Massive Mendel is a standard Mendel with 12mm x,y,z-bars. The threaded rods are left at 8mm. Here are only the parts which differ from the standard mendel. Included are also the changed y-chassis dxf, a STEP file with all parts and the original Solidworks 2010 Files. The x-chassis is also heavily modified, so there's maximum room for hot ends.The reason for this probably overkill solution is the weight of my 8mm thick heated bed which is over 1kg. I calculated the y-bar deflection to be around 1mm with 8mm rods, so Massive Mendel was born. With 12mm bars the (calculated) defelction is below 0.1mm.It's pretty much assembled the same way like a mendel. The clearance below the y-chassis gets pretty small, I had to file away some threads from the rods.