I’ve been keeping an eye on it today and it looks like there’s a bit of backlash in the extruder gears. The click occurs when the filament feed changes direction. I’ll re-adjust them after my current 9hr print.
Scott
I had clicking and got rid of it by disassembling the extruder, removing the bearings and putting a thin film of goop around their outer race where they meet inside their housing bore in the plastic. Use a small amount so it doesn’t get inside the bearing. (Do not do this to the idler bearing that presses against the filament obviously, lol).
This will help to prevent the bearings from slipping or shifting in place, which was the cause of my clicking.
I took the head apart and found that the large herringbone gear is the problem. One side of the gear runs loose. It’s either out of round, or the center is off. I took the herringbone gear from my Buda extruder, and now it runs smooth.
Scott
After two months of printing the PEI tape is starting to bubble everywhere. I’ve tried to cut them with no luck. 
This is on a Taz 5. Do I just cut it off and buy new or do you think Lulzbot or Matterhackers will replace it?
theBlock, why don’t you contact Lulzbot support.
I read one posters comment about hitting the PEI with 2000 grit sandpaper so I used the 1500 grit paper I had on hand and now everything is sticking like magic.
As for the air bubbles there are less of them they are still existent.
I have seen several people now post about air pockets under their PEI on the TAZ 5, I wonder if Lulzbot used the wrong adhesive?
I did mine months before the 5 was out based on reviews here and I used the 3M tape (12x12) that was suggested and I don’t have 1 single bubble in all that time.
What thickness PEI sheet did you use? I did my Kittaz using the 3M adhesive and .01 PEI sheet. I have a few bubbles, but that was due to my application of the film and sheet, and not something that developed later. They have not caused me any significant issues (yet), but if I do, I have spare adhesive and PEI.
Scott
Mine was 1/16" or 1.59mm. At the time I had no idea what thickness to buy so I just took a guess but I would say it was a good guess as it’s been working perfectly for me.
Just to save everyone alot of time and trouble. About 6 months ago I was trying every print surface/solution known to the print community, when I came across the idea of PEI, after wasting $100’s, (printnz is a waste of money). I went to amazon to purchase a sheet of PEI and they were sold out of the thinnest sheets! So I purchased a 1/8" thick 12"x24" peice. I cut it into 2 12x12 peices and applied 3m 4" doubleside tape to the glass bed and stuck the 1/8" thick sheet of PEI to it. I have never looked back!!! End all solition here. Im very pleased I got the thick stuff because no bubbles or tips and it stays perfectly flat, and indestructable!!! 
just use a glue stick (2-3 layers) when re-apllying glue spray water on surface and whipe off glue, then use some alcohol, then re-aply glue. I print with all materials, nylons and tritan etc. No failed prints!! If you dont use PEI you are thick headed and waisting money and time. Imagion 100% success rate. Hope this helps, any questions email me suntornpogasic@gmail.com
Oh and just to answer a few of those questions about nylon on PEI, yes, yes and yes it works great! Just apply pva glue stick. Here are herring bone gears I printed with taulman bridge.
Those turned out great! Send me a set haha 
Nice! I have an unopened spool of Bridge sitting on my desk. What size nozzle and what slicer and settings did you use?
Scott
Hi guys
Quick question I have the taz 5 and have probably printed 80 hours worth of prints,every print stuck like s**t to a blanket ,abs and pla ,I’m now struggling to get anything to stick, is this normal
Cheers
Nope, not normal. You are either too high, too close, or not a thick enough starting layer, underextruding or have some oil residue on the bed.
To check, clean the bed with isopropyl rubbing alchohol, set the starting layer height to at least 0.4mm for a 0.5mm nozzle, set the nozzle so you are getting good contact but not paper thin beads, etc.
piercet’s advice is good. Read the post in my signature for more information and examples of a simple 1 layer model you can use to test. If I had a dollar for every PM and email I’ve received from folks here and the other forums where I’ve posted this saying that they wish they read this sooner, I’d have enough to buy another printer!
Cheers I’ll check the first layer height later
Thanks for the link I’ll have a read through and see if I can resolve the issue
I have to disagree. I attempted to use PEI last December (BuildTak). Bubbles and inability to consistently tune that elusive first layer height causing either objects to stick or come off. It took all the fun out of using my printer. One print would come off great, the next would stick too hard or come loose before the print was finished, nothing changed between the prints. I gave up after two sheets ruined and only about 15 prints. Yes, I had ABS prints stuck so hard on the last print, I had to remove the PEI sheet to get it off (almost broke the glass).
And don’t even attempt to print any flexible material on it.
I tried the PrintNZ sheet about three months back, FAR EASIER to get successful prints. It still requires attention to first layer height like PEI, but no where near as finicky. And flexible pla printed fine. I am still using the same one for the last three months, and its double sided.
PEI is not the same thing as Buildtak.
