grinding a radius on an end mill

[Sblack]

I need to obtain an end mill that cuts a 1/8" radius (inner radius, like a fillet, not a round over if that makes sense). I have not been able to find any reasonably prices end mills so I was wondering it that would be a straight forward thing to modify an standard end mill. I have just obtained a single lip cutter grinder (British clone of a Deckel SO). Would that do it? Has anyone done this before? I was even thinking of trying it by hand on a 2 flute end mill using a radius gauge, but that seems a bit crude. Any suggestions?

thanks

Scott in MOntreal

 

[Karl_T]

I buy them here
https://www.the-carbide-end-mill-store.com/CornerRadiusEndMills.html?i2511035:page=6

You could fake a two flute HSS in, but crude like you say.

 

[Billh50]

Always did mine by hand on a bench grinder with a radius gage.

 

[Bob Korves]

Like BillH50 said. The end mill can be radiused offhand on a grinder, and then clearance is carefully added behind the cutting edges to keep them from rubbing. I have a pile of ball end mills that someone has done that to, probably after a corner was chipped off the square cutting end mill. If the end mill is only slightly chipped off at the corner, a smaller radius can be made in the same way, which will leave a nicely radiused corner on the work. Don't throw a sharp end mill away just because it has lost a chunk off the corner!