Extruder Gears Slipping; Hotend Bent ?
I set a print to go over night using the white filament that came with the printer. At some point during the print the filament clogged and the print eventually failed. Now I keep getting gear slippage and terrible print quality with eventual failure after a couple layers. I have cleaned the nozzle and extruder gears thoroughly and it has not fixed the problem. When performing these activities I noticed that the hotend and nozzle are now at strange angle (see picture). I'm guessing that this might have something to do with the problem, but am not sure how it happened and how to fix it. My working theory is that the nozzle clogged and that repeated attempts to extrude filament created a backup of filament in the hotend that eventually bent the apparatus. How would I go about unbending it?
Re: Extruder Gears Slipping; Hotend Bent ?
If you want to know for sure if it's bent, you could go ahead and disassemble the entire extruder assembly (gasp) to get to the hotend. It's a pain to do as you kinda have to unwrap the cable wrap at the EINSY because of slack that might develop and it's kinda really involved. If you do get it all apart, you can take the e3d v6 hotend in the reverse of these instructions:
https://wiki.e3d-online.com/E3D-v6_Assembly
Just preheat it to take out the nozzle (to like 150-200) so you don't damage the nozzle.
I've never had a jam bend something in the hotend before. But if something curled up I could defiantly see that as a possibility - it's in there pretty firm, unlike some other printers, and the "heatbreak" (the part most likely to bend) is pretty thin-walled.
Maybe one of your plastic parts are damaged instead?
Re: Extruder Gears Slipping; Hotend Bent ?
It Kind of looks bent but it's hard to see / judge.
Could you open the "door" on the extruder (that thing -> http://manual.prusa3d.com/Guide/5.+E-axis+assembly/510?lang=en#s8192 )
And have a look at how far out the PTFE Tube is?
Re: Extruder Gears Slipping; Hotend Bent ?
Tubing is only out 2 to 3 mm. I know it is kind of hard to see, but unless the hotend is supposed to not be perpendicular to the heat-sink I think it be bent...I'll disassemble and let you know what I see. I'm thinking that the heatbreak being heatbroke is not outside of the world of possibility.
Re: Extruder Gears Slipping; Hotend Bent ?
I also had disassemble my hotend lately (had a nasty clog). I did hot had to remove all the cabeling. My cables had enough slack to get it out my just unscrewing the fand and the fron cover. Just be careful with the hotend wires.
PS: I broke my filament sensor / or the filament sensor cable during the process. 
Re: Extruder Gears Slipping; Hotend Bent ?
Okay, well I got it all taken apart now. Thanks for the disassembly links. So, my conclusion is that the heatbreak is definitely bent. However, now I have some questions if anyone would oblige:
a) My cursory attempts to bend it back didn't really work. I tried pliers and even sticking a thin Allen key down the middle. I think that I'll probably have to use vice grips to get enough leverage to correct the bend which will also screw the threads up to the point of scrapping regardless. Any ideas here or do y'all agree that I should just get a new heatbreak?
b) Removing the heatbreak and heatsink from the extruder housing is difficult and it does not seem to want to slide in/out as the assembly instructions show. I also can't seem to remove the tubing or disconnect the heatbreak from the heatsink. Perhaps I should just use vice grips to remove/scrap the heatbreak?
c) A replacement E3D heatbreak is available online from the European distro, but I would prefer to purchase from Amazon. Of course, with any 3D printing accessories there are a wide variety of options out there. What is the value of purchasing a "Genuine" heatbreak considering the ease at which the stock one broke?
E3D Euro Distribution Site: £11.50
https://e3d-online.com/v6-heat-break
"Genuine" E3D V6 heatbreak from Quantum 3D: $21.99
https://www.amazon.com/dp/B077Y2MHW8
"Genuine" E3D V6 titanium heatbreak from E3D: $49.99
https://www.amazon.com/dp/B07B693GG6
A slough of inexpensive aftermarket replacement hotend part supposedly compatible with the E3D V6 hotend:
https://www.amazon.com/dp/B074NX68MP
https://www.amazon.com/dp/B07BLKG4XW
https://www.amazon.com/dp/B07B2PHY36
https://www.amazon.com/dp/B06XBXDJY3
https://www.amazon.com/dp/B075NKFZWR
Re: Extruder Gears Slipping; Hotend Bent ?
