E3D hotend - thoughts?

I just switched from a j-head over to an e3d all metal hotend, and I must say I have mixed opinions. It is a very well engineered hotend, but it does have some issues that I've seen. First off, the plastic fan adapter provided with the kit was completely useless. It was loose to the point where you could just slip it off and if you shook it, it rattled like crazy. The instructions warned to "be careful, it's a tight fit!" but putting on a sock is more difficult. I tried printing one from thingiverse thinking maybe their printer tolerances were off, but the one from thingiverse was exactly the same. I ended up designing one in openscad, based on their design, that allowed me to adjust it for proper fit, and I've since installed the completed hotend on my modified I3. The first thing I noticed was that the fan is LOUD. The next thing I noticed was that it vibrates like crazy which you can feel in the nozzle tip and I'm sure it affects the print quality. If you look at anything that's printed slow at a certain angle under certain lighting, you can see a faint pattern in the perimeter lines. Fortunately, the print quality is still very good, even at the slow speeds the pattern isn't "bad" looking. Another potential issue is there seems to be a larger delay from when the extruder feeds to when plastic actually comes out the nozzle. This has caused issues where permiter lines are started too "late" causing them to be incomplete and causing the first part of it to curl up. This only seems to happen on the first layer on both the "skirt" and the first perimeter. If there are more perimeters, they usually come out fine. I'm printing PLA (at the moment, waiting on more material) and I'm not using a bowden setup, so I don't think filament compression is the issue, then again I'm using a smaller filament diameter now so maybe that's it.. I've got some pretty good prints out of it so far, but it's certainly a different animal than the J-heads I'm used to.

I have an unbranded All Metal hot end that came with my MendelMax 1.5 kit, and I have the same issue about filament being delayed at the start.

i.e it tends to ooze quite a lot as soon as the hot end heats up, which I normally have to remove with a cloth. But then when it starts the print, it can take 10cm of travel (not 10cm of filament) before the extrusion actually starts to come out.

I guess the way around this is to add custom start G code and end G code. I have custom end code that retracts the filament to prevent oozing at the end, but I've not tried to use a custom start code to get the printer to perhaps extrude 1cm of filament distance before it starts the print.

Perhaps other people with All Metal hot ends would like to share their experiences and tips;-)

That's the idea of the skirt function - to get plastic flowing to reach a "full head" by the time the actual job commences. It doesn't really matter if the first part of the skirt track is not laid down as long as the print head is fully primed prior to the main print starting.

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Waitaki 3D Printer

Skirt works most of the time, but not if its a small object e.g only 3cm square, sometimes it doesnt extrude until its actually printing the object :-(

It would be better if it had a min skirt length parameter. (I guess I better get programming and modify Slic3r ;-)

I usually extrude and remove a small amount of filament just before pressing the start button. I only see about a cm delay before extrusion starts on the skirt and no problems on my parts.

You can set the filament to extrude a minimum amount ( say 10 mm) as part of the skirt. That takes care of the ooze issue. Some filaments are more prone to ooze than others (it's not just the hot end).

The fan on mine isn't very loud. I suspect that if you look at yours, it's got a chipped blade. Unfortunately it's a fan size that's not very easy to find.

The fan shroud on mine fits pretty well. I would not call it a force fit. It certainly isn't falling off.

I got mine last friday and am getting better results than with a jhead and no leaks :-) The fan was very noisy so I replaced it with a 40mm fan I had on hand using a housing from thingiverse.

Just ordered mine a couple days ago, any tips/links on which fan shroud worked best? Might print one up early.

I've battled a couple clone jheads with leak issues, hope e3d provides better service.

Stephen

[www.thingiverse.com] with a 40mm fan fits snuggly. Mine has been leak free for 2 days now :-)