Nice job on adapting the endmill grinding fixture, Jim.

For others that might be following along, the General-type fixture has been
available for decades, and one of mine is a Craftsman, but they're still
being made.. and copied, presumably in China sweatshops for the tool
importers

http://www.drillspot.com/products/57...ner_Attachment

Those Bison chuck prices range from almost $100 to over $100 per inch..
ouch, that's just extravagance for a hobbiest.

Your modification recommendation for the clamp on the General fixture would
be a very good addition.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"Jim Wilkins" wrote in message
...
...
If the fixed point on the General fixture was on top where it could be
adjusted easily, that would be tits.

Looking at a General No. 825 from the 60's, if the pivot for the hold-
down clamp was moved further outward to reduce its angular rotation, a
'billet' clamp could include a top finger. Unlike the bottom one the
contact point would shift lengthwise with drill diameter.

The original Drill Doctor works well enough for me, but I've also been
considering putting the General fixture on the surface grinder to use
its XYZ motion, and making a sleeve that fits onto Darex chucks with
an alignment wire or plate across the end.

With a conventional grind on a drill, maintaining the narrowest chisel
point
(at the web) is the key to having a drill that cuts and feeds easily, and
a
drill that may only rub a hole in something if enough pressure can be put
on
it.

I use a small parabolic drill first to avoid fussing with split
points.

I've pondered how to make a round drill holder resembling a drill chuck
for
quite a while,

Bison makes 6 jaw chucks for tool grinding. Not Cheap!!
http://brassandtool.com/Chucks-Lathe.html

The Darex chucks aren't bad as long as you don't tighten them more
than necessary.

I made this 5C collet nut for sharpening large drill bits in an end
mill grinding fixtu

http://picasaweb.google.com/KB1DAL/T...98039281271986

The 1/2" insert centers S&D drills by the shank. The back relief
setting grinds a 120 degree point. A long bit will clear the side of
the mag chuck while the base is on the poles. I've been downstairs
trying it and clearly need to make a spanner wrench to tighten the
collets more.

Jim Wilkins