stop warp FRAME i3 compatible

I like this design, but I had problems with warping (print with cheap ABS).
I was a little modified design and the result is 90% better.
Remixed from: http://www.thingiverse.com/thing:971110

2016-04-21 add z-axis top end for 625zz bearing
1x 625zz bearing
5x M3x16 screw
5x M3 nut
5x M3 spring washer
5x M3 washer