You will need:
4 Misumi 90 degree brackets (90-D-BRACKET http://store.makerstoolworks.com/90-degree-extrusion-bracket/)
1 Mendelmax 1.5+ y rail and 4 cars: (http://store.makerstoolworks.com/motion/mendelmax-1-5-y-axis-rail/)
An A0-101 style solid middle heated bed plate (If you have an A0-100, ebay has easily modifieable ones, though shipping is a pain in the ass)
The printed y axis endstop mount and belt piece
the existing Y axis belt and y axis rod mounting hardware
your existing heated bed and mounting hardware (screws and springs, etc)
an additional Y axis 20mm extrusion, 380mm long
4 Flat Head Cap Screws, M5-12
5 Button Head Cap Screws, M6-12 (-16 possibly)
8 Button Head Cap Screws, M6-10
10 additional t-slot nuts
The rail is pretty much perfect as is lengthwise, it will rest on top of the existing lower structure. The advantage to this modification is less mass on the y Carriage (the standoffs and the lower assembly), less possibility of rod defliction theoretically resulting in better repeatability. The bearings seem to move faster than the origional igus style ones too, but that could just be because I have a used machine and these are new bearings.
The trickiest part is the modifications to make your heated bed plate. I followed the lulzbot diagram to make the side cuts to reduce mass. To attach the Y belt, you end up using zip ties and attaching the belt against it’s own teeth. I was skeptical at first, but it seems to hold. There is an alternative screw clamp variant of the belt attachment available, but it seemed fairly flimsy as is, so I ende dup using the one attached instead. I haven’t got everything into the machine yet, but once it’s in i’ll post more pictures.
ohmeye_mm2_endstop_y.stl (40.6 KB)
beefy_y_belt_block3.stl (62.4 KB)