Tutorials Hints and Tips Page
6
Click on any of the thumbnails
below for a more detailed photo
Training Wheels for Knife
Grinding As I claw my way up the
learning scale of blade grinding, I'm finding out a lot of things. On my
first few blades, the horizontal grind was erratic and wavy and the depth
of grind was inconsistent and appeared sloppy . Although I've seen
some of the master's freehand this and was dumbfounded at their skill I
knew I had a long way to go. I decided that I needed "training
wheels".
To keep the horizontal grind consistent
as you draw the steel bar stock across the grinding wheel, a good table is necessary.
This is simply a good piece of plywood with some sheet aluminum on the top
mounted to a base made from 2" x 12" stock cut to fit snug against
the wheel. The table is held on by two drywall screws for easy removal while
changing belts.
To figure depth and height of
the grind line, I i used a sketch of the 10" grinding wheel and used
this to figure the angle necessary to make the grind line fall
where I needed it to. The closer to 90 degrees that you hold the blank,
the higher on the blade the grind line will be.
I transfer this angle to a
cut made on on a common 2 x 4
To make this "push
stick" easier to work with I cut an easy to use handle on the rear.
Doubt if I'll win a Nobel
prize for this, but this little invention has improved my technique and
saves me a lot of time and grief. Two pieces of sheet metal with two screws
serve as a stop that attaches to the blade to help determine here the grind
begins
The stop installed on a sheet
of flat stock steel to be ground. Picture shows how the stop bumps up against
edge of sander table to limit where the grind line begins. If you're doing a
symmetrical grind, make sure but left and right edges of the table are equally spaced from
the edge of the sanding belt.
Hold the steel stock tight against the push
block to maintain a constant angle. Hold the push stick still while holding
it tight to the grinding wheel. Draw the steel stock horizontally across the
grinding belt using the push stick to hold it tight to the belt.
Done: easy and straight grind
line. The red line on the enlarged photo will show you how I plan to grind
the tip at a geometric angle to make a slim tanto style.
Grinding Knife Blades
Edge Up; Training Wheels I have always thought
that knife blades should be ground edge down, but I have recently been
reading more about grinding blades edge up. If you think about it, this does
offer some advantages, not the least of which is being able to see the edge
and how close to the center line you're getting.
Here's the basic idea. the
base of the blade is held tight against a base block or screw while drawing
the blade steel horizontally across the grinding wheel. As the blade is
ground, the edge will rotate into the grinding wheel. Grind this to the
center line.
Since the blade is tapered
and I want to keep the edge absolutely horizontal in relation to the
grinding wheel, I use a level to figure out how much I'll need to raise each
side with a spacer to rest the blade on. It turned out to be less than
1/8"
I clamped a scrap piece of
metal to the left side to act as a rest to guide the tapered blade over. I
also drove a screw into the bottom of the jig to rest the base of the knife
against while drawing it horizontally across the grinding wheel.
Reverse the setup by moving
the scrap steel rest to the right side of the jig and grind the other
side of the blade. Notice that I use a magic market mark to show me where to
start the grind.
And this is what I ended up
with. I did a final few passes with a fine grit belt and did final shaping
of the handle on the knife belt grinder . Notice how I engraved
my name and type of steel ( A2) on the blade before sending it out for heat
treatment.
Closing note: grinding blades is an art that
takes a lot of practice to get good at . I still ruin about one out of three
blades I try to make. I hope that the above techniques help shorten your
learning curve, but truth be known, the only way to get good at this is to
practice, practice, practice.