I started in 3d printing or reprap as it's known with a purpose built hot end. It was the cause of many knightmares over the course of building the printer and getting some quality out of it. I resolved to replace it. Many commercially made ones are very expensive and people will get quite caught up in getting the latest model in the usually vain hope of improving their machines quality and capabilities with it. This is folly!
Hot end are really very simple devices and the basic parts are cheap and readily available. I'm using exactly this set up and it's cured the vast majority of problems I had with my machine.
I've tried to give a few basic guidelines and explain the purpose of the mysterious entity that is a hot end.
For this you will require:
1 Aluminium heating block
1 brass nozzle (sharp pointed)
2 26mm M6 'throats' (appropriate to your desired filament size)
1 small square of automotive heat shield (ask at your local repair centre for offcuts)
5 M6 washers about 4mm wide
6 M6 Repair washers about 20mm wide
3 Tee Nuts (see the vid for an explanation) or 2 M6 stud connectors
1 M6 Pnuematic push fit tube connector (for a Bowden Tube). This is optional depending on your extruder setup.
A small length of PTFE tube liner (appropriate to your chosen filament size and throat diameter. Again, see the vid for an explanation)
PTFE Plumbers/Gas fitters tape
1 Heating cartridge/resistor
Here's how to put them together.