I have been using my CreatorBot for awhile with hardly any issues but recently pretty much all of my prints have been failing, even ones that I have been able to print successfully in the past. What seems to be happening is that as the print is running a bubble of melted plastic forms on the side of the extruder nozzle. This bubble gets bigger and bigger as the print progresses until it is large enough to come in contact with the plastic that has already been laid down on the bed. When this happens the blob dislodges from the extruder, fuses with the part on the bed and creates a spot where the plastic is much higher than expected leading to eventual print failure. What I Have Tried: Based on a bit of research that I did it appears the most likely cause for this kind of issue is that the extruder tip is too close to the bed and the plastic is being forced out any other space it can find in the hot end to relieve the pressure. To remedy that I tried moving the tip as far away from the print bed as I could get it before I started to experience issues with consistent adhesion between layers. The problem still occurs even when there is plenty of space between the bed and the nozzle.
The amount of plastic making it onto the bed seems to be the same as it was before I started having this issue as well so I don't think it's a nozzle-clogging issue.
Any ideas what may be causing this issue or things I should try for troubleshooting? If it would be helpful I can attach some images as well, thanks!
you might try cleaning the nozzle. If there's any plastic built up around the tip the new plastic may want to stick to it as it would your print causing buildup. Lower the print bed, heat up the extruder and wipe the tip clean. you may also want to run a small drill bit up the nozzle to clean out the inside. You don't want anything on or in the nozzle as or more attractive to your new plastic that the printed layer below.
I experienced this problem early on too. There was some plastic making its way out from in between the nozzle and the aluminum heat block. The way i fixed this was to make sure the ends of the nozzle and the threaded insert were square and had enough contact area. Then, the nozzle was threaded into the aluminum leaving about .020" between the nozzle and block. After that, i thread the insert with the PTFE tube into the back of the block and tighten with pliers. Doing this seems to provide a positive seal between the nozzle and the threaded insert.
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