General 3D Printing Thread


 
So I feel like an idiot...the stepper wasn't moving because of the min temp setting for extrusion (face slap). After switching out the pins in firmware and plugging into e1 I tried to move the stepper in pronterface since I was already connected to my laptop and it wouldn't, but it tells you why. Before I was doing it from the LCD panel and it doesn't tell you that, just doesn't move. Now looks like I might be disassembling my E3D to look for other jam issues. It will work if I push the filament with my hand, so not completely jammed, maybe it's just burned out some? Any suggestions on cleaning these all metal ends? Before with the J-Head I would end up replacing the PTFE liner when this happened, and which ultimately got me to buy the E3D... :(
 
I don't get it, if you can push the filament through the hotend by hand then it's not jammed, and it's hot enough to melt the filament. I would think the stepper would be able to do at least as good as it does by hand. And if the stepper was unable to push the filament it would just start to grind into the filament and slip, the motor would still be moving. So I wouldn't bet on a clogged hotend being the issue.

What does the LCD or pronterface report as the hotend temp? If the electronics is told the temp is too low it will prevent the motor from moving to prevent "cold extrusion". If you can extrude filament when pushing by hand the hotend is hot, apparently.... The LCD or pronterface will tell you the story there, if it reports hotend temp below the extrusion range (even though you can extrude by hand) then there is an issue with your temperature sensing circuit or an error in the config. In the config you could have the min/max temps for extrusion screwed up, or you could have the wrong thermistor model selected somehow, or there could be a wiring issue or solder issue with the hotend thermistor on the RAMPS board like I had (or a bad thermistor), or something else wrong with the RAMPS board.

As for cleaning, I always cleaned my J-head heater block/nozzle by heating it with a blow torch and melting/burning out any filament that is stuck in there (with the block removed from the plastic body of coarse). Then I would soak a q-tip in acetone and wash it out on the inside (after it was cooled of coarse), the nozzle always came perfectly clean after that. BUT I have never done this with my E3D head yet, I assume the same method would work...
 
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I really have to put a lot of force into it when passing the filament through by hand. Putting way more pressure on the extruder than was ever done before by the motor.
 
You may have some junk in the filament path. Here's what I do:

1. Insert fresh filament by hand at 250C until you see extrusion and then immediately yank out the filament completely.
2. Cut off end of filament and repeat step 1 three more times
3. Crank up hotend to 300C (make sure your max temp in firmware is at least 350) and push through about 10 cm of filament by hand. Yank filament out and cut off melted bit.
4. Drop temp back to normal extrusion temp and you should be good
 
Yah, one benefit of an all metal hotend is you can heat it up a lot hotter than a hotend with PTFE... So Tom is giving good advice and speaks from experience.

That said, the extruder stepper should still be turning even if you have a completely clogged hotend. The grooves in the hobbed bolt will grind into the filament and slip, so the filament wont be moving but the motor will still be turning. Is this the case? If the motor is not turning then you have a different problem, not just a jam, IMHO....
 
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In any case, it will be apparent that the motor is still turning or trying to turn when you try to extrude, even if there is a clog. I have had the hobbed bolt eat into the filament and slip on multiple occasions but never seen the motor fail to spin. I guess if the pressure is really high on the filament maybe the motor will stall, but on my spring loaded Wade's extruder I don't see that happening unless you crank it down REALLY tight.... Not sure how other extruders are built so I cant say for sure about them, but the filament isn't really that solid and a stepper motor should be able to grind away at it pretty easily when jammed in any extruder I would guess.

At any rate, if the motor is trying to turn and the hotend is not extruding a clog likely your problem, if the motor is not trying to turn I would say you have other problems...


EDIT: What kind of printer are you working with?
 
Yeah, it's eating away at the filament. The reason the motor wasn't moving was because I didn't have the hot end heated up, so marlin was preventing motion. I'm using the makerfarm i3 8". I'll give Tom's clean out technique a try this weekend.
 
Ok, I have the same printer and now have the same E3D hotend as well...
I've had the filament jam on me twice, but both times while trying to retract the filament to change color. Before I pulled it apart I decided since I have this fancy all metal hotend that can go hotter than hell I might as well crank it up and see if I can push things through. I cant recall the exact temp I used, somewhere around 250-260, then I set the machine to extrude a bit a filament, meanwhile I used my hand to squeeze tight the spring loaded part down on the filament. Both times this pushed the jam through and filament started extruding, when I went back to normal temps everything worked fine.
 
I bought a piece of 1/32" Ultem (0.03") from Amazon for $18 because I needed a "filler item" to get prime shipping on something else. I cut it down from 12x12 to 8x8 with a pair of scissors easily as it is pretty thin. You guys weren't kidding, ABS sticks to this stuff like crazy. The only issue with it is that as mentioned it does like to curl up / bow. I was thinking about using a light spritz of 3M spray adhesive and clamping it down to my aluminum heated bed would work, but I'm not sure how the glue would interact with the PEI at 100C (adhesive is rated to 150F). Any better ideas?
 
