So this fell out of my makerbot rep2x today 5hr into a 15 hr print which then failed horribly. Any idea what it goes to? There seems to be a high pitch squeek on the far right upper back home position and it then has trouble going in the x direction (as in it just sit there while squeaking. So frustrating! Can’t believe I paid almost 3 grand for this and prints are about 50/50 success rate, except this large build where its 0! Not to mention iffy use of PLA. 
what’s the return policy? Hmmm? @MakerBot1 @bre_pettis
ahh, the twitter era, when posting stuff like this to the internet is the FIRST course of action instead of the LAST as it should be. seriously, you couldn’t just email makerbot industries support or post on their forums about a repair/replacement?
Hey, he’s bashing them. Personally I’m not about to complain about negative PR for MBI.
Errmmmm… Large piece falls out and you keep using it… Burn down your house much? 
Seriously though, Step-0 should be turn the thing off, unplug it, box it up and contact support for an RMA of some sort. That’s what you paid the MBI premium for!
Aside: Wouldn’t surprise me if the 50/50 success rate was tied to this part being loose enough to fall out. Hopefully getting a new unit will automagically make everything better, but…
@Sparr_Risher I posted this in the questions help area, looking for help, yah i kind of went into a mini rant but that’s just because i have no idea what that piece is and the manual doesn’t include a exploded schematic identifying each part. If you don’t have anything really to contribute then i don’t know why you posted other than to troll.
Sorry but it cant be said enough times, don’t leave a printer - any printer running this long unattended.
I hope MBI are kind enough to replace the part for you. (They should from the sounds of things)
@Andrew_Plumb This part fell out AFTER I stopped the print (it was still going as can be attested to by the rats nest of filament.) and was leveling the bed. It wasn’t moving in the x axis so i gently pushed the extruders to one side and heard a clang, saw this took a pic and asked for help identifying it after not finding anything in the manual. I’d like to fix this myself, rather than send this machine back and have to wait a week. figured someone here might have run into this issue already, which is why i posted in the questions and help area. I did go into a mini rant but that’s just because i’ve gotten frustrated with just doing simple things. The print i was doing was testing out how large i could print (an ant farm) and even the bit that did get printed seems to be angling to the right. which i thought the makerbots were much more dialed into making larger quality prints and didn’t have much drift.
@Chris_Smith That’s silly. There’s a $30k U-Print in my local makerspace that runs unattended 23 hours a day, every day, and has done so with no failures for the better part of a year. I wouldn’t leave a $500 kit printer running unattended, but eventually you cross a threshold, and the price and non-openness of the Replicator 2 puts it somewhere very close to where that threshold should be.
Yeah, if you were expecting to be able to fix it yourself you should have gone with one of the myriad of proper open-source options out there.
Aside from the formal support channels, your next best place for help is the MakerBot Google Group. You’ll find there’s a much more concentrated source of (ab)users there to “go deep” with the help than here.
That looks like a roll pin, which is often used to secure a gear or pulley on a shaft. A drive pulley coming loose from its shaft would be consistent with the other symptoms you describe.
Thanks Jim! Now I have a reference to which to start looking and hopefully repairing!
Right, I was missing the scale — I had it pegged as a quarter inch/5mm or so shaft, but looking at the wood grain I guess not.
Yeah. Pulley loose on or off a shaft sounds right.
Look at this video at 00:45 to 1:00. Can it be that pin?
Sure looks like that pin, @Daniel_Tedenljung
At least you made a beautiful afro
the funny thing is that I kinda of thought the same thing, then I immediately thought of hey if I get this working I could print out a plastic hair piece like they used to wear on that old liquid television short on mtv called Dog Boy! hehe. http://cdn9.liquidtelevision.com/wp-content/uploads/2011/08/Dogboy1.jpg
I’d say ignore @Sparr_Risher and @Chris_Smith 's accusations that a “kit printer” cannot run for long periods of time without supervision. As long as you have a proper spooling mechanism, secure connections, and are within your printers parameters then you’re fine. My i3 has been left overnight, unattended many times, and a lot of other people not as savvy as myself have done the same without problem.
Although it’s probably a good idea to have smoke and CO alarms installed, especially for overnight runs. If the thermistor has an interesting failure, things can get way too hot to be safe.