I really like the greg/wade style extruders overall, and the lulzbot variant is the best one out there of that type. That being said, I hate, loath and otherwise utterly dispise the stupid idler arm itself for one reason. Every time I need to remove the damned thing, the stupid internal M3 nut spins inside and strips it out. Literally every time. I've killed more idler latches over my 3d printing time just by doing that simple operation. So, after i broke my 10 billionth idler latch today, I decided to fix it. All that stupid nut does is hold the M3 bolt in place. Why not replace it with a heat set insert? It will actually strengthen the part at that point, and it won't strip inside!
So here it is
This is based off the latest 1.4c lulzbot variant, licensing is Creative Commons Open Source Attribution as usual. Please feel free to use this part in any manner you see fit. If I can save one person from the agony of a stripped idler arm nut socket, then it will all be worth it.
Instructions: insert one M3 heat set insert (http://www.mcmaster.com/#94180a331/=13ettuz) into the hole in the side of the idler. Then install it using the stock mounting hardware and bearing insert thingy in the stock locations.
This will fit any of the Lulzbot extruders, for all the AO-10x variants, the Taz variants 1-6, and the Lulzbot Mini. it should also fit most other Greg/Wade style extruders
Edit: If your existing idler bolt does NOT have threads all the way up, you may need to replace it with a new 25mm long M3 Cap head bolt. You can find them here: https://www.amazon.com/M3x25mm-Screw-Socket-Screws-100Pcs/dp/B0143GZQNW/ref=sr_1_1?s=industrial&ie=UTF8&qid=1469314964&sr=1-1&keywords=m3+bolt+25mm
This is an extruder part, ABS or similar material is warranted due to heat exposure