I tried 3m with a thin sheet and it turned out miserably. I think a strong epoxy with a flat board and 45 lb or so weight on top while it cures would probably be best.
 
Confirmed! I had a wonky aluminum plate and took a bit of scrap Ultem and hit it with the spray adhesive. At room temperature it was like a dream, perfect adhesion all across the material. When I heated it up to 100C along the way the adhesive just turned back to liquid and it curled up like an orange peel. I'm hesitant to use epoxy, because I'm certain I'll bond the wood and weight to my heatbed so I'm giving it a go with silicone right now. Squeegeed a thin layer of that across the Ultem and stacked a piece of glass, a cast iron pan, and about 30lbs of weight on top of it. We'll see how this looks in about 12 hours.
 
I've bought two peices of ULTEM, the first was 12X12 at 1/16" (.0625") thick. I cut this one down with a plexiglass knife cause it was thicker. I really don't recall any problem with this sheet flexing. The next sheet I bought was 24X24 at .o4" thick, I cut this one into 9 sheets with a plexiglass knife as well. These pieces are thinner and much more flexible and didn't want to lay flat. At first I used them with the bow side down in the middle and used the clips to pull it flat, but the curl from ABS on larger prints would pull it up and cause problems between layers. What I do is spray a glass sheet with hairspray, then put down the ULTEM, then put another glass sheet on top of it and clip it to the heated bed and bake it until the hairspray dries. This holds pretty good, but will come loose after a number of prints or after you have one print stick down really solid. The good thing about that is when starts to come loose you can just pull it off and wash everything with Windex (seems to dissolve hairspray best) and start over.
The reason I didn't use glue is because I want to use both sides of the sheet eventually, cause they do seem to kinda wear out, or at least my first one did.

EDIT: Don't pour Acetone directly onto hot (ABS TEMP) ULTEM or it may shatter a bit. If you do, pour it on the rag and wipe, don't dribble it on the ULTEM and then wipe... 'cause the ULTEM will kinda shatter if you put liquid Acetone on a hot sheet...
 
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That's interesting that the acetone shattered your Ultem. I wipe mine every couple if prints or so at 95C with no issue.
 
It's happened twice on my thin sheet(s) after dribbling acetone on ultem at ABS temp of 110C while trying to remove a stubborn section of the skirt from a previous print. I've never had it happen when the acetone is on the rag, but dribbled liquid on hot surface = rapid evaporation and the ULTEM can shatter. While shopping ULTEM I noticed mentioned glass being embedded into it at various ratios, so not sure if this factor has anything to do with shattering and I don't really know exactly what I got here in that regard.

It always seems to be the skirt that doesn't like to come up clean that makes me resort to solvent to get the print surface clean.... Come to think of it, perhaps I should increase the number and/or layers on the skirts I print so they are more solid and might come up in one piece... I've just been printing them enough to purge the hotend lately, never really thought about printing them thicker for easier removal until now.
 
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I have alot of issues with just putting kapton tape on my build surface. It always wrinkles, I can't get it on smooth.
 
Lesley M said:
I have alot of issues with just putting kapton tape on my build surface. It always wrinkles, I can't get it on smooth.
Click to expand...

Soapy water with a squeegee will help you. But I would ditch it altogether for an Ultem Sheet. You can get them on amazon or mcmaster.
 
Lesley M said:
I have alot of issues with just putting kapton tape on my build surface. It always wrinkles, I can't get it on smooth.
Click to expand...

I have become an expert at this, here is what I do....
First of all, I have a long 7" roll of kapton so it covers the glass in one pass... I start out with a large bowl full of water, then roll out about a half inch of kapton tape and stick one of those wooden shishkabob skewers to it and wrap the tape around it. Now I roll out the kapton long enough to cover the glass plus about an inch or so extra and cut it from the roll. Now you have what kinda looks like a kapton flag... don't let the sticky side fold back on itself! Now dip the kapton in the water, sticky side down, I also put a few drops of water on the glass. Now move the kapton over the glass, let it lay down on the glass naturally from the far end of the stick, you can take a couple shots at it to get it centered if need be, when wet it should pull up pretty easily. Once it's positioned well take something like an ID (DL or whatever, something with a smooth edge) and start to squeegee the water out from under the tape. I run the ID out from the center to the edges and go in a circular pattern around and around, the wrinkle and water will work out. When you have most of the water and bubbles gone cut the tape off at the edge of the glass and bake it on your heated bed for a while to cook the rest of the water out, occasionally smoothing again with the ID until it is perfectly flat. I've been able to get perfectly flat bubble and wrinkle free kapton coated glass surfaces using this technique... And speaking of glass. I've got a borosilicate glass sheet, it's much flatter than window glass, which is important to get good first layer adhesion...

edit: I've used dish soap in the water but have better results without it. I've also used a squeegee but for some reason I don't get good adhesion to the kapton afterward, I think maybe the rubber rubs off on the kapton or something, a plastic ID works better for me.
 
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