filament adhesion issue

Hey guys, I've always found really helpful solutions to most of my printer problems on these forums in the past, but I can't seem to find a single result on my issue in particular; it has to do with the fusion of the filament. See, whereas many people have challenges getting the first layer to stick to the bed, I have a problem with every following layer... The first layer sticks just fine, but somehow the hotend just ends up pushing off the rest of the filament it tries to deposit, causing the final print result to be a single sheet of well-adhering plastic stuck to the bed, and a glob of plastic that should be the rest of the print. To give you guys an idea of my printer setup, I'm using a Rostock-type delta printer that I built, running Marlin, and I've been using cura and the pronterface printrun gui to slice files and send them to the printer. I think I've gotten it pretty well calibrated, and am printing 1.75mm ABS filament (measured at 1.71mm) with a 0.3mm nozzle (extruded filament measured at 0.34mm). I'm running the hotend at 240 deg C, the heatbed at 110 deg C, and am using a glass plate elevated a few mm above the heatbed PCB with hairspray for adhesion. I've tested the z-axis motion of the hotend to see if it wasn't moving high enough for some reason, which shouldn't really be a problem for delta printers anyway (right?) as the rest of the axes are moving correctly, and though I didn't test toooo carefully, I took my digital calipers and measured the accuracy of a 100mm jog in the z direction, and as far as I could see, it was spot on; if you guys think that may be the issue, that it isn't rising enough when it attempts to change layers, I can check that out in more detail, but right now my 'workshop'/bedroom floor is littered with little single layer sheets of a simple box I am attempting to print as a test object, and I thought I'd turn to a group of more experienced users, since I'm new to additive manufacturing, and even to the intricacies of CNC type machines, and I've been wracking my brain for over a week and have gotten basically nowhere.

Thanks in advance guys!

Edited 1 time(s). Last edit at 09/03/2014 12:16AM by vvarma.

How fast are you printing and what is your layer height?

Definitely look at layer height. Running at a height equal to the diameter of the nozzle will cause problems. Also, ambient temperature. Is your room too cold?

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0.1mm layer height (but I've tried 0.075 to 0.2 with similar results), and I've kept the printing very slow to rule out errors associated with that, so I've tried speeds between 15 and 30 mm/s. My room is set to 69 deg. F, but ends up at least 5 degrees higher due to all the devices I have running in there.

Hmm, 69 degrees seems kind of cold. Maybe try pointing some incandescent light bulbs, 60 to 100W towards the build plate during printing just to see if that helps. Or try covering the printer with a box if you have one big enough.

70f is kinda cold. Its almost 10f hotter in my computer room where my printer is.
ABS doesnt like to be cold or drafty. PLA is a little nicer when it comes to enviroment changes from what ive seen.

I had to actually run out and buy some incandescent bulbs, but now they're all hooked up, and I'm also going to put a bit of a delay between the bed heating up and the actual start of print, so the air in and around the printer is nice and warm. I'll let you guys know as soon as I finish a test print and what the results are. Thanks for the prompt responses, everyone!

AAAANNDD I walked in on a shattered glass plate (somehow, I don't believe there was ever a print head crash). In any case, I'm ordering a borosilicate sheet that won't break so easy, and I'll let you know how it works in a few days when it gets here

Wow thats nuts!
Ive been using normal plate glass for months without issues at 110c

it honestly could have been the fact that the room was a little cold, even with the incandescent bulb, and when the hotend started to print the heat from that made a gradient down the length of the plate (the print began at the edge); the other possibility is that the print head was pushing down on the edge of the platform, even though I printed something there before, and I didn't notice a print head crash. in any case, I hope I don't have those problems with borosilicate glass, but I'll see. let you guys know in 3-5 business days when the plate gets here
OH I almost forgot, when I came in and saw the build plate all messed up, the hotend was also offset from where it should have been; though I haven't had skipping issues before, the print head could have gotten caught on the glass somehow (??) causing the motor to skip steps; the other possibility with regards to that is that the already cracked glass, making an uneven print surface, caused the hotend to catch and the motors to skip. In any case, nothing to be done now.

Hey guys, so I've just got everything set back up the way it should be, recalibrated the printer, and tried test printing a little cube; The issue this time is a little different; instead of all the layers but the first getting pushed around, leaving only the first layer, they appear to be getting deposited, however they're being set down in a way that only a picture can describe, so an image of the object, still on the heat bed, has been attached. I haven't tried it with the incandescent bulb since setting it back up, so I'll retry it with that when I get the chance (things are quite busy over here).

Looks like your first layer is too low looking at that picture for one.

but would that really mess up the rest of my print? I'll try adjusting the first layer height to see if that does anything, but what I'm most concerned with now is the fact that my prints don't resemble much of anything at the moment. That print was just supposed to be a simple little box.

Damn it all. Have any of you ever had experience with a J-Head style hotend just breaking? I noticed that my printer wasn't extruding nearly as much as it should have been, so I tried to unscrew the two halves of it apart to clean it, which I have done before. Upon doing so, the threads on the aluminum block just sheared straight off the dang block. I don't quite understand how that even happened, as I had taken it apart before the same way, but this time it took so much force it literally ripped the aluminum apart.

In other news, I believe the problem mayyyy have been the fact that the hotend got clogged quickly, which caused massive underextrusion. After I get and install the new one, I'll let you all know if my theory is correct, and if it prints correctly from there on out.

In other other news, these parts to replace ones that have gone bad will, at this rate, match half of the cost of the printer itself in a matter of a few more months x.x