[Gulfcoast Robotics] All Metal V6 Bowden Extruder Hotend for 3D Printer - 24V /1.75mm Filament / 0.4mm Nozzle.

Update:Initially I was a little unhappy that I had so much clogging with this hotend and took it off my printer. Then I found some PTFE lined heatbreaks from another seller here on Amazon. I tried them with this hotend and my clogging problem was solved. The heatbreak I substituted for the one that came with this hotend is nothing fancy except that it has a short section of PTFE that starts at the end that butts up to the nozzle in the heat block and extends up maybe half way into the heatbreak. I imagine that it probably goes all the way to where the bowden tube stops or something like that. With PLA on my little printer it works great and the heater on this hotend is much more powerful. It heats faster and holds temp extremely well. I did a PID calibration immediately after installing this on my printer and I strongly recommend others do the same. Anyway, although its not "all metal" it works and its much better than my stock hotend. I gave another star just for the heck of it. My next experiment with this will be PETG. We'll see how that works.Original review:So a bit of backstory... My older Monoprice MP IIIP Mini was struggling to maintain 200C when printing with PLA. I wasn't sure if it was the thermistor, the heater cartridge or both so rather than replace just those parts I decided to upgrade to a full (not Lite) E3D V6 clone. I wasn't going to spend $60 on a real one since I only paid $60 for the whole printer. Also, I wasn't having much luck finding nozzles for my stock hotend since is used a partial PTFE liner between the heatbreak and the nozzle so the nozzles had to have an ID large enough to fit the PTFE liner. I thought this was causing me some other print quality issues so again, replacing the whole hotend with this Gulf Coast clone should do the trick right? Well, not really. After changing out the hotend with the new one I started having clogs. Not real bad ones but enough to fail the print mid-way. I played with retraction settings and heatsink fan placement and tuned my PID and still no luck. I would get clogs with retraction turned off in Cura so I knew it was not that. I had read warnings about the roughness of the finish of the Gulf Coast clone heatbreaks and just wanted to see for myself. I honestly can't say for sure that is the problem but I'm not going to try and cook out all the melted PLA out of the all metal heatbreak to find out what the finish is. I decided that keeping the heater block, the thermistor and the 40W heater cartridge in place should be fine and swapped my old heatbreak (the PTFE lined one) and heatsink back in to the hotend. Problem solved. Also, the new heater cartridge performs much better than the Monoprice stock heater (probably a 25W cartridge based on the slow, unstable heating). I'm only giving 3 stars since it is apparent that for me to make their product work I would have to but a $20 polished titanium heatbreak and that is just BS.So, there it is. I should have listened but didn't.

I installed this on my Ender 3 a few days ago and I've been very happy with it. I do recommend splicing the wires and using heatshrink at the hotend and not running them through the stock cable tube like I did... it was a pain. I printed the Petsfang E3D mount off of Thingiverse and it is much nicer to look at than the stock hotend setup. I cut reliefs for the holes on the silicone sock so that it can be put on and off without having to remove the heater cartridge and thermistor. Before I installed this I took it apart and watched the E3D assembly video just to make sure that it was assembled tightly and I haven't had any issues with it so far. The print quality has been great and I've been slowly dialing my retraction settings back! I bought another one of these for a custom build and I'm excited to put it to work! If it smells a little odd at first it will go away... probably just some residual oil.___---Update 9/11/19---___ It wasn't long before I began having issues with PLA jamming within 10 minutes of a print. I ordered the titanium throats from 3D Passion and installed it applying thermal paste on the threads for the heat sync side (for much better cooling) and I have not had a single issue since, even when I went up to 6mm retraction (which is way to high). Hard to say what fixed it between the thermal paste and the new throats since I installed them at the same time, either way it was still cheaper than purchasing a genuine E3D and my performance out of this hotend has been indistinguishable from one. I'm getting no stringing with 2mm of retraction at 70mm/s on my Ender 3. I'm still pleased with this hotend!

Edit:Things are even more weird now. I've checked the thermistor output using a multimeter and got basically the output that thermistortemps in Marlin firmware indicated for the tempurature shown on my machine. So then I bought a tempurature indicator from Amazon (Proster Digital Thermocouple). Now things are strange. I've been trying to get a correct reading but the indicator I bought didn't even tell me what thermistors came with the package. So I guessed and I'm getting weird results. After about 250C (311C on the indicator) temps get whacky, I can increase and nothing happens. It looks like I can print PETG because I didn't want PLA in the head as I moved to higher temps and PETG moves well at 311, but nothing there maps well. I don't know if what I'm working on will make a difference. I'm going to buy an E3d and compare.Turned on the machine to heat and tighten the throat to the block and found it was -27C, system faulted of course for a runaway and so I checked the thermistor with a multimeter. The hotend I was replacing this with (this is 24v and the other was 12v) showed 100k resistance and this showed 60k.I'm not an electrical engineer so the title may be wrong but, the results are pretty clear, had to change the thermistor for this to work properly.Everything else is fine.