Need some community guidance about FDM extruders.
What extruders have you used and what are your results/experiences/reliability with different filament types for long print times jobs (+5h)?
I’m going to go ahead and assume you mean hot-ends, because in general all extruders operate on the same principle and they aren’t really more or less reliable than their brethren.
J-head, 3mm and 1.75mm filament, everything from the MK-IVB up to the most recent iteration. 2 of the heads have had more than 3 spools through them without ever so much as a hiccup, the other one, the MK-IVB, the one on my machine, is 3mm, 0.5mm nozzle, and has had over 12 spools of filament through it, never needing cleaning. I’ve tested my nozzle at 146mm/s reliably.
All of these hot ends have used both PLA and ABS without issue at all.
Every makergear hot end I have ever had jams on me. I just cannot for the life of me get them to extrude for crap without clogging.
The Budaschnozzle (3mm, 0.5 nozzle) has also had many many many spools of PLA run through it without any problem either, except for the old design having the threaded PEEK snap once, and having to upgrade it to the “1.1” design. The Budaschnozzle is the fastest I’ve used, but being on an old i2 Prusa I cannot get up to the speeds needed to give it justice.
I have a lot of this experience because of my hackerspace. We have many 3D printers, most of them Prusa i2s, but also a Makergear Prusa, Sells Mendel, Cupcake, 2 Ultimakers, and more. I take care of the machines that people leave at the lab so that others may use them.
@ThantiK
Thank you I really meant the filament feeder, but thanKs for sharing. The pursuit of reliability entails having a good hot end too.
Have had a look and the MK-IVB looks like an impressive piece of kit.
Yeah, largely filament extruders don’t matter much. The hot end typically determines if they work or not. There’s really either work, or not work…not really any performance difference between them from my experiences. Printing 5h stretches, or 5 minute, or 100 hour stretches – a filament drive just isn’t going to perform any differently.
I’ve used the earlier RepRapFab-hotends and had a couple of problems with them:
-The thermistor was only glued (high-temp silicone) into a blind hole and started falling out after a couple of kilos.
- The PTFE tube started bending and blocking the filament
- The heater resistor burned up once (which was probably my fault)
However, it’s compact and heats up quickly. It also has very little lag and ooze.
I then tried the Budaschnozzle (v1.1, 3mm, 0.5 and 0.35mm nozzle) and was (and still am) very happy with it. The 'schnozzles are all still standing strong (except the bottom wood plate on one, which is not needed anyways). They can take high speeds and are very robust, but they lag and ooze a bit more than the RRF hotend. The schnozzle also takes a bit longer to heat up, but that makes temperature control easier once it is up to operating temperatures. It’s physical dimensions are a problem on some printers - i had to design a custom x-carriage to fit it on my printer. But still, i value reliability and printing results a lot more than the one-time effort to properly mount it and therefore can only recommend it.
For long-time prints, neither of the two hotends showed any issues (except the RRF completely failing in the middle of a print once). I can attest that the schnozzle works well for PLA and ABS. I have not tried the RRF one with PLA.
As for actual extruders (“cold ends”), the Wade’s/Greg’s design is all I’ve used. With a good hobbed bolt (M5 around stainless), a strong motor and enough spring tension, they work without any hiccups at all - i feel no need to try other designs 
If can confirm @ThantiK observations on the J-Head and Makergear hot-ends. I had continual problems with jamming and the Makergear, but after switching to a j-head it has been smooth sailing in that department.
The Makergear filament drive seems pretty solid and the only time it’s slipped is when I had a filament freeze-up due to a heater connection coming loose. My only complaint is that loading it could be less hassle.
@Jason_Gullickson the birdstruder (http://www.thingiverse.com/thing:13628) is a good replacement for the MakerGear mount.
The MK6(+) is crap. Both the filament drive (delrin plunger, no spring) ,the hotend (no thermal barrier at all) and the nozzle (too flat, PTFE coating rubs off).
The BfB hotend is a nightmare to assemble and very bulky but their huge drivescrew filament drive is strong as hell due to the large contact area between filament and screw.
Looking for a replacement hot-end compatible with ToM after I already replaced the extruder.
The current @Ultimaker combo of hotend v2 and extruder with v3 bolt and new extruder clamp (as shipped by them currently with all printers) works like a charm. I’m doing 24 hours+ prints all the time.
I’m posting one example of this and the implications (running out of filament :D) in a second!
@Florian_Horsch_flouS @ThantiK
+Ultimaker combo of hotend v2 and extruder with v3 bolt works like a charm for PLA/ABS really great performance since I moved to these.
But:
I am having loads of trouble extruding LAYWOO-D3, as it strips. I am thinking about doing something about it, still do not know what hence the need for experiences/ideas.
Hm… I printed it very well. What’s your problem with it? Filament is eaten up, or does the hole filament break (due to humidity?)
I’ve had my best reliability with a Wade’s using a nicely hobbed bolt. It’s a good mix of torque and speed, and while it’s large it’s very easy to adjust tension.
I’ve used some direct drive extruders as well - Airtripper’s Bowden works well using an 8mm gear. Avoid direct drive extruders with no support for the motor shaft.
@Florian_Horsch_flouS
It is curious you say that, I am experiencing random filament strip on the bolt see: