Filament wont go through filament detector

I am very new to 3d printing, and i just got my first printer a couple months ago.

I tried putting new filament into my printer, but it won’t go past the filament detector. I have printed quite a few things before with different filaments and I had no problems. Now I can’t get anything to go past the filament detector.

I’ve tried looking up videos for possible solutions but I haven’t found anything.

I was wondering if anyone had any ideas?

Cut the end of the filament so it has a sharpened tip… sort of like a pencil… this will help prevent it from getting hung up at the filament switch and at the exruder.

i cut it to a sharp point but it wont get past the filament detector. I can see about a 1/2 cm of it in the tube after the detector but it wont go past that point. i’m not certain but i suspect a jam in the detector.

Try blowing it out with compressed air. Not saying that is the solution, just an idea.

Cut filament on a 45 deg angle. Try rotating the filament as you push it through, sometimes filament detectors can be a pain this way.

I have one that requires the filament to be relatively straight, tough for mid to end of rolls. Just have to bend it flat. 2 cents.

while reading and using everybody’s advice i realized that a long piece of plain white filament from my last print had broken of in the tube and due to the color i did not see it creating my “invisible” blockage. I would like to thank everybody who commented for helping me to fix my problem. i never would have figured it out if not for following up on all of your advice. thank you so much.

What is it that Homer says…DOH!

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i have a k1 max and i sympathize, that filament feed system isnt very good;
i bypassed the runout sensor due to those snagging issues;
it works ok ( if you feel you must, you can use a small portion of room temp filament to fool that sensor that it has run out…) ;
if you do this then you will get a message when starting each print that there is no filament, thankfully there is an option to go-ahead-anyway;
if you feed the filament directly into the top of the print head there will be a collar (where the tube used to be) that will be a small irritating snag point but it is manageable

In order to bypass the sensor you can also bridge the pins on the cable, the filament sensor is essentially just a limit switch inside of a plastic housing. So by bridging these pins it tricks the mainboard into thinking that it is permanently closed and therefor has filament in the sensor.

Alternatively if you are using the open source firmware for the K1 Max with klipper you could either disable the runout sensor altogether or add an ‘!’ in front of the pin in the firmware to invert it going from normally open to normally closed.

nice, a hardware OR software “fix” (workaround)

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on my flsun v400 i was having some snagging issues with feeding filament into the runout sensor housing; i got tired of that, bypassed the sensor , feeding filament directly into the print head; i inserted a small piece of filament into the runout sensor and just left it there;
then when the spool is nearly empty, just remove the small piece of filament in the sensor;
in this way i obviously woud have to be there attending thhe printer when the spool is running out, thus i chose to keep the sensor active so i could manipulate it’s function manually