[Joe Miranda]

OK, I have an older lathe, probably '99 vintage. Can anyone help me with how to create a radius in the bottom of a groove. I have tried everything I can think of to no avail. I have a .108" wide grove with .054" radius in bottom of groove and I am using a .0625" radiused grooving tool.

[ZZZZ]

How about if you plunged down the center line of the groove nearly to the bottom to remove most of the material, then down one side with a radius to the center at the bottom, then down the second side with the radius at the bottom and back out the first side. By choosing the right numbers, you might be able to get the last line-arc-line move to be to the finish size.

If you try it, let me know how it works.

[elfrench]

Grind a tool with the .054 radius. Depending on your tolerance requirements and material, it shouldn't be too difficult. You didn't say if the groove was located on the side or the face. It will make a difference in the reliefs needed on the tool.

[chuckorlando]

It's hard to put a smaller radius in using a larger radius tool. I would just grind a tool and plunge like mentioned.

[sportybob]

Hi Joe, don't get me wrong here, but a .0625 radius tool will not fit into a .054 radius "hole" it is too big. ( 0625 is larger then .054) Your need to either have a .054 radius to and "plunge" in to the grove. of a smaller radius tool and " plunge and move over".

I could make some other references, but , a .500 bolt does not fit in a .498" hole. ( nor does a .250" bolt fit a .500" hole) ; - O

R=1/2 D ( sorry, but it is true.) " blame that "smart ass" Archimedes"

sportybob

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