Conchita, I will have to go in a few minutes for my dinner,
but I will complete today's by the end of today and make sure
I will uploard it.
What is seen below is a set of chopstics cases from
yesterday's work. Only one of them is good enough for
sale. Actually, the one on the left is the one which is
satisfactory for sale.
Here below, I am attemtping to make smaller versions.
Here below, some more larger versions in the making. These,
plus two sets of chopstics are the end products of today,
apart from usual coating, not shown here.
Today, I will talk a lot about how these pieces are actually
made, and difficulties I am facing, and possible solutions.
Below, I will show you the photos of the machines I need
for making these chopstics cases and will comment on future
operational procedures and how these came about, just today.
Shown below is a typical bandsaw. Set here is a piece of wood
for the case. Can you see that the orientation of the work
piece is almost vetical? That is, seen from your viewing angle.
What I am trying to do here is to cut out a slice of wood
that is not wanted. I am trying to cut along a straight line
from above to below. That may sound simple, but that is
not that easy, as I will be telling you after the dinner.
Here below, a schematic with two components of the
bandsawing in action, all seen from above. A short black
line is the blade, wanting to do in the direction
indicated by a red arrow. Note that these directions are
tangential to the local curvatures. The two big arrows in black
are the directions you might expect your work piece
may best move along. It is not so, no that easy and
simple. Blue arrows are the actual directions in which
you push your work pice. Here is the problem.
If, as in A, your push ditection is at an angle to
the blade direction then the blade will move along
the red arrow. That means you are no longer
cutting aling the straight line you wanted.
On the other hand, if you swing your piece around
so that your push direction is parallell to the
blade direction your intended cut line is maintained.
That is to say, you are cutting along the straight line
you wanted. In reality, you need a series of very subtle
piece swinging.
With dexterity and with this theoretical understanding
you can do just that!
Now, take a look at the milling machine. The idea here is that you
want to make grooves so that the walls on either side
of the groove are equally thin (or thick).
That again, is not simple at all. Up until this afternoon,
the only method I used was to look at the work piece and the
rounded head of the cutting piece in perspective.
However, if you move your hear sideways by even 1 cm,
that will lead to a staggering amount of paralax. Misguided,
and being unaware of this huge paralax you end up with
having one wall too thick and the other wall two thin!
The schematics below are meant to show you how you might
avoid this problem. I discovered it by chance today.
With metals mechanical properties are all isotropic, that is,
you do not need to choose certaindirections in which you
must proceed in making, say, grooves.
With wood, you have grains and you must follow a set of
rules, into which I will not go now. One outcome of
this is that the cutting bit, normally, must traverse
the work piece three times down the length. At the end of
the 3rd run you find that the cutting bit is at the other
end of the starting position. Since it takes a lot of time
to get the bit back to where it started the cutting process
you naturally wish to start the next groove making
process where the cutting bit is currently located.
That means, repositioning of the bit with respect to
the piece width.
The schematics above are shwong you how best you might do
the cutting bit positioning. First you make a small hole
and see how much off-set there is from the two walls.
If you find an off-set, the you correct for it, and then
make another slightly larger hole (or dip) and see if
you have made an improvement.
You then proceed for real groove cutting. With this method
my groove making has made a remarkable improvement.
The last schemetics are about the possibility of making doublets
of the holes you wanted. Normally, you want single holes at
either end of the work piece.
However, your soft iron pegs will not exactly slot
easily into the magnetic counter-holes. you may enlarge
the hole diametre by making extra shallow holes over and above
the existing magnetic holes. Unless you make a policy decision
about how you want these extra space around the magnetic holes
you may end up with doublets as shown in the schematic.
Doublets are ugly and my decision is to go for concentric
larger diam. overlaying holes. Not shown here. Either way,
these extra spaces are meant for easy seperation of the
case lids.
You might have thought that making grooves is easy...
It is not! You need a lot of thinking!
but I will complete today's by the end of today and make sure
I will uploard it.
What is seen below is a set of chopstics cases from
yesterday's work. Only one of them is good enough for
sale. Actually, the one on the left is the one which is
satisfactory for sale.
Here below, I am attemtping to make smaller versions.
Here below, some more larger versions in the making. These,
plus two sets of chopstics are the end products of today,
apart from usual coating, not shown here.
Today, I will talk a lot about how these pieces are actually
made, and difficulties I am facing, and possible solutions.
Below, I will show you the photos of the machines I need
for making these chopstics cases and will comment on future
operational procedures and how these came about, just today.
Shown below is a typical bandsaw. Set here is a piece of wood
for the case. Can you see that the orientation of the work
piece is almost vetical? That is, seen from your viewing angle.
What I am trying to do here is to cut out a slice of wood
that is not wanted. I am trying to cut along a straight line
from above to below. That may sound simple, but that is
not that easy, as I will be telling you after the dinner.
Here below, a schematic with two components of the
bandsawing in action, all seen from above. A short black
line is the blade, wanting to do in the direction
indicated by a red arrow. Note that these directions are
tangential to the local curvatures. The two big arrows in black
are the directions you might expect your work piece
may best move along. It is not so, no that easy and
simple. Blue arrows are the actual directions in which
you push your work pice. Here is the problem.
If, as in A, your push ditection is at an angle to
the blade direction then the blade will move along
the red arrow. That means you are no longer
cutting aling the straight line you wanted.
On the other hand, if you swing your piece around
so that your push direction is parallell to the
blade direction your intended cut line is maintained.
That is to say, you are cutting along the straight line
you wanted. In reality, you need a series of very subtle
piece swinging.
With dexterity and with this theoretical understanding
you can do just that!
Now, take a look at the milling machine. The idea here is that you
want to make grooves so that the walls on either side
of the groove are equally thin (or thick).
That again, is not simple at all. Up until this afternoon,
the only method I used was to look at the work piece and the
rounded head of the cutting piece in perspective.
However, if you move your hear sideways by even 1 cm,
that will lead to a staggering amount of paralax. Misguided,
and being unaware of this huge paralax you end up with
having one wall too thick and the other wall two thin!
The schematics below are meant to show you how you might
avoid this problem. I discovered it by chance today.
With metals mechanical properties are all isotropic, that is,
you do not need to choose certaindirections in which you
must proceed in making, say, grooves.
With wood, you have grains and you must follow a set of
rules, into which I will not go now. One outcome of
this is that the cutting bit, normally, must traverse
the work piece three times down the length. At the end of
the 3rd run you find that the cutting bit is at the other
end of the starting position. Since it takes a lot of time
to get the bit back to where it started the cutting process
you naturally wish to start the next groove making
process where the cutting bit is currently located.
That means, repositioning of the bit with respect to
the piece width.
The schematics above are shwong you how best you might do
the cutting bit positioning. First you make a small hole
and see how much off-set there is from the two walls.
If you find an off-set, the you correct for it, and then
make another slightly larger hole (or dip) and see if
you have made an improvement.
You then proceed for real groove cutting. With this method
my groove making has made a remarkable improvement.
The last schemetics are about the possibility of making doublets
of the holes you wanted. Normally, you want single holes at
either end of the work piece.
However, your soft iron pegs will not exactly slot
easily into the magnetic counter-holes. you may enlarge
the hole diametre by making extra shallow holes over and above
the existing magnetic holes. Unless you make a policy decision
about how you want these extra space around the magnetic holes
you may end up with doublets as shown in the schematic.
Doublets are ugly and my decision is to go for concentric
larger diam. overlaying holes. Not shown here. Either way,
these extra spaces are meant for easy seperation of the
case lids.
You might have thought that making grooves is easy...
It is not! You need a lot of thinking!
