I was looking over my junk pile and it appears I have enough linear hardware for the first CNC Hotwire Cutter.
I cut out some test holes for mounting out of acrylic and hardboard.
The longer rails are 15.25″ x 10mm, bearing OD 12.95x12mm.
The shorter rails are 8mm x 33cm, bearing OD 16x25mm.
The 12.95mm hole fit snug but the rest are a bit loose so I will need to shrink them.