After participating in a
recent thread about scratch stocks on the old tools list, I decided
to make one. In the process, I learned a couple of things I want to
First take a look at the
finished stock. It is from a piece of Brazilian rosewood I have been
saving for a long time, mostly sapwood. It is about 1” thick by 4”
1 ¾” wide. The size doesn’t matter. It needs a wing
screw to hold the blade in place. I used a ¼-20 screw.
It is sitting on my first
piece of work using the stock. You can see the beads on either
side of the board.
Next is a picture of the
blade I made. I used this picture so you can see the pattern I
ground into the blade. The pattern means nothing, I just
needed to grind something so I could make this tutorial.
Next is a picture
of the entire blade with the pattern cut on both ends. The pattern
or patterns you choose are a matter of personal choice.
I made the blade from a
piece of steel I cut from an old 2 man crosscut saw. I have
been cutting stock off of this old tool for years now. I use a
die grinder with a metal cutoff wheel to cut the saw steel.
This piece is 1 ½”wide by
6” long by .060” thick. The thickness of the stock helps to prevent
chattering. I can cut this long piece into 2 pieces when I want more
patterns. I could have bought some 1/16” 0-1 steel for this
and avoided the grinding, but the 0-1 would have been soft, while
this saw stock is moderately hard.
As you can see, the steel
is pitted, and that pitting would interfere with making a good sharp
cutting edge. I used a disc sander in various grits down to
400 to get below those pits along the edges, far enough back so it
will not impinge on the cutting edges. After I had it ground,
I used my hard felt wheel to polish it. Then when I ground the
profile it was really sharp.
Next is a picture of the
end showing the tapped hole, and a piece of 3/16” brass round stock.
I have never understood why, but the loose piece of brass in the
hole makes for a tighter grip when you tighten the screw. This
is probably because the brass is flat on the end and makes good
contact with the blade. I am not sure. I use this little trick
on a lot of set screws.
Finally, here is a picture
of the side of the tool. I simply sawed a groove wide enough for the
blade to slide into.
This is a really simple project, and the only things new here are
making the blade from an old saw, and adding the short piece of
brass round in the hole. I have been wanting to have a tool to
make beads along the edges, and now I have one, thanks to the guys
on the old tools list. I am sure I will find more uses for
this little tool.
It sure works great!
Jim D. Thompson