6×48″ belt sander build

I want to try to make a belt
sander similar to this one, and I came up with
a design for one in 2012, but I never got around
to building it. and I went through some of my
junk, and decided to use this 14 millimeter shaft for the
main shaft, because I've bearings that fit on there,
and for the idler shaft, I figure I'd use this 3/8 shaft,
or about 10 millimeters. Now, the drive wheel on one of
these things, ideally would have rubber on it, and for that
I bought this inner tube, which will hopefully be usable. Well, it turns out the rubber on
the inside is a little bit thicker than the rest of the
inner tube, so that kinda sucks.

Here's a bicycle inner tube,
a really thick one, and I just cut a piece off the
end of that, and it looks like I can stretch that quite a bit,
so maybe I can use this inner tube.
The drive pulley's gonna be 8 centimeters in diameter
so I'm just making a whole bunch circles out of plywood
that size. I'm gonna glue all these
together on the shaft, and to keep them from spinning,
I want some kind of a keyway in there,
so first I'm gonna mark where this comes to. Now, I have to cut that cylinder
perfectly round, which I could do by sanding or lathing,
but instead, I'll spin it over my table saw,
just with a cordless drill. It's taking quite a bit of
tweaking, but the shape I actually want is for this to
have a bulge in the middle and that will help the belt
in the middle.

It had been my plan to just
stretch rubber over this, in longer sections like this,
but I found this is already too much to try
to stretch over this, so instead, I'm gonna try to
coat this with silicone. The weird thing is I didn't get
any silicone on my hands. I made the idler drum the same
way, except the disks are smaller, and the shaft
is also smaller.

I also have to slightly modify
my jig for rounding it, because the diameter is smaller,
and the shaft was shorter. Let's see if I can get those
pieces of inner tube on there. They still need
quite a bit of stretching. Yeah, it's doable. I'm not sure if those ridges
have much of an impact, but they're easy enough
to cut off with a knife. Now that I have the rollers made
I printed some one to one drawings from the SketchUP
model using my BigPrint program. Now, I don't have all the
dimensions on here, but all the ones that I didn't
label, I can just measure straight off the drawing. These bearings are 32 millimeter
outside diameter, which luckily makes for a tight
fit, in a 1 1/4 inch hole from this drill. So, the important thing is,
to still have a way to get the bearing back out.

So, here's how this
fits together, these two things form the sides,
and then in here, we have a cross-brace
that's here, and another one here,
and then we have this piece here,
and that's elevated a little bit Fits underneath this part here. And, this part fits on top
of here, and this is actually
a little bit further up, and then there's this funny part which gets pulled on here,
and pushes this part out that way, and then we have
the pieces here for mounting the bearings.
And, on top of all that, we have this part here,
and the backer for the belt goes on here,
and of course, the rollers are here and here.

Before putting in the ball
bearings, I drilled a couple of holes, which allow me
to push it back out, and I also drilled another
smaller hole in there to make sure the inside part
of the ball bearing won't be rubbing
against the wood. The roller is about 3
millimeters higher than this piece of wood, which is
about where I wanted it to be. This part goes on here,
and that needs to be square, and looking at it, I can tell
that it's not quite square.

I start by drilling pilot holes
for the screws, and then I drill a larger hole
for the shank, and after that,
I countersync then, and then I drive them in
with a drill. This cross-brace goes in
right about here, and I'm just gonna use the tips
of the screws to mark where I need the pilot holes.
I want to make sure I don't accidentally
drill the pilot holes through the plywood, but this
spacer is just perfect for that. Now, there's a slight screw-up
here, I have a gap of about a quarter
millimeter here, and it sticks out here,
so I'll have to trim that down a little bit on here,
and shim it on this side. When I need to trim off
just a tiny bit, I'll often just push it against
the stationary blade, and then when the blade spins,
it cuts off a tiny bit. Now, this part is gonna
go on here, but I'll touch that later.
and then this part goes on here, and this goes on top of here,
like so, and there should be enough
room in here for this to slide.

And, I've got that in here a bit
tight, so I have to add a shim here.
So, I decided that I do need this part on here to figure out
how the rest of it goes together but to not wear out
the screw threads too much, I'm using some screws that are
shorter and smaller than the final ones,
just to hold it together while I work things out. So, here's the shim I made for
here to compensate for the fact that this didn't have enough
room to slide in here. And, again I'm using smaller,
shorter screws, because this is not the final assembly. The idler roller
is gonna mount here, and I'll make some
wooden bearing blocks, and those will be attached to
these pieces of plywood. I just cut out some wooden
bearing blocks made out of Lignum Vitae, and I'm gonna
screw these in place before I drill
the hole through them.

The bearing blocks need to be
mounted to this part here, so that this roller is gonna be
about 3 millimeters above this surface.
When I first put this together, I found the bearings
very hard to turn, and so I put a 3/8 inch drill
in there and just, sort of, spun it around while tilting it
to the side but it got caught, so now I have
a huge hole right here but as it is, I'm just gonna
leave it like that. If those blocks wear out,
with this gash, I can always make new ones.
Not now. This thing is supposed to be
able to pivot a little bit to control the tracking,
but to keep it from moving side to side, like this, it's supposed to have this part
fit in between here, but this is a little bit
too wide right now and plus I also need to cut
that same profile into the thing
that's the top of the sander, so I'll just do that while it's
assembled on the bandsaw.

The way the belt tensioning
is supposed to work is I need something
to push this out here, and for that I've got this,
sort of, lever thing. And, for now, I'm just gonna
attach it with a screw. So, that pushes out her, like
this, as long as something pulls on here,
and for that there's a threaded rod with a knob on it
here and the nut that goes here and to keep that nut from
spinning, I made this block that the nut fits into. To control the tracking,
I need to control side to side here,
which is with a threaded rod through here, and I think I'm
just gonna put a couple of T-Nuts on here to push that
one way or the other. And, that turns out
to be a bad idea, because the problem is the
T-Nuts get stuck on these edges here
So, I made this funny shape block of wood, which holds
the T-Nut, and then that fits into the slot
together with the T-Nut, and it keeps it from spinning.

Well, I think I'm ready to
try this with a sanding belt. The shaft is 12 millimeters,
but this hole is 1/2 inch, and that makes for
way too much play, but making a shim
out of a pop bottle I can get that to be
a fairly snug fit. And, I also drilled a hole
for the set screw, so I should be able
to lock that on. There's still quite a bit of
work left to be done on this, including some sheet
metal to go underneath the belt here. I am pretty confidant now
that this belt sander will actually work, but that's
enough for this week now..

As found on YouTube

Related Posts