I’m beginning to think I either have a lemon or the two-screw Taz 6 is a fundamentally broken design. 
When I first bought this printer a month ago, its z-axis wedged up fairly quickly. I carefully followed the x-axis leveling procedure and ran a few more prints through it. Today, it’s all wedged up again.
The set screws on the steppers seem tight. I’ll go ahead and level the x-axis again. Does anyone have any suggestions for fixing this problem so it stays fixed? I elsewhere someone saying they’d printed some alignment tools, but couldn’t figure out what they were talking about.
I bought this printer to make some big parts and I don’t trust for a moment that it’s going to run them to completion.
Thanks!
Z axis jamming is not normal, usually it involves either an x axis already out of sync, a loose z motor coupler, or a broken z motor coupler. In rare cases it can be a lower z motor mount down too far on the frame. Here are the troubleshooting steps.
- Check the top of both leadscrew where they enter the upper leadscrew bearing. They should both be up nearly flush with the center hub, the same on both sides, and you should not be able to manually move either leadscrew up or down in the bearing socket.
- Check both motor couplers. At least one of the two setscrews on the top and bottom of the coupler should be down and tight on the flat spot on the leadscrew and the motor shaft. All 4 screws should be present.
- Check the leadscrew couplers for cracks, also see if the x motor shafts look intact. a rare failure mode can involve a cracked z motor shaft but that was mainly taz 5s that are affected.
- With the printer off and at z0 home, measure the distance from the left leadscrew nut bottom to the top of the lower z motor bearing. Measure that same distance on the other side. It should be identical. If it isn’t, manually turn the leadscrew until they match.
- Check that all 4 bed corner washers are down, tight and not wobbly.
Clean the horned nozzle really well, making sure the tip is shiny for good metal contact, a red scotchbright pad is good for this, never ever ever use a wire brush
- Now re run the bed leveling routine and print the bed leveling pattern to make sure everything looks right.
You should be set then. If not, there are a few other things to try. You may also want to call support as well at that point.
I had this issue on occasion. Turns out on my machine the Z axis couplers where putting pressure on the rod as if they tightened the couplers down before tightening the motor down. In the end loosened the 2 set screws on each coupler and you could here it snap up (taking pressure off the system) and then simply tightened the screws down again. Been running my machine for years since without a Z axis issue.
Note there are 4 screws total on each of the couplers, you have to loosen both on one end, then just wiggle it a bit if it does not move up or down on it’s own. Tighten, then do the same on the other side.
Hope this helps.