The threading attachment mounts to the outboard end of the spindle by means of a collar and set screw and functions in the same way the traditional Holtzapffel lathes did by engaging a threading chaser into a threaded bobbin of the same pitch.
The attachment comes with four sets of thread pitches or threads per inch (they are 4 tpi. , 8 tpi., 12 tpi.,and16 tpi.) and is capable of making one, two, three, or four lead threads which gives a wide variety of threading options. The thread chasers are made of brass and the attachment holder, collar and four threaded bobbins are coated in black oxide to prevent rust. The lever is used to engage the thread chaser firmly into the bobbin and hold it while it is being locked down by the cap screw.
——————- $420 —————–
To cut a thread, the Drilling Frame is used with a 60-degree cutter held in a 3/16″ fly cutter holder. The 3/16″ fly cutter holder is supplied with the Drilling Frame or can be bought separately.
Another option is to use a 60-degree thread mill cutter held in a 3/8″ end mill holder. Both the thread mill cutter and end mill holder can be purchased from Lindow Machine Works.
Note: end mill holders are based on the 8MM collet size
The Threading Attachment can also be fitted to most MDF rose engines.
A replacement 3/16″ end mill holder $40
60-degree thread mill cutter $40
3/8″ end mill holder $40