosure. The main materials that can be printed on an Ender 3 with an all-metal hotend but not the standard PTFE-lined hotend are polycarbonate (needing 255-300 °C) and some forms of nylon (which may need up to 250-270 °C). All the other non-exotic materials, including PLA, ABS, PETG, and TPU, and even some exotic ones like POM (aka delrin or acetal) and many nylons, can be printed just fine with a stock Ender 3 (possibly with a minimal enclosure built around it).
In particular, for the purpose you want - printing metal-infused PLA - there is no point whatsoever in an all-metal hotend. Metal-infused PLA is printed within the temperature range of PLA, which is typically 230 °C at the absolute highest (and preferably much lower) and the printer you're looking at should print it just fine out-of-the-box (or rather, once you assemble it).
If you're concerned about abrasive wear from the filament, this affects the nozzle not the hotend. Technically the nozzle is &quot;part of&quot; the hotend assembly, but it's easily removable and generally considered a consumable item that you replace periodically. You can get hardened steel nozzles and all sorts of other exotic replacements designed not to wear out from abrasive materials, but the standard brass has the best thermal (heat conduction) properties and is so cheap you're generally better off sticking with it and buying a pack of 20 or so to have on hand when they eventually need replacement. In any case, there's no need to replace the hotend with an all-metal one to deal with nozzle wear; you can get either type of replacement to fit the original one.