Back from vacation and I am itching to get into the build.
The Huffy 20" wheels come with an alloy insert already pressed into the hub and sealed bearings are then inserted on each side. As can be seen in the first photo, the insert and bearing sits proud of the surrounding hub so the crush plates on each end of the hub need to be relieved that 2.2mm. Using a marker pen I roughly traced around the hub and then placed the disk on the 3/8" thick 6061-T6 before drilling and screwing on the rotor. Lines drawn between the screw holes show exactly where centre is. I used a 1/8 bit to drill the centre hole perfectly. The alloy insert is exactly 40mm and I just so happen to have a 40mm forsner bit which I used to make lightening holes in timber earlier. I have no lathe, nor a mill so have to make do with what I have at hand. So drill press and forsner bit it has to be. It took ages to mill down the 2.2mm.
