I don’t know if proper procedures were followed when taking off the nozzle, since at my school I print more than anyone, but they still think taking it apart past the point of the heatshrink is a job for the adults… however when taking it apart and putting it back together I do not know of any specific method or way that the teacher was following. I get the feeling there is some kind of issue or loose bit in there… It seemed like a really rushed job to me, and I already had to tighten other screws.
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Hey Logan,
If you are in the LA area then go ahead and bring it on in our shop and we can see about fixing this issue you are having.
-Maya
The Build Shop
Hi,
If you have had the unit apart one thing worth double checking is that the fan on the front heat sink has not been installed back to front. When its the wrong way around the PLA will overheat above the heater block and become too soft for the feed roller. Eventually (10-15 Minutes into a print) it will stop extruding. There will be a mess around the feed roller that needs to be cleared. Sometimes the PLA can be seen feeding out of the side near the stepper/feed roller area above the heated block.
This. We’ve diagnosed a few “broken” Rep 2’s that just had the fan mounted in the wrong direction.
Yup somebody messed up the head most probably. Have you been running regular maintenance? Do you have the new spring loaded mechanism to push the Filament in the Extruder against the gear to push it out? What’s happening is there is now a gap between the heated Filament and the Nozzle so the Filament bends and extrudes out from another outlet created during the messing about with the head.
I use Goof Off heavy duty wipes and AR Kleen Lens cleaner to keep the extruder going once it clogs. Have not had to dissassemble as of yet - and have a standby extruder on hand just in case.
I am located in Chantilly, VA. If not too far from me, I could come by and take a look.
First, it looks like you are working on a 2x. I also dont see anything from the picture.
It does sound like your nozzle is loose. Someone might have stripped out the threads! In that case you might need a new nozzle and aluminum block.
Hello Logan,
here are the steps>
1) take out the fan, let it hanging, turn on machine, preheat at 245 and load filament without passing it from the motor that pulls it.
a) if you can extrude, then your nozzle is OK and
this means that you have to >
and align all things so that the holes in vertical axis are aligned
turn off machine and mount it back not too tight and trying not to have any cable of the fan pressed
do not use metallic tools because you wil make a short circuit
b)if you cannot extrude this means you have plastic in the nozzle.
try to clean it>
http://funbiestudios.com/2014/01/unofficial-guide-makerbot-replicator-2-extruder-nozzle-replacement/
Hope it helps!
Anastasia
Hi Logam,
Unfortunately the “falling apart” is a known issue with Makerbot Rep 2 (ALL Gens.)
This is due to the manufacturer specifically choosing to not use vibration dampening fasteners.
I’d recommend coating pretty much all of them with Loktite. You might also get some star washers or replace the nuts with Nyloks.
Try to tighten all the screws wile the hotend is hot. Dont burn your fingers wile doing it. Make shure the heatbreak is screwed into the heatsink tight and the nozzle into the heatblock. And then the connection beween the heatbock and the heatbreak. Do not use to much force in order not to damage the heatbreak. And, wile you have disassambled the printhead anyways clean the filamentpulley using a toothbrush or something simular.
Hope this helps…
florian
I’ve had some issues with my hot end in the past that are similar. Not oozing out the side, but I have had issues where there was an ever so slight gap between the top of the nozzle and the bottom of the feed tube that screws into the heater block. That tiny gap caused me more issues than anything that has ever been wrong with the printer otherwise. If you are able, I would recommend buying some ceramic and kapton tape, taking the whole block apart, melt the parts clean or get a new nozzle and rebuild it, making sure that there are no gaps anywhere. Be very careful of the wire on the thermocouple. It damages easily and they aren’t super easy to get a hold of. Also, if you are replacing the nozzle, be wary of the super cheap deals. the inner profile of the melting chamber makes a big performance difference.
I can appreciate all the troubleshooting you have put into this problem. We recently had a bunch of problems that were similar to this on both our gen 4’s, minus the leaking out the sides of the heater block. I tried all sorts of things from cleaning out the drive gear and using a blow torch to burn out the filament guide tube (the threaded part that feeds into the heater block) and the nozzle. I have reamed them with drills and wire brushes, and even added spacers on the spring to add tension to the filament on the drive gear. All of those things returned the same result as we were getting before; the filament getting jammed at some arbitrary point into a print, and the drive gear chewing a bite out of the filament.
The only way we have achieved lasting results, is to replace the nozzles. Seriously. Just find a new nozzle, order 3 or more, and install them using the best nozzle replacement practices (heating the printer up to remove the old one, letting it cool down, hand tighten the new one in then tighten with wrench or socket wrench, heat back up, and finish tightening it). When reassembling the extruder, just make sure all your parts are put together correctly and tightly. Look at your fan. Are there and missing blades? If so, this will cause vibration that loosens all your screws and components including those in the heater block. When purchasing your new nozzles, make sure to do a thorough background check by comparing reviews across the web. Hope this helps, these printers are tricky. Best of luck!
Shameless plug for our very well-reviewed replacement nozzles. 
I have a low friction nozzle from P3-D on mine right now and I love it. when i switch nozzles and fixed my gap problem, I’ve not had a single jam since! You can get these on ebay. the company is local to me but I am only familiar with them via their ebay store.
I doubt a coating makes the nozzle that much better that it should cost $13 when they only cost $7 a Fargo
Hey! Glad to hear it’s working well for you!
Time to redo your hotend. disassemble it and replace the inner PTFE tube (3mm outer, 2mm inner diameter).
How to: unscrew the 2 lower bolts that holds the fan, heatsink and extruder, on the long cooling aluminum block there is 2 locking bolts that holds the hotend barrels in position, loosen them up and pull down both barrels. Loose the lock bolts that secure the heater resistors and the thermocouples, separate the barrels from the heater blocks and also take out the nozzles. Replace the inner tube with new ones and cut to size, cut out the insulation tape from the heater blocks and clean and run the correct size drill on the nozzle. Put all together again and install in position (do not assemble the extruder yet), once in position cover the heater blocks with Silicone tape from Autozone or any hardware store that sells them (they are for hot water pipes), run a bed calibration command from the printer and it’s first point, set both nozzles at the correct distance from the bed and then tight the locking bolts, finish running the calibration and once done, you can finish assembly the extruders. (It is a good advice though to open the extruders and clean the gears).
You are done for the next 3 to 12 months depending on how much you print.
11 days later
Just an update folks…I believe the print head was simply not screwed together properly. The teacher who works on it soaked the nozzle in acetone for a long amount of time, ranging between a few days and over a week. There was a bit of PLA left, but that came out when it heated up so it looks good. He was finishing assembling the whole thing today when I left school, and I am scheduled a bunch of times in the next few weeks printing, so I’ll update with the results. I plan to bust out 3+ prints tomorrow alone, so I should see how it ends up relatively soon. Thanks again for all the tips!
PS: The job I left printing just for the heck of it (when there was a slow but steady leak) actually printed perfectly! As I had hoped, I had removed enough of the leak so that when the job finished the leaked amount did not fall off of the print head and mess up the print. I’d guess it leaked around 10 g over the duration of the 3hr print, with a m&m sized bit of pla hanging out every 30ish minutes. I think there was a minor clog, and that combined with too large of a gap between parts was leading to liquid material seeping out where it shouldn’t have. Hopefully will be good now.