I quite like this strip sander, although sometimes
when sanding intricate shapes, I often end up hitting
the back on here. I thought it'd be fun
to try to build a bigger one, and I found this belt
and it's 42 inches long versus 30 inches for the other one
and I thought I'd try to use some roller skate wheels
and I've experimented on the table saw
and I was able to cut this one flat.
My idea was that this would be just a quickie project
but then I thought I'd work out some of the details in CAD
and a day later, I came up with a complete CAD model
for the whole sander, for a lot of the rectangular parts
I won't bother going on the templates, but for the
parts in this corner they're complicated enough
I'll use them. I like to make best use of
odd shape scraps that I already have.
And, with templates like this it's easy.
This would be pretty much impossible with C&C.
I stuck these two pieces together with a bit of
glue stick just to make sure I get the alignment of this hole
and this slot exactly right with respect to each other.
I drilled this hole most of the way through so that only
the point went through. And, I'm using that hole
to line up where the Forstner bit goes from the other side.
I was originally planning on putting the bearing on
this side, but the belt is gonna go on this side,
so I figured if I put it in from the other side,
it won't get as much dust.
My plan is to put it together with glues and screws,
but for now it's screws only in case I need to change something.
It's really difficult to get these pieces aligned
and screw them together at the same time,
so I just marked the geometry of these holes on here,
and I'll drill those out and then use the holes
to line it up as I screw it on.
These two parts need to fit in here,
so I'm just gonna use two other pieces of plywood
and put those on here like that,
so I can get the alignment for the screw holes from here.
Well, these two bits need to come the same distance forward
this way, so if I clamp that to be flush here,
that'll give me alignment for this part here.
These two things form the upper wheel mount,
and there's a piece of plywood that needs to screw
on the back here. And, I need to get
the alignment just right so that the front pulley isn't
skewed in any way.
So, this is a scrap from cutting that piece there,
so I'm using this as a space, but because I don't
want it to be tight, I'm adding a couple layers of paper
in here. And, they need to come
exactly the same amount forward.
Checking again.
Having drilled two pilot holes, I put two screws in
to fix the alignment and then proceeded to drill the rest
of the pilot holes.
Having drilled all the pilot holes, I took it apart again,
and then expand the holes in the piece and screwing on,
so that the screw thread won't engage that
and the screws will really pull it together.
Now, I got to turn one of these wheels into something
more like this, except not quite like this,
because this one I cut a little too deep, and I cut away
all the rubber. So, I set-up this
circle-cutting jig,
to cut most of it away on the band saw.
Nice and flat now. Next I'll put a crown on it,
by cutting a bevel off either side.
So, there's my rubber wheel with a crown on it.
By roughing up the end of the shaft and this hole
is a little bit too small, so I figure if I hammer it in there
I should get a good hold.
So, here's the drive wheel, and I put a crown on it,
too, with a table saw blade.
It's a little bit rough but, that means it will have
more grip on the sandpaper.
So, I just filed a small key-wa in here, and another
key-way in the end of the shaft with an angle grinder.
So, now I can put those together/
And, now a small nail serves as a key.
Now, this is where things get a little bit unsafe,
because I'm gonna use the table saw to carve
a V-groove into here, and I'm gonna turn it with the drill
from far away, so that my fingers won't get into trouble.
Well, not looking too bad, but the groove is
much too rectangular.
Well, this pulley is less than perfect,
but it fits the belt,
so I'll stick with this one for now.
So, I use a different shaft to form this pulley because
this one's already got the belt pulley on it,
permanently, so now I just need to somehow
put that on here.
And, I want to move it back a bit further so I'm gonna
cut a key-way right here.
When I'm grinding that key-way I actually used a block of wood as
a guide for my angle grinder and I just let it rub against that.
Before I can mount that shaft, I need to fix what I have so far
on the base.
To get this shaft perpendicular I drew a line down here
and then putting this bearing holder on here
I just have to eyeball it so that this line is
parallel to the shaft, and then I can screw it down.
Well, I made some kind of miscalculation
because my belt is a little bit slack and I can't tighten
this any further.
So, what I'm gonna do is
take this piece, unscrew it, and move it up a little bit,
to take out that slack.
I need to get the lateral position of this pulley
just right, and for that I'm using a little
spacer washer. and one of these bushings that
actually came from the roller skate wheels, and that goes
right up against the bearing. Although, it probably won't
end up spinning. So, I'm just gonna put
a little bit of oil on here
so I won't get too much friction against it there.
And, on the other side, I'm using another one of these
little spacers And, then I made
this little block to go around the shaft
to lock it in place. And, now it's stalling
the pulley. And, for a key, I'm just gonna try to use
a screw, see if that goes in there nicely.
I also need to keep this wheel from sliding back and forth.
So, I made some spacers that fit very tightly on the shaft.
Now I need something to push the back of the top wheel mount
down to apply belt tension.
I'm using a 1/3rd horsepower furnace motor that
came from the garbage.
It works!
There's a tracking adjustment that goes down here,
which I haven't built yet, so I just jammed this
screw in here. But, this block
with just a screw in it right here,
is for adjusting what angle this shaft is gonna go at.
So, this carriage bolt, and this knob,
lock the table on. And, to keep
the head of the bolt from spinning,
there's this little block that goes on here.
I've been noticing a fair bit of bearing chatter from
these wheels, and it turns out the bearings actually
don't fit entirely tightly in here.
So, to make that for a tight fit,
I just made a paper shim,
and then the bearing.
I still to make an enclosure for it to keep the fingers out,
and the dust in.
I am adding some stubs to the frame so I can
screw on the cover.
While I had the sander apart, I also moved everything
this way a bit on the base to get more room on this side,
and added this hole here for pulling the dust out,
as well as wiring it up with a electrical switch
on the motor.
So, originally I had an Allen key that would adjust
the tracking screw, right here, but that was awkward
to adjust, and I want the dust collector hose
to come out this way,
So, here's my new tracking adjustment, it's basically
just this block of wood with a bump on it,
that pushes the shaft this way,
and it fits on top of this threaded rod
with a slot in the bottom.
And, then I put a knob on here
and that way I can very conveniently tweak
the tracking because I'd often want to tweak just
where the edge of the belt is, with respect to the platen,
because when I'm edging some inside corners,
that alignment is pretty critical.
I'm also making a belt guard, just so that the safety
controls will leave me alone.
So, now it's all done and I didn't film painting it
because that's boring. A strip sander like this
can be used to sand curves just like a spindle sander,
but how do you sand the inside curves?
And, this is where the coolest feature of the strip sander
comes in.
I should replace the platen on this one and this platen
is convex for rounding inside curves.
This machine can't get into inside holes
like you could with a spindle sander,
but at the same time it works a lot faster
and it can get into places that a spindle sander couldn't.
And, also the dust all gets sucked into the machine
so you don't have all this dust all over the place
like you would with a spindle sander.