Partially Solved Can't Seem to Get Z-Screws right...

Me again...

So I thought the videos at the top on rotating the screws were very helpful, but I'm somehow lacking the right touch to make it work.

I have adjusted them, measured and made sure the x-axis is parallel to the plate, but when I run the G29, it will do the left and middle just fine, but when it gets all the way to the right, the switch releases too early. So I stop, adjust, and it happens again. over and over.

I'm going crazy. This is happening to both of my printers.

 

The weight of the motor on the right gives it a see saw effect where the left side raises up a bit. You can combat this by biasing a bit towards the right side, or add something like a "penny box" to the left to give it a counterweight

 

I'm assuming by "bias" you mean raise that side up a little higher, so that is what I did. However, when I started by print, it was still printed slanted (the left side wasn't extruding as it was touching the bed, and the right side was too high for a good print). I was able to pause and adjust mid print, and all seems to look good right now.

Is there anyway for me to know if it will do that prior to starting a print job?

 

Watching the G29 response codes in terminal will give you a good indication of how well the autoleveling is working

 

Yes Mike - I do that several times before I print. I get out a ruler and measure the bars. In the G29 - I usually get readings closer to -0.2, 0.0, 0.2. Yet when I go to print, it still is off.

 

Got a picture of a first layer being placed?

 

I have a video!
https://drive.google.com/file/d/0B1W8HHxhuFrrVzYtSjJ3WS1jN00/view?usp=sharing

 

Well you need to reduce your Z offset. It also looks like the switch on the left in the video (right when facing front) is not making contact with the idler above it

 

I'm having this same problem. I've upgraded my z axis using the Robo3D acme threaded kit several months ago. The problem existed to a small extent with the old setup, I'd have to turn the right threaded rod maybe 1/2 or 1 full turn lower, but it's drastic with the new rods. I have to have the right side ~ 2-4 mm lower compared to the left to get the G29 auto level to touch down on the right side.

The problem is, the G29 doesn't effectively calibrate the bed level and I'll end up with a first layer that might be .3 mm thick in the middle, .15 mm thick on the right side, and .4 on the left-- thats IF it sticks on the left side and doesn't jam the print head on the right.

This problem seems to be getting worse recently. I'm going to try replacing the linear bearings on the Z-axis guide rods to see if it helps to straighten things out.

This is the only thread that I could find on this topic, but I'm sure there are more out there. If anyone can point me to a solution, or at least other ideas to try, I'd appreciate it.

Thanks