Lathe: Compound Lock and Gib

The compound slide gib is not nearly robust enough for the forces you can see, especially when parting and threading. I've seen the whole compound rotate over on the gib when the parting blade jammed. To remedy this I added to both add a gib lock and to add an extra gib set screw.

I removed the top of the compound and clamping it in the mill and drilled and tapped two extra holes located exactly between the existing set screws. After modifying the gibs (http://benchtopmachineshop.blogspot.com/2015/01/lathe-gibs.html) I put a dog nose on a M4 SHCS and installed it in the middle set screw hole. Now the compound has more support overall and I can easily lock it in place.

Extra gib set screws with the gib lock right in the middle.