[maker of things]

I hear ya. I drilled a hole in the drill press the other day and I was so bored (pun intended) thinking "why do I have to be here for this?". Hoping my 0704 can handle the saddle. I haven't found anything substantive that indicates if one shape is more effective than another for the oil grooves. I kind of doubt that the "E" shaped groove will actually dispense oil across the ends vs just filling up with swarf. I'm thinking maybe the subtle "S" shape or maybe even the simplicity of "/" with the feed in the middle. I have no evidence or proof, but it just feels to me like channels perpendicular to travel would be perfect for trapping junk, and once filled not distributing oil.

[Bubba]

Jon,
When I went through the same thoughts many years ago, My Mentor lent me his machine tool rebuilding book. To make a long story short, one of the areas covered was the shape of the oil grooves. They recommended a "Z" pattern and that is what I used. Seems to have worked very well.

[maker of things]

Jon,
When I went through the same thoughts many years ago, My Mentor lent me his machine tool rebuilding book. To make a long story short, one of the areas covered was the shape of the oil grooves. They recommended a "Z" pattern and that is what I used. Seems to have worked very well.

Good to know.

[Topdecking]

If I remember correctly there is a good reason for the Z over the H pattern.
In the H pattern when the platform crosses longitudinally (on an H, being from left to right), friction will push more oil into the right arm, it gets this by boundary layer effects, and the left arm starves.
Moving to the Z pattern reduces this slightly and breaks boundary layer effects.