How to radius an outside corner edge?

[JMI]

Hi All,
Just started work on the "Miser" Stirling engine. The drawing calls for some of the parts to have the edges of some parts rounded to a specific radius, for example, .062.
How is that accomplished?

TIA

Jim

 

[kvom]

1/16" corner rounding mill.

 

[ghart3]

Jim, don't recall where that radius is called out for. If it is a for appearance only radius on a flat or round surface this can be done fairly easy with only a little practice. For a flat surface a file will work good and will work in the lathe for a round surface using lathe bit or if your carefull and follow safe procedure such as rotating chuck by hand while filling.

Make a flat at 45 degrees that is about .050 inch wide. Then make another flat at about 22 and half degrees on each side of this 45 degree flat. This will be close to the 1/16 radius and will take very little filing or sanding to make a very close to a true 1/16 radius.

If this is confusing, say something and will do sketch.
Gary

 

[shred]

A form tool would also work for lathe parts. 1/16" radius would be a 1/8" diameter hole. Drill such a hole in some drill rod or tool blank. Grind down to the hole. Apply to work. Harden if needed.

 

[JMI]

Thanks guys. I discovered the rounding mill bits mentioned by kvom. That is the way to go, I think.

Jim