ThreadExpress, a shop made thread milling attachment.

[Mark Presling]

Back in 2024, I watched a series of YouTube videos by Cliff Hall. Cliff is a toolmaker from New Zealand. Cliff runs a YouTube channel called Threadexpress. He was disclosing some details of a shop made thread milling attachment that could be used on a Bridgeport style milling machine or a horizontal mill. The machine was capable of cutting both internal and external threads in a wide range of pitches. He agreed to let me have the full set of sketches of the mechanism and I in turn agreed to provide him with a set of 2D drawings and a fully rendered 3D model.
In order to do this accurately, I needed to build a new version of Threadexpress which would be called V3.0. This new version of Threadexpress is now complete and I have been using it to cut some threads on project parts. It has some unique features and best of all, you can cut custom thread forms with just a simple shop made flycutter. Because it is manually operated via a 4:1 gear reduction to drive the spindle in which the workpiece is held (in either a 100mm 3 jaw chuck, or an ER32 collet chuck) it is possible to cut threads very close to a shoulder.
I have made a 14 episode YouTube playlist for anyone who might think about building one and Cliff Hall has the full set of 41 drawing sheets available for download via a "buy me a coffee" link on his website https://hallmarkdesign.co.nz/new-threadexpress
The playlist includes nearly all of the machining and finishing processes and also a demonstration of the thread milling process. The first video in the series outlines the scope of the project and a breakdown on the costs and materials required.
Enjoy!
https://www.youtube.com/playlist?lis...yCXoRFvYWKFJ-n