Air Prints

[amigaman]

I am getting air prints on 90% of all of my prints now. It prints the Raft then nothing. What could be going on?

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[chengl03]

I may not be the best help, but maybe with some more info of what is going on, others may be of help. What filament? Nozzle temp? Default setting or if not, what did you change or add? Did this just happen or has the same thing occur on all the prints so far? Any weird noises coming from the machine that is out of the ordinary? These are just some question that I have come up with from past experience from my printing problems.

[firesped]

hard to say without more information. If your extruder is stock, likely it is not grabbing completely onto the filament you are using and it is causing a pressure build up in the hotend.

The first question is, is your filament grinding at the gear?

[amigaman]

The Filament is not grinding. Its HICTOP PLA.
Everything is stock on the printer.
Printing at 205 degrees.

[zemlin]

Could also be a partial clog. Would be worth trying another nozzle.

[amigaman]

Could also be a partial clog. Would be worth trying another nozzle.

Don't understand why the clog would happen after the raft and not before?

[Michael.P@Raise3D]

The reason for the part failing after the raft is because the filament is being extruded at a high speed and when you exit the raft phase the next layers are slower allowing for heat to creep up the filament and premelt it in the barrel. Check your temp settings and make sure you are within spec on the filament, from there you may want to check the fans and see if they are blocked or reversed (open side of the fan faces out). Knowing the rest of the settings will help us diagnose it.

[amigaman]

The reason for the part failing after the raft is because the filament is being extruded at a high speed and when you exit the raft phase the next layers are slower allowing for heat to creep up the filament and premelt it in the barrel. Check your temp settings and make sure you are within spec on the filament, from there you may want to check the fans and see if they are blocked or reversed (open side of the fan faces out). Knowing the rest of the settings will help us diagnose it.

Fans are working as they should (I have not changed their directions). Printing at 205 - Box states 190 to 220.

What would you suggest I change?

[zemlin]

Could also be a partial clog. Would be worth trying another nozzle.

Don't understand why the clog would happen after the raft and not before?

It wouldn't be a clog happening after the raft, but a nozzle that's partially clogged that allows the printer to work but increases the back pressure in the extruder. Over time, perhaps with heating of the machine, it can no longer push out the material.

I fought an issue like this earlier this year. Prints appeared to be starting fine but would then give up. Scrapped a lot of parts before trying a different hot-end and the issue cleared up. Further testing isolated the critical component to the nozzle.

[Mecha_Monster]

Most probably you have burned debris inside of the extruder. You can try to clean it with fire, but its easier to just replace the nozzle and be sure that the inner tubes are clean.

[Vicky@Raise3D]

Have you ever tried with hand pushing the filament when there is no extruding? Can it continue or totally stuck?
And want to ask a close picture of the whole hotend.

[amigaman]

Have you ever tried with hand pushing the filament when there is no extruding? Can it continue or totally stuck?
And want to ask a close picture of the whole hotend.

There seems to be space in the extruder after I find the print failing. i am able to push the filament down and it does come out the tip.

[Michael.P@Raise3D]

When running the "Extrude" command, can you pull up on the filament gently and get it to bypass the feed motion?

[amigaman]

When running the "Extrude" command, can you pull up on the filament gently and get it to bypass the feed motion?

I cannot pull against the loading Filament.

Here is a picture of the filament I removed from extruder after a failed print:

[Vicky@Raise3D]

Would you like to take the hotend apart and check whether there has any stuck inside?
BTW, your heat sink seems a little too close to the heating components. I will recommend to move it higher.

Attached instruction video:
https://www.youtube.com/watch?v=Q3EaDHNdlKU
https://www.youtube.com/watch?v=hobwePlokQc

Note: Please follow the steps in video carefully. Do not apply any force to throat tube, or you may break it. If you feel any resistance, heat the component to soften the stuck filament inside first.

[amigaman]

i cleaned out what I think was a clog. Printed for about 20 hours then back to the same issue. Checked for Glog again and sure enough another issue.

What is clogging my hot end?

I moved the heat sink as recommended.

[Rogman]

I agree with Zemlin and Mecha_monster, I think you need to replace the nozzle. just my 2 cents

[amigaman]

I agree with Zemlin and Mecha_monster, I think you need to replace the nozzle. just my 2 cents

I screwed a new nozzle on when I cleaned the extruder. But if the Nozzle works for the raft why would it quit working for the build?

[Mecha_Monster]

Well, for the raft the flow rate is greater than for the model. Also, if you look close to your pictures, your raft is inconsistent and faulty; it is not extruding all the amount of material it should (that's why you have detached strings and uncover sections). Immediately after the raft, before printing the model, you have a non-extrusion/retraction command, which makes more obvious your flow problem.

[Rogman]

the raft extrudes at a different rate, it is shoving out a thicker diameter of filament at the beginning so a lot more pressure, also check that you haven't scratched up the throat tube while cleaning, that could also lead to problem. i am a firm believer of insulating the hotend to prevent radiant heat downward towards PLA. The extra heat makes PLA curl. insulating the hot end will also prevent the upward radiant heat. you might have heat creep over time creeping up you throat tube causing the PLA to soften (reach glass transition temp) to early. try printing at 190c and see if any better.