Since there have been a lot of questions about a locking nut for the banjo, headstock or tailstock on the G0766, and only one comes with the lathe itself........
I went to Grainger and ordered some that will fit........unfortunately, everywhere you look they are a bit pricey, and I went to our local hardware earlier today while I was out, and they did not carry the right size which is M18x2.50 .....so I went ahead after doing a quick google search for them and the cheapest is a pack of 25 for 13.05 + shipping.
https://www.grainger.com/product/GRA...Locknut-26LJ91
Just in case anyone else was interested. Way more than I need, but at least I will have a few extra on hand! After estimated shipping costs, they will come out to be about $1.00 a piece.