Do spare throats or a heater blocks ever break?

Question

A question to those who have a 3D printer. Have you ever needed a spare throat or a heater block? Do they ever break?

I just bought some spare parts: heaters, thermistors, nozzles... However, I am not sure if buying throats and heater blocks make any sense.

I've destroyed a heater block because of a seized up stainless steel nozzle once. That ruined the threads for the heat break / nozzle. Haven't needed any spare throats yet. — towe, Mar 02 '20 at 08:48

score 2 · Accepted Answer · edited Jun 18 '20 at 08:29

Short answer

Yes

Long answer

Heater bocks

A heater block is destroyed if one of the following happens

Threads stripped
Bent or otherwise deformed
stripped grub screw

All of these can happen by handling the block with too much force when securing nozzles, thermosensors or heater cartridges.

Throats

Throats can be destroyed, especially e3D v6 throats with their neck down on the center can be simply turned and broken in two. Lined throats can be heated too much and the liner destroyed, which not always can be replaced, mandating a spare part. And you can strip the threads.

Another chance to damage the throat is by using very hard material nozzles - stainless steel comes to mind. Such a nozzle would not deform itself like brass when tightened against the throat and might lead to damage to the end of the throat if exchanged several times.

Conclusion

If you run several printers or change nozzles regularly for whatever reason, it is a very good idea to have at least a complete set of spare parts on hand to fix problems that might occur during work on the printer. I have a fully assembled spare hotend waiting for its day to shine in case my current one breaks...

Just one! ;-) I have spares to build multiple hotends :-) Apart from the Ultimaker 3, those spares cost 150 Euro each... — 0scar, Mar 02 '20 at 10:26
well, I only run 2 printers, and the assembled hotend is an e3D v6... and I have the *spares* from the old tronXY hotend (that runs on an e3d Light6), which is pretty much the one in the Ender-3, so *technically* I have one per printer... — Trish, Mar 02 '20 at 10:46

score 1 · Answer 2 · answered Mar 02 '20 at 10:22

Parts don't have to break or bent, they may become unusable by other issues as well!

In addition to the answer of @Trish, if you clog your hotend, or the hotend/heater block/nozzle gets buried deep into solidified filament (see image below), it might be much easier just to replace the parts rather than salvaging the parts (or you can salvage the parts later, in the meantime you'll be up and running).

E.g. recover from this: