Saddle Lock for the ML7 Lathe

The standard saddle lock on an ML7 lathe was a 1/4" Whitworth bolt which was tightened by the use of a spanner.

This modification involved the manufacture of a short handled lever to be fitted as a permanent fixture to the lathe, this would make searching for the spanner a thing of the past and make locking and unlocking the saddle a much quicker operation.

Here are pictures before and after.

Original Saddle Lock

New Saddle Lock


To reuse the clamp mechanism itself, the correct thread had to be used. This was a BSF thread of 5/16th diameter with 22 tpi. A brass washer was used under the clamp handle to set the lock and unlock positions so that the lever would be out of the way. The photo above shows the clamp in the locked position. Unlocked, the lever turned about 30 anti-clockwise.



A similar handle was manufactured for the tool-post bolt. This was designed to work with a quick change tool-post from RDG tooling

The handle was kept short on purpose to avoid it getting in the way.

Tool post locking handle


Since making the saddle lock is was found that the lever got in the way if the top-slide was rotated anti-clockwise the full amount and the cross slide is wound in. A corner case situation but worth knowing. This probably explained the design of the original Myford solution.