Nozzle stuck, nothing comes out  

Re: Nozzle stuck, nothing comes out

Did you preheat the nozzle?

Maybe the knurled drive wheel on the extruder didn't get tightened down and is now slipping?

Were you able to clear it by pushing the accupuncture needle into the nozzle from the bottom?

Re: Nozzle stuck, nothing comes out

Yes I did.

Please I need help. This is super frustrating. I did all that disassembly and assembly. 🙁

Re: Nozzle stuck, nothing comes out

Sorry, I edited my previous post after you read it

Re: Nozzle stuck, nothing comes out

Once the nozzle is heated, have you tried "Load Filament" while simultaneously pushing the filament into the extruder to help it along?

Re: Nozzle stuck, nothing comes out

"Maybe the knurled drive wheel on the extruder didn't get tightened down and is now slipping?"
What's that now? What shall I do?

Were you able to clear it by pushing the accupuncture needle into the nozzle from the bottom?
I was able o push a needle maybe for 2 mm from the bottom. Not anything more than that. But then I thought maybe my needle was too thick(I kinda doubt this). However, I was able to push all the filament out from the top using a 2mm drill bit.

Should I have been able to push a needle from bottom all the way to the top?

EDIT: Yes, I have tried to help it by pushing it down.

Re: Nozzle stuck, nothing comes out

"Maybe the knurled drive wheel on the extruder didn't get tightened down and is now slipping?"
What's that now? What shall I do?

The knurled drive is the brass wheel that drives the filament in to the hotend. The hex screw on that can get loose over time and it will slip on the drive shaft. I have found that the allen provided by Prusa is very low quality, so it does not do a good job to completely tighten the knurled drive wheel. I've had this problem in the past and used a much higher quality allen to tighten it down. Haven't had a problem since.

Should I have been able to push a needle from bottom all the way to the top?

You don't need to use a needle to push all the way to the top. The heated area is only about 10-15mm before it gets past the heatbreak. If you are going to use a needle, then heat up the hotend, unload filament and use it to push up any debris. But I do not recommend pushing more than about 20mm of the needle through.

Hope this helps

Re: Nozzle stuck, nothing comes out

Do I have to disassemble again to fix the knurled drive?

Re: Nozzle stuck, nothing comes out

No, looking from the front of the printer, on the left hand side of the extruder you will see a hexagon window showing the knurled drive wheel. Just turn the wheel and shaft so that you can place an allen in that opening. Make sure you have filament in place and down the the hole to the hotend. This way you can align the center of the wheel to the filament for better alignment.

Re: Nozzle stuck, nothing comes out

I am super unhappy about this printer. One filament change and my nozzle get stuck and broke and now I have to buy a new hotend! Really disappointing.

Re: Nozzle stuck, nothing comes out

I am super unhappy about this printer. One filament change and my nozzle get stuck and broke and now I have to buy a new hotend! Really disappointing.

Better not buying anything new. You still will be disappointed. You are doing things badly wrong. Not knowing where the drive wheel is and how to access it shows you are not a bit familiar with the printer. I really doubt whether the hot end now is correct assembled.
Check on https://www.prusa3d.com/support/
Here is everything you need. Even extruder jam and how to fix it is explained.

Re: Nozzle stuck, nothing comes out

+1 alexander

Re: Nozzle stuck, nothing comes out

I am familiar enough with various 3d printers. You don't have to take that condescending tone with a customer. I simply followed the procedure for changing a filament and the nozzle got stuck!

I can go around and say good things about this printer or bad things about it and your unhelpful comments is not helping my situation!

Re: Nozzle stuck, nothing comes out

I am familiar enough with various 3d printers. You don't have to take that condescending tone with a customer. I simply followed the procedure for changing a filament and the nozzle got stuck!

I can go around and say good things about this printer or bad things about it and your unhelpful comments is not helping my situation!

When I had a clogged nozzle and I tried to clean it out, I found I wasn't able to really clean it thoroughly. This MK2 is my first 3D printer so I am not a big expert, I'm not claiming anything and not judging you, either. I'm just another customer. It is difficult to analyze things via a forum, too!
Anyway, my long term solution was simply to buy several nozzles and replace them every so often.
I'm sure there are cheaper or more get-in-there-and-wrestle-this-to-the-ground ways of doing this, but stuff can get burnt on and with each new nozzle the printer prints beautifully again.

I doubt this is your situation, but here's one more thought: one other thing that might be happening is if this is a used printer, the person before you might have used a higher temp filament than what you are trying now. If you are trying to print PLA, for instance, you can try setting the hot end temp higher (like 255) and then try to run some filament through. And as it goes through dial back the hot end temp to normal PLA temp (like 215) as it comes through. In other words, if you are trying to get PLA through, but that previous person was using ABS, then one has to get the hot end up to ABS temps to melt it and clear it out.

By the way, got tired of it being so darned hard to get a hold of the hot end block to hold it while ratcheting off the nozzle, so I designed a fan cover which can easily swing out of the way. It also means I can leave it swung out and see the hot end as it prints (with filaments where the fan is off). That's half the fun of 3D printing as I'm sure you know. it also directs the fan's exhaust so it blows over the print, but not the nozzle, so it sin't cooling the nozzle. I have the files to print it on Thingiverse here: https://www.thingiverse.com/thing:2239120
With this swinging fan cover, I don't have to remove the fan or front of the extruder to change nozzles. Yay!

Re: Nozzle stuck, nothing comes out

Oh, and I do realize one shouldn't have to replace the nozzle.
But when it can be so aggravating to try to salvage one, I am happier to simply install a new one (and to have spares on hand).

Re: Nozzle stuck, nothing comes out

Again, you probably know all this already, but you were asking for help so here goes…

A couple reputable places to order nozzles:
England: https://e3d-online.com/nozzles-v6-brass
USA: https://www.filastruder.com/collections/e3d-spare-parts-and-accessories/products/e3d-spare-nozzle-v6?variant=755000273

And I also bought an extra couple heat breaks (because I wrecked one when i was very new to this so had to replace it, and wanted to have another on hand for just in case):
England: https://e3d-online.com/v6-heat-break
USA: https://www.filastruder.com/collections/e3d-spare-parts-and-accessories/products/e3d-heat-break-v6

And sometimes the problem is one has to high a setting for retraction, and the hot filament gets pulled up into the cool part of the extruder where it cools, hardens and results in a blockage. Once the heat break and nozzle are removed, the blockage comes out, too. One can then set the retraction lower (to around .8 mm or less) and install a cleared heat beak and nozzle.
I'm pretty sure all this probably is already known to you, but I'm just sharing what little that has helped me in my adventures.

Re: Nozzle stuck, nothing comes out

I'm disappointed too. I can't print with ABS because of a bed thermal runaway. Now my nozzle is clogged too. Cant load filament and can't unload filament. The filament broke off as I tried to pull it to help unload.

How this thing is number one I have no idea