sybaritestudio - PLA

sybaritestudio - Replicator 2, temp was 230, 240 back to 240. I've followed all the support videos on Makerbot and still such things are happening

3dcgmodeler - Check the extruder motor gear tension, if its to tight it will cause the filament to break.
also check the filament diameter occasionally for correct diameter, I have had issues with air prints, also and usually its the filament causing the problems.

bioluminescence - I used to get this quite a bit. Sometimes it was due to bad filament - when I extracted the filament end there would be long fiberous ribbons coming out of the end. This usually happened more often with a very dark filament (black, red, etc) than with pale filaments (white, natural, yellow). These fibers would seem to get jammed in the inner gearing and removing the filament took a fair bit of effort and a pair of pliers.
Alternatively, sometimes it would be because the model was curling up at the edges . If I was printing something with multiple parts or multiple islands, and the print curved up on the edges, then the print head would scrape against the raised edge of the print every time it did a layer and wouldn't let the plastic out. This seemed to jam the plastic in the printhead reservoir and it would, as you say, air print.

If printing the same model always fails in almost exactly the same place, then it's more likely the latter. If it can fail just about anywhere, then check your filament and see if it's the former.

If it's the filament problem, then if you're QUICK you can pause the print as soon as it starts to fail and (on a Replicator 2 at least) unload and reload the filament again, after clipping off the fiberous end. Pain in the backside, but if it's the only filament you have, then it's a workaround.

If it's the shrinking/edge issue, then I can only recommend printing objects 1 at a time (if you're printing multiples) and/or putting a large cardboard box over the top of your printer to act as a heat-container to slow down shrinking and/or printing at a different orientation to see if the angle you're printing is making it worse. (Printing a 45 degree overhang is more dangerous as the edge is thinner and thus curls easier).

sybaritestudio - Thanks,

My prints are definitely not doing the curling side of things since the "air printing" occurs randomly.

I already do this...
"If it's the filament problem, then if you're QUICK you can pause the print as soon as it starts to fail and (on a Replicator 2 at least) unload and reload the filament again, after clipping off the fiberous end."

I already have a specially made enclosure for the top, sides and front of the Replicator 2 to minimize ambient temperature fluctuation from within it.

I'll double check the diameter and adjust the extruder motor gear tension..
Hopefully that will take care of it.

printedsolid - I installed a filament cleaner, a little piece of wrapped up microfiber cloth, that all filament feeds through before going into the extruder.
I've also stopped buying 'bargain' filament and stick with reputable quality suppliers.
Between the two, air prints are now few and far between.

nyl0cke - 24 is really high for PLA, it's probably jamming, try 200 or 190

nyl0cke - I meant to type 240 of course

tjones - interesting because makerware's default settings are set to printing at 230c... why do you think that is? - i'll try printing at lower temperatures next time I run into this.

nyl0cke - That should be an ABS setting, that's stupid high for PLA, just asking for a jam

linuxpredator - Using the stock allen key, just tighten the filament on the stepper. It's behind the fan on the replicator 2 extruder.

jezzmund - Every 'air print' I've had ( over hundreds of hours of printing on several different machine types) has usually been down to an inconsistent filament diameter.
Always use the best quality feedstock that you can, and a small dust remover of some sort certainly helps too...
230 degrees is far too hot for PLA, even when using a bowden type extruder, you may be experiencing some polymer crystallisation in your hot end as a result. I'd advise dropping the temperature and seeing if that makes a difference...

sybaritestudio - Thanks all... good point on the crystallization. Will try it.

makerbeck - When I have run into air prints after a print starts out it has often resulted from the filament inexplicably breaking on what looks like a perfectly spooled roll. I had a roll recently that printed great most of the way. I was getting ready to do a very long job and took a look at the spool and the inner layers were really messed up. I switched out the spool to be safe and set that one aside for shorter jobs or respooling. I did not want to take the chance of the filament getting caught and not feeding properly.

tomek - I recommend the E3D extruder. It has been the perfect solution to my clogging issues. Furthermore, a 0.5mm nozzle will help (I use 0.4mm though for finer detail.)

tomek - Sometimes you need to toss filament though. I've had completely unsuitable filament that would clog on an otherwise flawless system. Especially this is a problem with black filaments, because shady manufacturers can hide low-quality plastic/impurities in the dark color

fabhappy - What sort of detail does your part have? What Z resolution? No one has mentioned how printers can start air printing when you're doing fine features and the retract moves end up retracting too much. I've had that happen on my Replicator 2 at 0.1mm on small features, as well as on my UP! when doing lots of smallish circles. Try printing something tall and simple like the single-walled test pieces on Thingiverse, and maybe you'll see that those print correctly?

jms3dprinting - I have had problems when the stl model is not correct and the printer doesn't recognize it as solid. If the filament jams and there is nothing to extrude or the model warps and you get a gap started the pile of filament will lead to a "transporter accident"

jefflaird - Not sure if you are still having issues.

After having a filament jam, pulling the drive block out according to video from Makerbot support, then reassembling - we were getting a similar problem. Max 15 minutes of printing before jamming, then "air printing". After back and forths with tech support I was looking at the printer when it dawned on me that I had stupidly reassembled the drive block with the heat sink facing the wrong way.

Flipped it so that fan was blowing toward the drive block and the fins of the heat sink pointed toward the fan....

sigh.... 2 weeks of beating my head against a wall....

J

vinnie90 - Makerbot run colder than what the setting you put on it. I have 3 and all run colder and everyone tells me the same.

reetu0 - very good post
https://worldforpcapp.com/whatsapp-for-pc-download-windows-7-8-10-free/