Filament keeps sticking to the nozzle

I'm quite new to 3D printing and don't know all that much about it. I recently bought the Robo R1 and had some mixed experiences with it. Some prints worked great, others just wouldn't work.

Today I was looking for a possible problem that caused my prints to fail. I noticed that when my filament extrudes from the nozzle it tends to stick to it, creating a loop. This happens every time, even if I remove all the left over material from the nozzle. I'm not sure if it supposed to do this, but I think this might be causing my problems.

A picture of the situation:



I hope someone can help me with this.

 

Looks like your firmament is not retracting. Check you settings in your software.

 

I don't think that is the problem. In this photo I just used the extrude command in mattercontrol to easily show the problem.

 

The loop in the photo in itself is not a problem and is very typical. If you slowly pull it off while extruding does it keep curling back into the nozzle? If so the nozzle could be a bit too hot. What are the problems you are seeing with the prints?

 

If I pull it off slowly it won't stick again no. The main problems that I am having is that my first layer doesn't stick properly. Sometimes it leaves too much material (this will be at the start of a section) which later gets stuck to the printhead which then again pull everything with it. Or sometimes the filament stucks to the printhead, as shown in the picture, which pulls the first layer with it. Usually when the first layers are succesfull my print will come out fine. I just keep having troublem with the print coming loose. I use kafton tape on my bed, no glue or hairgel or whatever.

 

Sorry I can't help you much here. I never used Kapton tape. Aquanet hairspray sprayed on room temp glass and printed at 50C or 110C works fine for most situations with PLA or ABS. I won't tell you to remove it but that is what I would do.

 

Thanks for the advise. I read some articles about the right ingredients for hairsprays. I will try some of those, I dont think they sell Aquanet here in The Netherlands. I can always switch back to Kapton tape if hairspray doesn't work.

 

It's all here:
http://forums.robo3dprinter.com/index.php?threads/hairspray-survey.1532/

Aquanet 3 Extra Super Hold hairspray:
Water, dimethyl ether, SD alcohol, 40-B (alcohol denat.), VA/crotonates/vinly, neodecaoate copolymer, acrylates copolymer, aminomethyl propanol, sodium benzoate, cyclohexylamine, triethyl citrate, cyclopentasiloxane, fragrance.

Thor thinks that the key ingredient is Acrylates Copolymer.

Make sure you spray it on a room temp bed and then heat to about 60C for a moment to dry. Clean with water or alcohol. Reapply if it looks like the last print pulled a large area of it off. This will give the bottom surface of the print a nice glass like surface with many filaments if you have a good squished first layer.

 

Curling filament usually means either too hot or too cool. Looks like you are too cool. Try using 190 for PLA.

I also noticed that when you try to adjust the temp of the filament so that it streams perfect down without curling, it's too cool and won't adhere to the next layer properly. At 190, it seems to be the low end and I have tried using 212 for some filament. The higher temps are sometimes too sticky and it's harder to remove support. At 190 support and rafts come off nicely.




Sent from my iPhone using Tapatalk in Canada

 

I doubt it's too cool seeing that I print on 210. But I will test some other temps.

 

I have that problem on the first print of the day. First it bunches up all over the nozzle. I clean it off and extrude 10mm at a time and keep scraping off until it comes out looping like yours. Then, a couple more extrudes and scraping the nozzle and then it comes out fine. I haven't had much time lately to play but I wonder if removing the filament after printing rather than leave it in would be wise.