If you let the machine sit and cool down after a failed print, and then try to print again (with no maintenance), does the printer work for a while again?
How hot is the E-motor getting? You should be able to keep your fingers on it.
My brothers and i got this printer Ender 5 plus and have had multiple (25) successful prints to include iron man mask full size thor hammer 17 inch millennium falcon 2 times i have seen a fail like this we are a little new to printing my brother works for NASA and runs a group that uses some big expensive Maker-bot units. so we have his experience. With each machine being different we look to the knowledge of expert users like your self for guidance. This print made it 522 lines out of 1125 then it started printing very thin pics below any thoughts
I'm going to put my money on a clog at the hot end of the bowden tube.
As the X carriage goes back and forth, the bowden tube rotates in the lock fitting on top of the heat exchanger. There are small blades in that fitting to keep the tube from being pushed out, but they cut into the tube and eventually it does back out a little bit. That creates a gap between the nozzle and the end of the bowden tube. Retractions pull molten plastic into the gap and after a while it impedes the filament flow. It continues to work it's way upward into the cool zone and creates a partial obstruction. You get what you got...nice part, everything is moving right along, and then bingo - under-extrusion.
The only real fix for the stock Creality hot end is an all metal hot end. They can still have this problem (same type of lock fitting) but it happens over a much longer time period and you can get through a 24 -30 hour print.
Before I start any long print I pull the tube out of the hot end and cut 3mm off (a nice square cut) and I start with a freshly cleaned nozzle. I found a coat hanger that was the exact diameter of the throat of the hot end and with the nozzle out, and the hot end warm, I shove it through from the top. It almost always pushes a plug of plastic out. Heat creep is a similar problem, but I had altered my hot end cover and installed a nice 4015 fan. Those pneumatic "push-to-lock" fittings that are used to secure the bowden tube were never designed to hold something IN. They were designed to keep something from being pushed OUT. That isn't the same thing. 1) All metal hot end. 2) Preventative maintenance on the hot end every 20 hours of printing and before any long print. 3) Clean the blades of the hot end fan every once in a while as they can pick up loose strings of filament and cooling efficiency will suffer.
1
Hello,
The extruder motor doesn't get hot and it barley gets warm (when it extrudes its cool, and when it stops extruding mid-print its slightly warm, +2 degrees if I had to guess. Not much change in the temp basically), and no I have not printed with abrasive materials (I only print in PLA).
Did you pull the bowden tube out of the hot end and take a look at the end? Is there any black substance around the end? Is the outside diameter chewed up?
I pulled out the Bowden tube and it is clean. No dirt, PLA, or black substances on it, and it's not chewed up. Although, a small part of the end of the tube is a little bit sticky to the touch.
Edited by classifiedI also noticed that this in the bite marks on the filament. It looks like it was turning as it was being fed in.
Does the filament between the nozzle and the extruder gear look "bunched up" like it wasn't going out as fast as it was coming in?
Nope.
When I did an extrusion test by just heating up the nozzle and running the extruder, the filament extruded beautifully. It flowed evenly, quick, and it was thick (the size of the nozzle of course .04 mm) Even when I print a test cube and it extrudes at the beginning, it extrudes well.
This was a cube I printed. As you can see it began fine, then it stopped extruding (hence why it's not completed and the top is all messed up)
This is the same cube, but this time when I printed it, it stopped extruding near the end (at around 90% completion).
This is the exact same cube as printed before, but I printed it again and it stopped extruding at around 63% this time.
Then I manually pushed the filament and it began extruding again.
After I manually pushed the filament to get it started again, I let it run for a few seconds.
The extrusion got very thin mid-print. That isn't the same as stopping altogether.
The E motor doesn't get hot = not a Vref problem or softening of the filament as it goes through the extruder.
A clog at the end of the bowden tube would not clear itself and extrusion would remain poor.
A partial clog in the nozzle got cleared when you pulled the filament. The down side of that is there isn't any preventative maintenance you can do. If it clogs, it clogs. If it would have been the bowden tube blockage there are some things you can do to prevent it, but a clogged nozzle, I don't think there is.
90% of the problems I had with my Ender were from the hot end of the bowden tube clogging. I may have had a nozzle clog once, but I probably blamed it on the hot end and fixing one fixed the other.
It's not a clogged nozzle as I had just changed the nozzle before printing those cubes, so we can rule that out.
Also, I had replaced the whole hotend (Bowden tube and everything) three times already. The first time was because of a thermistor error and I didn't have any extra thermistors at the time so I grabbed my spare hotend and attached it to my printer. Everything worked fine for a while, until this problem occurred. Thinking it was a thermistor issue again (It wasn't), I then replaced that hotend with a brand new one (I had ordered some thermistors but they hadn't arrived yet, which is why I ended up changing out the whole hotend). To check, I disassembled that old hotend to check for clogs (I found none. I then kept that hotened for spare parts). Finally, my new (current) hotend arrived and I decided to replace it with the other hotend (To see if this would fix it and so I could disassemble that hotend and check for clogs or a worn Bowden tube. Surprisingly, There were no clogs, but the Bowden tube was a bit dirty). So I installed my new (current) hotend (which already had a new Bowden tube installed on it) and it still didn't solve the problem.
Then I decided to look at the extruder gears. They are all clear (I cleaned them to ensure no PLA dust was in between the teeth) and they grip the PLA like they're supposed to do. When it stops extruding I see the big extruder gear turning, but I don't feel the PLA being pushed up/further. I don't hear any clicking noises and when I take out the filament to examine it, I find no indications of grinding.
This is why I am stumped.
I will examine my current hotend to make sure there are no clogs internally and I will let you know what I find.
Also, this is when I heat the hotend and only run the extruder motor. As you can see I get good extrusion.
PITA. It was at about this point in my own adventures (3rd stock hot end) that I went with an all metal hot end. It isn't perfect but it's much better.
I went back and read where I was betting on a hot end clog. Right now that bet is looking much better than it was a couple of posts ago.
Ya. It looked good at first, but upon further inspection I found a little disturbance inside. I still have to take it out and make sure there's nothing else. But this is what I found so far.
Other than that everything else is clear and clog free.
Leave the nozzle loose by 1/2 turn. Cut the bowden end exactly square. Shove the bowden in down to the nozzle. Put the lock clip on. Heat up the hot end. Tighten the nozzle the rest of the way so it seals the bowden end. Do an internet search for an all metal hot end.
I did this and it didn't solve my problem. It still stops extruding mid-print.
Also my hotend is all metal. It's a V5 J-Head hotend.
22 hours ago, classified said:Also my hotend is all metal. It's a V5 J-Head hotend.
In this case it's easy - do not print PLA with it. It's not made for PLA.
Warm PLA sticks like crazy to metal. That's why hotends that are suited for PLA do have this PTFE-inliners (well... most of them).
Or do some hardware tweaks, especially if it's not a genuine product. A good all-metal hotend is very well polished on the inside (or even coated). That makes it (kind of) usable with PLA, but also much more expensive.
There are some good points in this old topic of the RepRap forum, or ask your favourite search machine for "all-metal hotend PLA".
https://reprap.org/forum/read.php?1,664823,664891#msg-664891
Hello,
Thank you guys for your help. It is much appreciated. It turns out the problem was not the hotend. It was a misaligned idler bearing in the extruder. I was printing the test cube again when it stopped extruding. So, I decided to disassemble the extruder gearbox to see if that was the problem. It turns out it was. The Idler bearing (that is attached to the trigger, which allows me to manually feed the filament (bypass the gears) and keeps tension on the PLA so the gear grips it) was shifted, causing the plastic part of the trigger to rub against the PLA creating a massive amount of friction and prevented the PLA from moving any further. I completely took apart the gear box and moved the bronze gear on the stepper motor a little further up so the trigger and bearing would sit flush with the bigger extruder gear. I reassembled the gear box and printed the test cube once again. It was a success! My Anycubic Mega X printer works again!
The gear circled in green was the idler bearing that was misaligned due to the trigger/handle it was attached to being misaligned.
Good job picking that up. Trying to diagnose things from far away ain't easy.
(On the other hand, I think we did a fair job of surrounding it. Another month or two and we'd have nailed it down!)
Hello to you all!
Well, it seems my time came.
I own an Alfawise U20 (CR-10 copy) since 2018 and I'm having exactly the same issue as @classified.
No need to say I did the same you did (new bowden, new hotend, new nozzle, new thermistor, new heat resistance, new fans, checked all belts and motors, ...) and the problem remains.
My prints have very good quality until suddenly stop extruding. Already tried diferent/new PLA filament (I only use PLA). I even checked the mainboard and all seems ok and normal.
When I say stop extruding, it really doesn't extrude any filament, no incomplete extrusion or strings. Extruder motor still running, filament seems to be pulled, not slipping on the gear. I already put some washers on the extruder arm spring to push the gear a bit more.
I already asked for help on the facebook Alfawise 3D printers page with no success.
Maybe you could be my salvation!
@GregValiant you seem to be a master user. Any advice/hint?
Thank you in advance!
OK - no pressure!
A couple of questions first.
You have changed out all the usual suspects. If the extruder motor runs too hot, the heat runs up the motor shaft and softens the filament and it doesn't want to push. This is usually caused by the Vref being set too high. That isn't something that just starts up randomly though. The Vref (Reference Voltage) is often adjustable on the mainboard via a small philips head screw next to each stepper driver chip. It is usually about 1volt and measured between the screw head and ground. If it is set too low the motor will run cool but not develop enough torque to work.
If the bowden tube isn't trimmed at exactly 90° then there is a gap between the tube and the back of the nozzle that gets filled with molten plastic which hardens and creates a blockage.
If your retractions are long (over about 6.5mm) then molten plastic gets pulled up towards the heat exchanger and cools into a blockage.
You replaced the hot end fan and it is definitely pushing air at the heat exchanger(?) and then that air can readily escape from the area?
You are having the same problem as I did with my Ender 3 Pro. My second replacement Hot End was an all metal model and finally fixed my problem. The first replacement I tried was a cheap clone of the original cheap Creality hot end (I was pretty sure it would fit). That lead to my development of a new saying "Never be surprised when you clone a piece of crap and end up with another piece of crap."
The "Tune" on these cheap printers is on a knife edge and when they inevitably fall off the edge they can be tough to troubleshoot.
ArunC posted a topic in UltiMaker Cura,
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StudioKubuz 4
mn, weird.
Did you ever printed abrassive materials with it?
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