[Bald & Bearded]

I am in the process of evaluating multiple all metal hotends for their suitability for multiple materials. I am primarily focusing on PLA, ABS, and Nylon(Taulman 618) but hope to test different flex and other materials.

There are several aspects of the hot end that determine how well it does with certain materials. Two big ones are the materials of the hot end (J-Heads and many others use PEEK for cooling fins and PTFE liners for the filament path). The other is the actual length of melt zone and glass transition zones.

Many all metal hot ends do not have good heat breaks and so do not work with PLA as it swells. Hot Ends with PEEK and PTFE have issues with Nylon because those parts can deform at printing temps.

If you decide to replace the makerBot hot end (which I believe may void your warranty) then I suggest looking at reviews in the RepRap and other forums.