Filament blockage in new heater block?

Razai

https://www.ebay.com/itm/JGAURORA-3D-Printer-Hotend-Assembly-Nozzle-Throat-with-Heated-Block-for-A5S-A5/202885546860?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

Folks, I bought this and installed it tonight in my A5S. Everything seems correct, but when I load the filament it gets stopped somewhere in the new parts (Threaded "stem", heated block). When I unload the filament, the end of the line is completely clean and cool. I can't imagine what is causing the blockage. Any thoughts? I've changed out the nozzle just to make sure it wasn't nozzle-related, but..?
Thanks

Stephen Todd

I've not had the problem, but others have said it is caused by having a gap between the white plastic PTFE inner tube and the metal screw-in tube - maybe your tube is not screwed in far enough - or the PTFE tube is not all the way down

Is it a new tube? If an old tube, it may be distorted

Razai

All parts are new. I have seated everything as tightly as possible. I think it must be related to that area, though, as the filament is not being heated.
I wanted to manually feed the filament through the works and guide it into the proper channels, but the A5S won’t feed unless the hot end is heated. I just can’t figure out where or why the filament is binding.

Stephen Todd

Have you done a pull? - Where you unplug the bowden tube from the top of the heat break, heat the hot end to about 220c, then manually push in a length of filament till it melts, and hopefully oozes out of the nozzle - then pull it out quickly - it sometimes pulls out a piece of baked filament - but you have to do it manually and quickly

You also need to cut the filament at a 45 degree angle and not flat

When I fit a new reel of filament, I cut the end sharp and manually feed it into the hot end until it oozes out of the nozzle after unplugging the bowden tube so I can get hold of the filament - it does take a bit of effort to get the filament through - and you have to press the feed motor filament release lever at the same time

I find the automatic filament feeding method very hit and miss

Razai

I will try that. I wasn’t aware of the button that can be depressed to allow me to manually feed the line in.

Razai

Using the manual method, I was able to get it to feed. Now the problem is that the new heater block assembly is resting far too close to the bed surface. It smashes it down to the point that I can’t adjust it. It’s the same length, and same parts as what I had before, so I don’t understand why there seems to be this leveling issue.

Samuel Pinches

Welcome @Razai - You may want to adjust your z-endstop? The white block with the microswitch, inside the right column. You can move it up to raise the z-home nozzle position.

Razai

I appreciate all of the feedback.
I have become fairly comfortable with this machine by now. I solved the Z issues. However, the original problems have worsened. Feeding the filament still baffles me. In over 1,000 hours of nearly continual use, I have never needed to manually feed in the line. There seems to be an alignment issue with the new heater block/threaded sleeve causing the blockage. Late last night, I finally got everything reassembled  only to have melted filament leak from the top of the heater block where the threaded sleeve attaches. I have never seen a leak at that point before. That suggests that the blockage is severe enough to force the melted filament to find an exit other than the hole in the tip of the nozzle. 

At this point, I am actually shopping for a new A5S. I can’t afford to be down for this long, and I can’t figure out these issues.
Dozens of rolls of filament have loaded effortlessly into this machine. 

All of these problems started with the replaced hot end parts.

I replaced the parts due to major leakage issues at the nozzle of the old parts.

I know printers have a shelf life, but I feel that I ought to be able to keep this one running. I gave up on Creality machines because after 5-7 great prints it was impossible (for me) to keep them running. I have found the A5S to be the best machine I have yet owned, but this has me stumped.

Samuel Pinches

Hi @Razai , yes these issues are frustrating for sure. Regarding that leak, the nozzle should be tight against the heat break in the heater block thread - that leak suggests maybe check that? The nozzle should not be tight against the heater block itself.

Razai

I do have that bap between the nozzle and the block itself, but the filament isn’t even reaching the nozzle. It is somehow blocked and forced backwards where it seeps out on top of the block around the threads. The thing is, there is no obvious blockage anywhere. When it is all apart, I can see through everything. It’s clear. Once assembled, the filament is
blocked.

Samuel Pinches

I'm sorry @Razai - that is confusing and doesn't make sense. Try heating to 240C and pushing some filament through by hand to try to get things through. If you disconnect the bowden tube at the print head, you could try an "atomic pull".

https://support.3dverkstan.se/article/10-the

Stephen Todd

All I can add to this is that the parts you purchased are either defective, or you are assembling them incorrectly

At this stage I would be shopping for an alternative hot end assembly - preferably pre-assembled

Razai

The hot end came assembled. I bought another, and it should arrive today. What I will do differently this time, I really don’t know. 

Samuel Pinches

I would suggest to inspect it before installing and check that the nozzle is tight against the heat-break (not against heater block) before reinstalling.

Stephen Todd

Maybe watch this?

Razai

That is the video I watched before the install. It’s helpful. I am sure there was an alignment issue with the parts. The new parts have not yet arrived, but I am hoping the same issues don’t repeat themselves.

Stephen Todd

I have seen photos of white thread compound applied to the screw in thread of the metal tube - presumably to stop filament leaking

Not sure what the white stuff was - possibly high temperature liquid gasket compound meant for cars and motorcycles - I have some sealing my carburettor to the engine block on my motorcycle  - works great, no air leaks