On 10/3/2010 8:45 PM, DoN. Nichols wrote:
On 2010-10-03, wrote:

"RS at wrote in message
...
While your question is more one of how can you make a buck off 300
lbs. of dull end mills, I for one will choose a reground end mill most
of the time. I have several reasons for this.

If I am milling on the edge of a piece of material it makes no
difference to me if the end mill is .005 undersize.

[ ... ]

The issue I see is that if you use an edge finder or a dro, you've got more
math to do. It's too easy to screw it up. But, resharpened mill certainly
have their place and value, just not so much in a production or precision
situation. What's the cost of a part that needs to be fixed or pitched?

And -- if it is a three-flute or a five-flute end mill -- how do
you measure the diameter?

Yes -- there are special V-anvil micrometers for such
measurements, one for the three-flute and one for the five-flute. Do
*you* have them? (I do -- but I collect tools, so I perhaps don't
count. :-)

But these special micrometers are expensive too -- especially if
you need to purchase them new. :-) (Unless you need the three-flute and
the five-flute versions to measure ground cylindrical surfaces for lobes
taking them off truly cylindrical. A standard micrometer won't see
these particular errors.

Of course --you could skip the edge finder and find your zero
with the old cigarette wrapping paper trick instead, which would include
the change in diameter in the setting -- for that *one* edge. :-)

Enjoy,
DoN.

When I used to have to use regrinds with odd numbered flutes, I'd clamp
the shank in a V-block on the granite table, put an indicator on the OD
of the shank, then pick up the reground edge with the indicator which
would give me the difference in the radius. Not a problem if you didn't
need .001" accuracy. If you did, use a new end mill.

David