Pergo Bed Stiffeners

This may work on printers other than a Robo3D/R1/R1 Plus
The 8mm rod(s) are 24 mm shorter than your glass length.

** Warning remember your working with glass! be sensible in the amount of correction you try to make. If you apply TOO much shim you could break the glass. I some cases the glass is between $30-$50.00

When I created my 330mm Y Rails upgrade for the Robo 3D
http://www.thingiverse.com/thing:1154745
I learned that my bed glass was .02 mm lower at a certain point that at other points.

When your auto leveling a larger printable space it's expected that you will find larger variations that when using a smaller area. I personally have my auto level routine in the firmware reaching out to points at 5 mm and 305 mm when it auto levels the Y area (this is a firmware config change).

Ok now for the fix.
If you did the 330mm Y rail upgrade, you will have the old standard length rails. I created the (printed in red in the pictures) rod holders to use these standard length