Thread Cutting Fixture - Stop Struggling

[Lets Roger That]

I finally made a thread cutting stop. No more struggling.

[DIYer]

Thanks Lets Roger That! We've added your Thread Cutting Fixture to our Lathe Accessories category,
as well as to your builder page: Lets Roger That's Homemade Tools. Your receipt:

Thread Cutting Fixture by Lets Roger That

tags: lathe, threading

[Toolmaker51]

Single Point Threading Stop. That's a worthwhile project and nicely done video. South Bend and many lathes worldwide use that with total success.

(1) Manufacturers of some lathes add rather comparable action into large machines, with one advantage; the stop works to set inbound travel repeatedly, versus retracting cross slide. Set for job at hand, there's no reading of dial at all, beyond a glance on approach.
The operator translates that into an "O'clock" position and tactile response. Feed is by compound, while carriage returns to start, purt-near doubly efficient.
(1) Within dial is difficult on indirect reading machines, purely due small diameter to house sturdy parts. Hence the clamp-on stop, very expedient.

(2) Some have a T slot finger & pin (outboard between carriage & cross slide), a mechanism within dial, or a travel rod. Milling a slide presents rather serious challenges.
One solution is a pair of stand-offs supporting a rod. Flat one side for a set screw, which is in a spool. It contacts a hard stop. Very similar arrangement found on most milling machines. Deciding where to mount hard stop/ adjustment portion is mostly a question of convenience.

(2) The option/ addition I'd consider somewhat combines those.
Put a hole through clamp on bracket (type in video), a short flatted rod attached to slide, with a set screw collar.
The advantage becomes apparent as threads deepen. More turns are needed to retract fully, meaning that version is set for clearance to finish the job. If moving out farther is needed, regrinding bit, something is loose, any unplanned issue, the retract stop may have to be removed and reset.

The advance version stop does away with that.
Combining them (retract and advance) cures the tougher single point job all in one tool; ID threading from down hole. That's always touchy. This applies equally for grooving or parting multiple pieces. A screw stop offers accurate adjustment.

If any one needs a sketch, I'm willing.