Center of plate higher than sides?

Support&troubleshooting Zortrax M200
#1

So,

When I first go the printer last week I did auto calibration and I got numbers in 0.0 to 0.1 range for all points on the plate.

Thinking I can improve (doh!) I tried the alignment process again and while I can get the back and front to be within 0.1, the middle now registers anywhere from 0.3 to 0.6 no matter what I do.

Did the plate warp? What's going on?

I heard that manually calibrating with a sheet of paper just barely catching onto the nozzle when plate is all the way up is the way to go. Should I do it this way?

Also, what is the truly acceptable margin I should be OK with here?

Thanks!

#2

Remove your perforated platform and wipe down its underside with some acetone. Over time, melted plastic creeps through the perforations and gets under the platform, pushing it upwards. Since the vast majority of action occurs in the center, that's the first place the issue manifests itself. That said, your raft should mitigate reasonable variations in level, so I'd say any truly acceptable margin is one where your rafts aren't peeling from the platform due to warping.

#3

Check this:

Straightening Perforated Plate

Cleaning the Platform

#4

Thank you both!