TAZ 6 bed leveling - Auto vs Manual

As I was going through the TAZ 6 auto bed leveling, the firmware returned this data

< Bed x: -9.00 y: -9.00 z: 1.469375
< Bed x: 288.00 y: -9.00 z: 1.519375
< Bed x: 288.00 y: 289.00 z: 0.850625
< Bed x: -9.00 y: 289.00 z: 1.685000
< Eqn coefficients: a: -0.001320 b: -0.000760 d: 1.671742
< planeNormal x: 0.001320 y: 0.000760 z: 1.000000

Based on the 4 “z-axis” values in the above, it looks like the measurement seems to be in 1/8 of a .001 millimeter jumps, in other words, accuracy of .000125 mm. The values vary as much as .83 mm from each other.

So I was wondering whether leveling the bed on the TAZ 6 manually made any sense.

    1. What is considered a good bed leveling accuracy for a manual bed leveling system?
    1. Is the TAZ 6 capable of being manually leveled? If it could, I suspect it would either just be a little more or less tight on the appropriate leveling washer, or else some small “shims” in that corner that needed it. Perhaps the metal plate holder for the bed should have some metal angle brackets or similar on it to keep it from flexing (which it clearly does).
    1. Would it produce a better print than just doing an auto-leveling?

I don’t own a TAZ 6, but on my previous printer which auto-leveled itself through an induction probe it made a difference to start with a level bed. Since there was no mechanism to level the bed, I used aluminum duct tape as shims.

There is no mechanism on the Taz 6 to level the bed. The corners are fixed in alignment. That being said the plate is usually pretty flat, and the corner thickness is usually pretty consistant, so it should be pretty flat already. You could convert a 6 back to manual leveling if you built it some retrofit corners and made a new motor mount with z alignment target and endstop, but that would be a lot of work.

Make sure your y-rods are level relative to each other front to back. If not your bed is saddle shaped and that will cause bed leveling issues. I explain this here:

https://forum.lulzbot.com/t/leveling-the-y-axis-getting-rid-of-high-low-spots/3706/1