Any tips to prevent these ghost layers? Hob bolt is tight, cleaned the extruder nozzle, correct filament diameter inputted. Despite all this, on almost every print ghost layers occur and kinda ruin the object.
Try a different program for you gcode
maybe too much tension and your hobbed bolt is getting clogged?
Donkow
Run it real slow and see if that makes them go away. It could be that pressure is getting too high in your barrel, stripping filament, then after it gets back down it restarts. Also watch and see if you get poor infill sometimes. If you’re just getting missing perimeters and you never get “ghost infill” then start playing with your slicer.
I had the same problem what @Nick_Parker describes. It happened when temperature was too low and pressure inside the barrel got too high that it skipped some filament. At what temperature are you printing and which material ?
It’s PLA, hot end set to 185C. Thanks for your suggestions! Slowing down the print seems to get it back on track, but it’s strange because it will start of perfect and at some point just misses about 3 layers, perimeter as well as the infill.
Try a higher temperature. I print my PLA at 208. When i print at 185 i get the same problems as you but mostly it even stops printing and makes airlayers because my hotend completely jams.
I’ll have to try that out, the base layer always lays at 215C for adhesion, I’ll incrementally increase the temp of the following layers and see what works best. Thanks!
Maybe your extruder motor(driver) is getting too hot and skip steps.
Mine does that when the a axis binds. It will be binding up which makes all the previous layers thinner, then the tension will loosen off and cause a sort of jump in the next layer.
This all VERY helpful info. I, too, have similar flow issues.
Tnx @Spenser_Lee for asking this Q. @Aaron_Leclair , that
situation sounds familiar. I might have had that in the past.
But sometimes it may just be you want your hotend to work faster than it can. If slowing things down with no further changes helped maybe this is the case. There is a “speed limit” for a given configuration (hotend, extruder, spring tension, temperature, current, etc).
Also, are you using layer heights that are full steps on your Z? You want to be. One possible reason for the increase in pressure that causes these lost layers is unusually thin layers. If your z layer thickness isn’t steady, sometimes you’ll be extruding into a much tighter space between nozzle and previous layer, which will increase pressure and might cause something like this.
I have the same issues but i’m very impatient so I just let it be and then brush over them with a wood burning iron to clean them up.
I would feel your extruder stepper motor every once in a while. If it’s too hot to touch, you may be driving too much current and it might give up for a little while while it cools.
Make sure you have a heat sink on the motor driver for your extruder motor, and a fan blowing on the heatsink. In my experience the motor doesn’t skip steps as a result of getting too hot, but the stepper motor driver chip does. If run too much current through the driver ship it will go into thermal shutdown and cause intermittent filament starvation. Proper cooling of the stepper driver ship helps. You may also want to increase your hotend temperature, make sure there’s nothing binding in the filament path, or even go to a geared stepper motor for the filament drive.
Thanks for all the responses, it’s definitely not anything with the motor, I ensured it was correctly receiving power and runs only just warm when printing. It has a heat sink and fan as well. I’m going to try running at a hotter temperature, but also try a new slicing program. Right now I’m using a client optimized (kind of) by the manufacturers for my printer that runs over skeinforge, but I’d like to try Cura. It seems to slice instantaneously, and has a nice interface, but for some reason I can never get the base layer to stick with the Cura G.Code. Then it all gets clumped up on the hot end and can’t print. Do any of you guys have experience running Cura on non Ultimaker machines? Thanks again for all the feedback!
I’ve recently seen this problem with a spool of filament that has been sticking on a hacked together filament holder. The spool didn’t fit my normal spool holder, so I just threaded a dowel through the hole.
In any case, the filament runs inside the spool center hole. When the spool turns to the point where that filament hits the dowel, it requires more force to get over the “hump”. This causes the filament to pull back on the extruder a bit.
Mine is a temporary problem, but could something be pulling back on your filament?
I think he was saying not that the bolt slips, but since it doesn’t slip, the whole X axis moves UP in the Z direction a little bit before the reel pulls free.