Unfortunately, this is a modified E3D heat break, only available from Prusa Research.
Although you may find that the regular E3D heat break will work better for you. Have a look at the E3D web site, there is a list of official resellers there. https://e3d-online.com/resellers
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Extruder Gears Slipping; Hotend Bent ?
Although you may find that the regular E3D heat break will work better for you
Im running the E3D original hotend on my MK2.5. Cant say that i have noticed any difference.
---
Gert
Re: Extruder Gears Slipping; Hotend Bent ?
What is modified on the Prusa E3D heat break from the stock one?
One of the REASONS I bought the MK3 was because it used a E3D V6 extruder assembly....WOW, yet another Prusa curve ball!!!
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http://www.youtube.com/channel/UC5djrxBeeOKB9_6rHnn6G8A
Re: Extruder Gears Slipping; Hotend Bent ?
It's well documented on the forums - particularly in the Mk2/s+MMU section.
The upper hole is drilled at 2.1mm instead of 2mm now denoted by the red band in the break section (but earlier modified heat breaks did not have the red band).
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Extruder Gears Slipping; Hotend Bent ?
a) My cursory attempts to bend it back didn't really work. I tried pliers and even sticking a thin Allen key down the middle. I think that I'll probably have to use vice grips to get enough leverage to correct the bend which will also screw the threads up to the point of scrapping regardless. Any ideas here or do y'all agree that I should just get a new heatbreak?
b) Removing the heatbreak and heatsink from the extruder housing is difficult and it does not seem to want to slide in/out as the assembly instructions show. I also can't seem to remove the tubing or disconnect the heatbreak from the heatsink. Perhaps I should just use vice grips to remove/scrap the heatbreak?
c) A replacement E3D heatbreak is available online from the European distro, but I would prefer to purchase from Amazon. Of course, with any 3D printing accessories there are a wide variety of options out there. What is the value of purchasing a "Genuine" heatbreak considering the ease at which the stock one broke?
E3D Euro Distribution Site: £11.50
https://e3d-online.com/v6-heat-break
"Genuine" E3D V6 heatbreak from Quantum 3D: $21.99
https://www.amazon.com/dp/B077Y2MHW8
"Genuine" E3D V6 titanium heatbreak from E3D: $49.99
https://www.amazon.com/dp/B07B693GG6
A slough of inexpensive aftermarket replacement hotend part supposedly compatible with the E3D V6 hotend:
https://www.amazon.com/dp/B074NX68MP
https://www.amazon.com/dp/B07BLKG4XW
https://www.amazon.com/dp/B07B2PHY36
https://www.amazon.com/dp/B06XBXDJY3
https://www.amazon.com/dp/B075NKFZWR
DO NOT BUY THE CHEAP HEAT BREAKS. Every one you listed, are JUNK.
The Titanium would be a good upgrade. I would like one myself, however they are just so expensive. They really would only help printing ABOVE 260c. (Titanium does not conduct heat like most metals, so it's a *VERY* good heat-break)
I would like to point out a "off brand" one on amazon. "Micro Swiss Thermal Tube E3D V6 1.75"
I do not know of any advantages to the "offical" Prusa one.
I would say there's nothing wrong with the one you linked from Quantum 3D.
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Re: Extruder Gears Slipping; Hotend Bent ?
Well, Prusa customer support got back to me and I got a whole new hotend! Now I just need to install it. I can't seem to pry the old hotend out of the plastic casing. It wiggles around but does not seem to slip out easily. Any advice? Thanks!
Re: Extruder Gears Slipping; Hotend Bent ?
Check this video from Shane: