I have had my printer for about a year now. After some first tweaking it worked fine. I have printed a lot of parts. But now suddenly I have a lot of problems.
Suddenly one day the filament clogged in the insulator above the nozzle. I bought a new insulator and nozzle. At the first print it happend again!
This time I managed to remove the clogg. Then it happened again! I found out that I could remove the clogg if I put the insulator in my oven at 225C.
Now it has clogged 10 times in a row. I have searched the forum and tried everything I could find.
I have always printed with PLA at 210C. Some said that 195C was enough. So I changed to 195C. Same result…
Could it be something with the nozzle cooling fan?
The fan starts when heating up PLA. But after a while printing it stops.
Should the fan always run? I can’t remember if it always has. If it is maybe this is the problem??
I haven’t found any information about if the fan should blow constantly or not.
I ve tried to set fan to 100% in Repetier host, but it makes no difference.
I really hope that you could take a few minutes and try to help me.
The tube that you have to cut and install into the isolator guide.
Are you sure that you cut it square and at the proper length.
My first one I had to redo 2 or 3 times before I got it.
For my own experience I got the filament stuck in two cases:
Filament over heat
or
retraction too strong.
In the first case the nozzle tip itself is blocked, in the second case I usually found the filament blocked within the PEEK part.
From your description it sounds more like case 2. So it would be interesting if you changed the PLA in the meantime; new spool, new color, or maybe a different supplier.
All these details can impact the optimal settings, so finally you have to check at least your retraction setting.
The settings is 100/100/10.
I have the same filament roll as I have ever had.
The fan doesn’t always run. When I start print and it doesn’t blow I manual start it from the display on the printer. I don’t remember if it used to run all the time.
It’s so frustrating because I haven’t changed anything since it always worked… The computer is the same, the installation is the sam, the filament is the same, the settings is the same. The insulator cloggs although the fan is running!
I haven’t tried to change the retraction speed. But it has always worked before.
Will fix the clogg and the change retreaction and try again.
It finally works! Reduced the retraction to 3mm and increased the retraction speed to 110.
Strangely I haven’t ever changed these values before so I don’t understand why it sudenly didn’t work. Well after the problem solved it’s quite obvious that retraction could cause this problem. But I had never before touched any of these settings. Maybe this should be included in the trouble shooting guide or Q&A. If this happends when retraction i set wrong I guess more people could encounter this problem.
Could you provide what settings you have in Cura?
What works best for you?
This is what I have now. Before I think I had 9 at retraction distance. Now changed to 2. It seems to work a lot better but still som clogging issues.
Printing PLA at 190C.
I’m using retraction 3 mm and speed 140mm/s. Also lower the flow to 75%.
It’s quite hard to clean a clogged nozzle with PLA. PLA leaves a thin coat on the inside wall of the nozzle that will burn when you heat the head to load the filament. That burned coat narrows the diameter of the nozzle causing the next clogging.
its not likely a print setting if this started to happen without changing anything. Here is my theory; after removing and cleaning the nozzle, you reinserted the nozzle in the insulator, but you didnt tighten it exactly as hard as before, and the PTFE tube inside the insulator is no longer in full contact with the nozzle. This happened to me, the tube had shifted upward just a tiny bit. During print, the tiny cavity between the nozzle and the tube will fill with filament and consequently cause jams when its allowed to cool. I removed the PFTE tube from the insulator (not easy, I pried it out with needles) and cut a new one, being very careful the length was correct and the ends perpendicular, and that solved the problem for me.
If the problem is the nozzle, I always use a blow torch and compressed air and/or solvent. Seems to remove any kind of filament residue I ever used.
I like your thoughts.
But when I first got this problem I bought a new nozzle and insulator. After replacing with new parts I got the same problem again! So then it couldn’t have been any residues. Perhaps now after 10-20 times more.
I get a lot of filament clog in the insulator but not that much so it’s any problems removing the tube from the insulator. The tube looks perfekt. Never any problems in the nozzle. Just in the insulator.
When I clean things up and get the printer going again it stops in the middle of a larger flat area (bottom) of a raspberry pi casing. So it doesn’t seem like many retraction’s, should be a good flow of filament.
This problem drives me crazy because the printer have worked perfectly before and now I can’t print anything. I have tried everything I could imagine. Don’t know what to do.
[quote=“JoachimH”]
I get a lot of filament clog in the insulator but not that much so it’s any problems removing the tube from the insulator. The tube looks perfekt. Never any problems in the nozzle. Just in the insulator. [/quote]
Not sure I follow what you’re saying. How could it clog in the insulator? Since there is a teflon tube in there, that could only happen where it touches (or rather: doesnt touch) the nozzle, which is what I described, or at the bowden adapter.
