I have printed out the very useful dial gauge mount for the carriage and used it to try to get my bed more accurately leveled, as I was having some problems using the paper method and it was affecting print quality. More specifically, I could never get the back corners of the bed to have a similar amount of friction on the paper/feeler.
What I found out is that even when I have the back-left fully loose (to minimum where any further turns would cause the spring-loaded screw to come loose), and the back right side is fully tight to it’s maximum; there is still ~0.7mm of difference between the two corners. The front corners do not have this problem at all and can both be adjusted to ~0.00mm to match either one of the back corners, BUT NEVER BOTH.
So my problem is that because of some issue with either the aluminum base, build plate, or plastic clamps not being “true” there does not seem to be a way for me to get all the corners to be at a height at or near 0.00mm in relation to each other.
I have tried shimming the back corner pieces and also tried longer M3 screws, but it does not seem to help as the springs seem to be meant for the original size screws.
Does anyone have any ideas on how I might get an actually leveled bed?
I had similar problems on my Taz 2.1. In my case, it was inconsistent heater pad thickness at the corners that rest on the adjusters. I first shaved off some of the rubber material to even them up but, eventually, I just cut the corners off of the heater mat so the glass set on the adjuster directly. I did have to shim the bed with washers to raise it enough to be clamped tightly by the corner mounts.
I also installed: http://www.thingiverse.com/thing:627331 I provides more adjustment throw at the corners at the expense of a few mm of build height. Plus tool-less adjustment!!
DISCLAIMER: Cut the heater mat at your own risk. If the heat traces are in the area you are cutting, you will likely destroy the heater mat. I was able to see the heat trace outline in my mat and was fairly certain there was not anything close to the corner of the bed.