If you're looking for a replacement hot end for a Prusa MK3S printer, then this is exactly what you need. Yes, there are cheap 'knock offs' but I have to say, after years of printing, this has often been a path to frustration.
Naturally this 'hot end' is not a complete extruder. It does NOT include the gear drive system nor the extruder motor, filament sensor and no fans. So it's about 30% of a complete Prusa extruder.
However, as the item description states, the PTFE tube that normally lines the upper hot end is not included in this kit, so you'll need to either use your old one, make your own (Prusa has some very specific tolerances on this, so only do this if you know what you're doing), or buy it separately.
WHEN WOULD YOU NEED A NEW HOT END?
My old hot end developed a fault when I installed a nozzle with a poorly cut thread, leading to poor nozzle alignment and a leaking thread. While I could have simply replaced the heating block... removing the heating element and thermistor proved difficult after several years of industrial use, and I didn't want to risk creating an electrical hazard. So I bought a whole new hot end.
BUILDING THE HOT END:
Firstly, assembling this kit (prior to installation) is straight forward to anyone familiar with a soldering iron and heat shrink. There are YouTube videos that are very helpful. I STRONGLY suggest you ensure that you cut the CORRECT end of the supplied thermistor (thermometer) cable to avoid frustration. There are no instructions included, so you should compare the plugs from your previous thermistor. Total time, including the attachment of the cable, and assembling the remaining parts is about 5-10 mins.
ACTUAL INSTALLATION:
Now thankfully, Prusa's MK3S is relatively straight-forward to swap hot ends. I'm just glad it didn't require a complete tear-down of the extruder unit that took me 3-4 hours to build during the original assembly of the printer kit. I think I took out a total of 6 screws on the extruder, cut two cable ties at the back of the extruder, undid two more screws on the control board box, and unwrapped the extruder cable wrapping, as instructed from the assembly book/Prusa site.
It sounds involved, but if you're careful and pay attention to details, then you'll be fine. However, if you bought a pre-assembled Prusa printer, this may seem challenging.
You'll find that you have a surplus of cable, but I just routed the excess around the inside of the box before plugging it in. Total time for the installation, about 55 minutes.
SO HOW'S IT GOING SO FAR?
It's good to start with a whole new hot end, the first few prints so far have come out beautifully. Although with the current Canberra winter, even an enclosure can only do so much to deal with environmental 'issues', but I'm not getting any leaking 'blobs' and I haven't had a single click from my extruder since the the installation Overall I'm happy with this unit. :-)
Unfortunately, I didn't take any photos and my phone was left at my in-laws place some 600Kms away, so I don't have any pics to share, but I hope the detail here has been helpful.
All the best in your 3D printing!
