New chuck adapter for SB 9

[mzvarner]

When you flip the plate around, it will only thread on so far leaving a gap between the spindle shoulder and the plate. This means
the plate will likely be spinning crooked. The spacer enables the plate to snug up to the spindle and run true

Ah! Got it. So obvious now that you say it! Appreciate the input. Hoping to knock that out (at least make progress) tomorrow