I have decided to embark on upgrading a mutant standard 4848 to a true* 4896. I hope this will not only help me but for future users. If you see something that is not correct or better parts please speak up.
Once this is done i might have wasted more time and money than going with an upgrade kit from AvidCNC.
My mutant 4848 is comprised of rack, pinion, gantry parts from CNCRP and a welded base frame without cross members. I will be using extrusions for the new 4896 base and reuse whatever exist to keep the cost down, your cost could be lower if you have a true 4848.
DIY Parts
All parts are listed as if a new base was to be made without reusing existing hardware (ill remove the extra parts for my personal b.o.m.)
2 X 108" (Y Axis) 1545 profile 10' triple rail McMaster $234.98 X 2
9 X 54” Cross members 1530 profile 10. 10' & 6' Duble rail McMaster $117.85 X 4 $60.04 X 1