Of the two Jacobs chucks that came with my lathe, only one fits the spindle threads. One is a Rigid brand, which may have come from a drill motor; It does not fit, FWIW. I set up the Unimat SL1000 for drilling with the machine "vice" to hold the part to be drilled. The drill bit will have to get between the barely open jaws in order to do the work. It will be tight but looks doable. I won't be able to get to the actual drilling for a week or so, but will report back on how it works out. Cheers, gents.