DIYbanter - View Single Post

Tom Gardner[_6_]

On 5/15/2012 8:35 AM, wrote:
Background:

A long time ago I bought two bench grinders from Grainger. They are 8
inch belt driven grinders. And I like them because they are slimmer
than ones with a motor between the two wheels. And i also like the
size. 6 inch wheels seem to be a little small. I also have a 10 inch
grinder so I am not lacking for grinders. The 10 inch one has two
regular wheels. One of the 8 inch ones has a wire brush and a
abrasive cut off wheel. And I just made another stand and plan on
that 8 inch grinder having a fine wheel and a rubber contact wheel
that uses sanding belts.

I have had a General drill sharpener fixture for ages and decided to
figure out a way to use it with the fine wheel on the 8 inch grinder.
So I was rooting around on the internet looking for instructions for
the General fixture and ran across several videos of how to grind
drill bits by hand.
I can grind drills by hand if they are not too small. I taught
myself. Anyway I watched a couple of the videos and saw that the
videos show a somewhat different way to sharpen drills.

When I sharpen drills I start grinding on the heal and finish at the
cutting edge. Both videos showed the grinding starting at the cutting
edge and ending up grinding the heal. So I am curious how most people
grind drills by hand.

I mounted the General fixture a bit different from the instructions.
It is rotated 90 degrees from the usual position and the cutting is
done on the outside of the wheel. So the drill is in about the same
position as it would be if sharpening by hand. Somehow grinding on
the side of the wheel seems wrong. This does have the advantage that
any grind marks are perpendicular to the cutting edge. Not really a
big deal as fine stone is 100 grit and the grind marks are pretty much
invisible.

The big advantage is that the fixture stays on the adapter I made and
the adapter mounts quickly in place of the tool rests using wind
nuts. So the fixture is not in the way, yet is easily put in place.

Dan

I start with the cutting edge and kind of "roll" the bit against the
wheel. I shade the bit tip with my hand and hold it up to the window
and rotate it to see that the grinding is equal on both sides. Both
corners should disappear at the same time on the same level. Then I
look down on the tip to see that the tip is centered and both sides are
the same.