This pre-made spindled
chuck backplate will help you along!
It is made from
12L steel and is 1-1/2 inches long.
Spindle end is
threaded 1 X 8 threads per inch, (1 inch of threads).
The 2 inch diameter
X 1/2 inch thick backplate is drilled and countersunk for
3 #8 woodscrews, (not included).