How to make a radius tool for the lathe?

[Janderso]

What is the best way to fabricate/grind a 5/64" radius cutting tool?
I want to duplicate this part the easy way.
Thanks for your help.

 

[Winegrower]

Humm…don’t we all? I take my radius gauge and blue the end of a HSS stick, scribe and grind to the line.
I have a feeling this is not the easy way.

Edit: Actually I have a reasonable selection of Kennametal “top notch” inserts and a couple holders. The inserts are either rectangular grooving or radiused. So if the radius was not 5/64” exactly, I would just pick the closest, and done.

 

[JimDawson]

Use a 2 flute ball end endmill. That's normally what I do for small radii.

 

[Jimsehr]

What is the best way to fabricate/grind a 5/64" radius cutting tool?
I want to duplicate this part the easy way.
Thanks for your help.

Jeff
carbide or hss ?
I can grind one in about 5 minutes. Email me your address and I’ll send you one.
jimatcf@hotmail.com
Jimsehr

 

[mmcmdl]

Hit it on a grinder . Check with a gauge if you need it to be close to perfect .

 

[homebrewed]

If you have a rotary table+chuck and a mill there are serveral ways to go. Straight 5/16 end mill: orient the RT so its axis of rotation is parallel to X. Plunge the EM into the corner then slowly turn the RT. Ball mill: orient the RT so its axis of rotation is parallel to Z. Plunge and rotate the RT.

So I guess, not having done either approach. But they look viable enough to me to try, if I need that shape.

If you have an RT you know this, but just to say it: you don't want to climb mill when using an RT. Well I don't, anyway .

 

[Janderso]

Jeff
carbide or hss ?
I can grind one in about 5 minutes. Email me your address and I’ll send you one.
jimatcf@hotmail.com
Jimsehr

HSS.
I guess the best way to do this is grind to width then round the end.
I was fishing for some wise old method of dialing this in.

 

[Janderso]

If you have a rotary table+chuck and a mill there are serveral ways to go. Straight 5/16 end mill: orient the RT so its axis of rotation is parallel to X. Plunge the EM into the corner then slowly turn the RT. Ball mill: orient the RT so its axis of rotation is parallel to Z. Plunge and rotate the RT.

So I guess, not having done either approach. But they look viable enough to me to try, if I need that shape.

If you have an RT you know this, but just to say it: you don't want to climb mill when using an RT. Well I don't, anyway .

I have a 320# rotary table that sits on a shelf and gathers dust.
It’s probably only 90# but it’s awkward as hell to move.
I find reasons not to use it.
I think we’ve all learned the climb milling lesson on an RT

 

[Jimsehr]

Jeff

Another way to make the radius tool is to turn a round cutter too size like you did to make the .210 dia form tool last month.
Jimsehr
just remember without clearance it will turn but not face unless you grind some back clearance.

 

[Shiseiji]

What about a router core box bit?