MakerBot Replicator 2 home axis not homing

My MakerBot Replicator 2 is not working. There are two problems (perhaps unrelated). The main one is that the axis will not home, and the second (perhaps not even a problem) is that I found a stray plastic part on the base of my MakerBot and I'm not sure where it came from or even if it is part of the MakerBot!

I've posted pictures and video: https://www.flickr.com/photos/dumble...7647483786299/

https://vimeo.com/106815539

You can see that the print head block moves towards the end but fails to touch the switch that turns off the drive; the switch itself is working (I can trigger it by touching it with a screwdriver) but there doesn't seem to be any part of the head that could ever reach it.

How should I fix the mechanism that stops the head drive when it homes?

It's worse than I thought. The last users mentioned that an overnight print had failed. I It's not looking good :-(

https://farm4.staticflickr.com/3861/...565e6029_n.jpg

You have got a lot going on there.

I immediately noticed a few things.

1. Your X axis belt appears to be kinked somehow. The belt should not turn on itself, it should wrap around your motor on the right, attach to your carriage then wrap around the X-axis idler pulley. Somewhere along your belt, it appears to at least have a twist in it. This very well could be causing the carriage to not home properly, due to that kink getting tighter and tighter the closer it gets to its “home” position..

2. That plastic piece you said you found, that is the bottom half of your active cooling duct. That bit is attached to the fan duct on the left side of your extruder. When printing PLA active cooling is pretty much required for quality prints, and I would bet it contributed at least somewhat to what caused that print failure. Hopefully you can attach it back to the rest of your duct, if not then you can either purchase a new one or some replacement, or even print out a replacement .

Attachment 2881

There could be other things at play but those two stood out immediately to me.