Making a swing type threader similar to John Stevenson’s has been well up on my to do list. Mine uses the Vertical Thread holder for the TNMC 43 NV inserts. I use both the 43 and 32 size vertical inserts and like them. Initially I was inclined to do one on a dedicated tool post rather than on the Quick Change Tool Post. I may still go that way. Using this type holder on a small 12” lathe that is only 1.063 from the top of the cross slide to spindle axis is a little cramped for space. This design uses the 3/4" size tool holder. I prefer the 1” holders but that will have to wait for now. Here is my first go at the Swing Threader.
This shows the back view of the threader. Bolt placement needed to clear the dovetail of the QC Holder. A longer Shoulder bolt will be installed when it arrives.
View showing the parts.
Parts are fitted pretty close but I will add some sort of indexing. A center punch prick on the washer was used to upset enough metal to take up the small side to side movement. This is for initial test run. I am still thinking on whether to install a brass or Teflon tipped adjustment screw, a key, or a vertical bolt or go back to the mill and skim a few more thousants from the threader body.
This shows the back view of the threader. Bolt placement needed to clear the dovetail of the QC Holder. A longer Shoulder bolt will be installed when it arrives.
View showing the parts.
Parts are fitted pretty close but I will add some sort of indexing. A center punch prick on the washer was used to upset enough metal to take up the small side to side movement. This is for initial test run. I am still thinking on whether to install a brass or Teflon tipped adjustment screw, a key, or a vertical bolt or go back to the mill and skim a few more thousants from the threader body.