As for ‘the tube looking perfect’, if that refers to the PTFE tube inside the insulator and my theory is correct, there really isnt anything to see, you cant see a gap between the PTFE tube and the nozzle
Either way, what may help, is removing the bowden push adapter, and just ‘manually’ print and retract by inserting filament. It may shed some light on whats going on. I am assuming your extruder is working properly and slipping as a result of a clog. its of course also possible the issue lies with the extruder itself.
Lastly, at the risk of stating the obvious, are you sure you assembled it correctly and didnt, I dont know, forget the PTFE tube inside the insulator? manuals.velleman.eu/article.php?id=15
I have had this kind of problem a few times.
Then I let the fan run all the time while heating the nozzle.
It was down to zero.
Changing the filament from Velleman PLA to Nunus PLA, I had blocked nozzles every time I was not printing longer than 10 Minutes but keep heating since I want to shorten the off time
After I changed to E3D V6, where the fans are on all the time by default (referring to E3D manual)
I have had no issues any more. Not with PLA, PVA and SmartFlex
As I described earlier, the clogging in the nozzle will most likely due to overheating of the filament. Due to the special configuration of the thermal sensor you will increase the temperature of the nozzle when switching on the fan!.
For the clogging in the insulator you have to review the following mechanism:
To get finally a molten filament at the nozzle tip you have to warm up your filament, which takes place along the whole length of the nozzle guide. The filament doesn’t change from solid to liquid in one step but gradually (for PLA the transition starts typically around 70°C). So shortly after the transition between the PEEK insulator and the nozzle guide the filament becomes week. When retracting the material, you pull the filament on the solid side, slightly reducing the diameter of the filament wire (like dragging on a chewing gum). If the filament is pulled too far into the isolator guide, too much pre-melted material will be available in the insulator. This material will fill small gaps between the PTFE tube and nozzle junction. This material will cool down a little bit, generating a blokker for the filament movement. This would not be a major problem, but: now you must press your chewing gum against this resistance. the weak material will blow up like a balloon until is is limited by the PTFE tube sidewalls. If this happens sufficiently far away from the nozzle base, where it is steadily cooled down,no further force will be able to move the filament again, you have the filament stuck in the isolator.
So the retraction width proposed elsewhere in this forum is a good rule of thumb for most PLA materials, however, by the selection of different PLA brands or other materials the thermal characteristics like heat transfer, solidification point, commonly specified as glass transition temperature, will have an impact on the described mechanism, giving more or less space for retraction variation.
From time to time my printer tends to get a clogged printing head. It happens approx. once all 6 months.
Up to now I could always solve the problem.
First 1 try to clear the nozzle with a guitar string and the push pull method.
If this does not help I disassemble the head until I hold the nozzle in my hands. This can be quite tricky because the nozzle can stick quite hard in the heater block. You have to take good care that the nozzle tip is not damaged. But you don’t have to have too much sorrow if the hex nut part gets damaged. Mine does not look really good anymore but it still prints like a charm.
Then I dissolve the plastics stuck in the nozzle with Tetrahydrofuran (PLA) or Acetone (ABS). Next I burn out the rest with a blow torch and put in a guitar string until I can see light through the nozzle if I hold into the sun. And at last I take some soft stranded copper wire and clear all the grime left within the nozzle. (Until you can see no black remains on the copper wire.)
And sometimes I even have to repeat these steps.
yes, I know that.
And because time is money, and it takes ages to realign the nozzles (got 2),
I spent the money on 2 E3D V6 and ever since, I don’t have clocking nozzles.
Even if, I can just unscrew the nozzle without disassembling everything.
up till now I had very few blocked nozzles. It depends also of the PLA used. When I use grey or dark blue velleman fillament I don’t experience problems. However the light green pla from velleman gives me much trouble.
The issue I’m having now is caused by too high print speed. at layer hight 0.2 and print speed 80mm/s(infill) I see the extruder motor struggle (at random times goes back and forth like 7mm) to push the filament fast enough trough the nozzle at 190°C. I found that increasing the nozzle temperature to 205°C relieved the problem. However it remains tricky, and after a few hours I saw my print failed because of clogged nozzle.
Hi I printed my housing connectors, like found on THINGIVERSE, with the light green from Velleman.
There have been no issues with that filament… Temp was 195°C.
Print periods have been several hours each print.
So same filament, but no issues… very strange experiences
