These are part of the rough-cut pieces ready to be run
through the thickness sander. As you can
see there are some burned areas left by the bandsaw blade. In looking at the sawdust it also shows signs
of being a little burned. This has been
going on for a little while so I think it’s time to retire this blade and put
on a new one.
Ever wonder how to change a bandsaw blade? Well, here is the way I go about it. By the time I am done you will see why I use
the ½” blade almost all the time and don’t change to a different size
frequently.
The photo on the left is how I keep the bandsaw ready to
go. The photo on the right has the light
and magnetic fences stored on the bandsaw taken off and the doors open. If you are wondering what the parts are in
the bottom right, they are the old blade guides the saw originally came with.
Next is to remove tension from the blade. I typically do this after I get done with the
saw for the day but because it had just been in use the blade was
tensioned. The white round zero
clearance throat plate has also been taken out.
The guides near the top of the photo have been loosened and pulled back
from the blade along with a second set under the table. On the right circled in red is a tapered
bolt-pin that still needs to be removed.
Its purpose it to keep the cast iron table flat on both sides of the
slot. The slot is where the blade will
come out.
Cleaning the tool is next. I blow or vacuum all the dust off inside and
out. The old blade is removed, set aside
then the wheels are cleaned and the bearings checked along with the other
moving parts.
A bandsaw blade comes coiled up similar to this only in a
tighter coil. Unwinding the blade can be
fun. Nothing like playing with a 133”
long piece of coiled spring steel with 399 razor sharp points just ready to rip
you to shreds. Blades less than ½” wide
are not too bad to work with. This blade
at ½” wide is OK as long as your careful but I have a 1” wide blade that is
another story. When it’s time to uncoil
it, I have been known to go outside in the yard, throw it up in the air then
run away while it uncoils and tries to eat me.
Once uncoiled the blade in installed in the saw, tension
slowly added, the tracking checked and the adjustment of the guides can
begin. Here is what the adjusted guides
look like.
The first step is to set the guides on either side of the
blade just behind the gullet of the teeth.
With that done the top guide that’s behind the blade is set so there is
just a tiny gap between it and the blade.
The top photo shows that done.
Next is setting the tiny gap between the side wheels and the blade. You can use a sheet or two of paper but I
just eyeball it. When adjusted correctly
and the saw running the wheels do not spin until pressure is applied to the
blade and cutting begins.
As mentioned earlier there is a second set of guides
under the table that need to be adjusted just like the set I just did only with
a lot less room to work and it’s hard to see what you are doing.
Two things remain before I can call it done. A test cut is made, here a scrap of quarter
sawn white oak is used and the results speak for themselves. A nice even smooth burn free cut even at the
bottom where the cut was made through a knot.
The last thing is to coil up the old blade and set it aside for a backup
in case this one breaks or I need to cut some wood of questionable origin that
might have a surprise rock or nail buried inside.
Once all the pieces have been run through the thickness
sander, I go through deciding which piece to use for what and laying the blanks
out working around any flaws. Speaking
of flaws this is the piece of walnut that will be used to make the knobs. The problem areas that I need to stay away
from are circled in white. The clean
part at the top above the horizontal line is what I will cut off and use.
This is the final layout with each piece marked and labeled. There are some just noted as "test". They are for just that, testing machine
setups and joint fitting. They are also
big enough that I can make a replacement if an irreversible problem comes up or
something goes wrong and I have to start over on a part.
Cutting the dado joints in the top and bottom are
first. Here is how the top, bottom and
sides will go together.
There are a couple of ways I cut dados. Using a table saw with a stacked dado blade
is one way or using a router is the other.
For these a router will be used.
That’s because since the joints will be exposed, I want an absolutely
flat bottom and square corners. My dado
blade cuts a pretty flat bottom but because of the way some of the teeth are
ground their points leave a tiny little angled cut line where the side meets
the bottom. You can see the different
teeth in the left photo. A router on the
other hand cuts a flat bottom with a sharp square corner. The photo on the right has the left dado cut
with a router and the one on the right is cut with the table saw showing the
tiny little angled cut line. Both are ¼”
wide and deep.
Next Up – Routing Dados, Tenons, Machining Top &
Bottom
No comments:
Post a Comment