The holes are laser cut, and since this is not 100% accurate and can leave a small burr, they need to be drilled out to the correct size.
- The small disks are the same.
- The 4 holes are designed to be used with 12mm bolts, and so should be drilled out to 12mm
- The central holes should be a press fit for the bearings, and will need to filed, sanded or reamed until the bearings fit into them
- The bearings should not fit loosely, but so so tightly that they are not held firmly in place
- The large disks:
- One large disk has a central hole, and 4 mounting holes. The mounting holes should also be drilled out to fit 12mm bolts
- The other disk has 8 small holes. The 4 larger holes should be drilled out to 12mm
- The 4 smaller holes are for jacking bolts, which are essential when assembling the rotors
- These smaller holes are designed to be tapped out to fit 10mm bolts
All holes should be smoothed after drilling using a beveled countersink bit.
The plates should be cleaned (30% pool acid for 15mins is one way), degreased, and painted with a metal primer and overcoat.
The face on which the magnets will be mounted does not need to be painted, as it will be coated with epoxy.
After mounting the magnets, all exposed metal should be primed and painted.