Help needed with extrusion problem.
After months of successful printing I’m now running into various extruder related issues. It seems that I’m having a couple of problems. For PLA, it all seems to extrude OK but the PLA just falls off the bed (see the circle in the photo). The photo is pretty good, normally it all comes off and ends up a great mess.
For ABS I get the extruder gear stripping the filament and the ABS stops going out of the nozzle. It’s like the extruder motor is unable to force the ABS through the nozzle. If I push it down a little more I can get it to re-flow and it continues on.
Both problems are mostly prevalent on the first layer. I have replaced a thermistor and also replaced the whole hot end with no improvement. I have tried upping the temperature an extra 20 degrees. That does not seem to help either.
Any ideas? Thanks.
Is the stepper skipping or is the drive gear slipping on the filament?
I had the same problems… Printing on kapton tape is for some the best thing and for other a pain in the *. I bought a printing plate from http://mtplus.de in Germany. Costs about 55€ plus shipping but does the job. No loose prints, no kapton tape, no priming with hairspray or abs juice. Just printing. Worth its money 
@Wayne_Friedt The drive gear is slipping on the filament. I’ll try to upload a video of it.
@Tim_Hale_Freever I’ll check it out. Thanks. I have not had problems in the past. However for this plate I used the windex trick to get it on smooth. I wonder if that is causing issues.
There can be a fine line between to much tension on the filament bearing and not enough. If there is a partial plug then it can have the effect you are describing. If the hotend has shifted so the filament inlet hole is no longer centered with the hole above it can cause this. Then over tightening the bearing distorting the filament will compound this problem. When you extrude into air how does the filament come out, straight or curling?
@Wayne_Friedt The ABS does come out curly.
Does the photo above look like it is too hot or too cool?
If it comes out curly then that is typically a sign of a partial plug. maybe there was some debris in the filament that wasn’t visible causing this.
The extruder gear is plugged up which compounds the problem.
If I remove the hot end from its mount I can manually push some PLA @ 195 degrees through. It take a little pressure, but it’s what you would expect. I can do the same for ABS at 245 degrees.
While the hot end was out, I tested the extruder’s grip on the filament. If I run it through at 100 mm/min and try to stop it by holding it, it is pretty hard to stop. I adjusted the tension and it was pretty strong.
So if the hot end is OK and the extruder is OK, maybe it’s the alignment of the two?
@Wayne_Friedt I have also cleaned it off and it looks OK. There doesn’t seem to be any wear on the gear.
When I pushed the ABS through this time, it came out pretty straight.
Thanks for your ideas
I would say that if the problem presents itself only in first layers it’s not the extruder’s fault (plus the hotend was replaced and the problem persisted, as I understand).
Could be bed temperature or just surrounding temperature - has anything changed in the environment around your printer since that problem started? Like, you know, winter came. In my case the temp in my room dropped by 4 degrees.
@Igor_Larine Well it seems you may be right about it being an environmental problem. I just opened a new, sealed packet of ABS and it printed the first time, perfectly.
It is Summer here and it is quite humid. I think that all my old filament has absorbed too much water.
Tomorrow I’ll try to dry out some ABS in the oven and see if it prints better.
Yep, most of my filament is too moist. I have a 1KG bag of desiccant on order, hopefully after baking that I can get the moisture down.
It’s interesting, though, how some filament absorbs more moisture than others. In my case it seems the clearer colours seem to absorb more.
Thanks everyone for your help.
