Chirpy's Cheapy Hotend by cae2100

Last crawled date: 2 years, 12 months ago

Im sorry or all of the reading, but here's my hotend.
My hotend is built from a piece of oak dowel rod that I had laying around, a 3mm OD, 2mm ID ptfe tube that I got on ebay for really cheap, a piece of a heatsink from a power supply (solid aluminum block), a 1 inch piece of a 6mm bolt with a 3mm hole drilled through it, and a welding MIG tip. Most of this can be found in your garage, the trash, or at walmart, lol. The rest of what you need is just generic hotend parts from wherever you normally get them.
As Ive shown in the drawings, the thermal break is 32mm long with a 2mm hole drilled longways through it. Then drill a hole 3mm though it till 3mm from the end, and a 5mm hole 14mm into the piece of wood so it matches the drawing above, then just use a drill bit and turn it with your fingers to taper off the top. I then used my 1/4th inch hole cleaner tool, but you can just use a 1/4th inch or 6mm die to cut threads into the dowel rod so it fits in well.
The heater block is just a 10mmx20mmx16.5mm aluminum block that was cut from the heatsink with a 6mm hole drilled through the side/end for the heater element, a threaded m6 or 1/4th inch hole, and a 3mm hole, threaded for a screw in thermistor, but you can just put the thermistor in the hole instead.
The metal tube that connects the heater block and everything together, that's just a 1/4th inch(6mm) stainless steel bolt that I cut off the head so it's just a hollow bolt with a 3mm 1/8th inch hole through the middle of it. It's around a 1 inch (25.4mm) long. I also put a simple washer and a nut on the bolt, then screwed it in so it locked everything tight against the thermal break(oak piece)
The tip is threaded and the original threads of the MIG tip is cut off, the threads of the tip will go 5mm(half way into the heater block) and stick out around 7.5mm, just use a hammer and file to smooth down the nozzle like you see in wildseyed's hotend. I drilled mine 2mm till almost 1mm from the end of the tip, almost to the very tip of the nozzle. Then I drilled 3mm into around 2mm from the opening so it goes from 3mm hole, to 2mm hole, then the end of the nozzle.
Lastly, you need to run the 3mm OD, 2mm ID ptfe tubing as far as it will go into the hollow bolt and thermal break, then cut it off a hair over 2mm from the end of the bolt so it overhangs just slightly. This is so that when you put it together, it'll self seal itself up and wont leak.
I put the nozzle in first and tightened it up, then put the bolt attached inside of the oak rod in, and tighten it up, it'll seal it up. Just use some PTFE plumbers tape on the threads going into the heater block so you never have to worry about any leaks.
Ive only used this hotend with PLA, and it works perfectly with that, but I cant see any issues why it wouldnt work with ABS also.
Ive been using this hotend on my homemade prusa i2, and it's performed perfectly since it's been built. Before anyone asks about max temps and such, truth is, Im not sure what it would be but probably is around 240s or so due to the ptfe in it.
EDIT: here's a video of the printer running with the hotend:https://www.youtube.com/watch?v=c5UHJzLdNJk