The Instructable gives details about making a pair of internal/external metric threads in 1" (25mm) diameter aluminium tube/bar. It covers the calculations, the preparation of the cutting tools and doing the whole job. I have a Myford ML10 with a metric leadscrew, however only a couple of steps will be specific to that lathe.
Step 3 explains exactly how to prepare the bar and tube with virtually no mathematics involved. One problem, I am a complete novice, so there are probably errors and examples of poor practice - be warned! I hope that comments from other people, will highlight these so I can correct them.
- Choosing a pitch
- Mathematics - deciding on the thread size and exactly how to move the cutting tools, etc
- Thread cutting calculations without mathematics!
- Preparing the bar for external threading
- Grinding an external HSS threading tool
- Setting up the lathe leadscrew and backgear
- Cutting the external thread
- Grinding an internal HSS threading tool
- Preparing the tube for internal threading
- Cutting the internal thread
- Final fitting