Living Jackson

Benefits of cycling
New Wheels for the Homemade Bandsaw

New Wheels for the Homemade Bandsaw

This video is a little bit longer, but also
very detailed. I first talk a little bit about the saw itself
and explain why I wanted to make new wheels for it.
If you only want to see how I make the wheels, just click the annotation in the video. This is my homemade bandsaw, that I built about one year ago with the plans from Matthias
Wandel (link in the description) And as you just could see it performs really
well. But when I built it I changed several things
in the design, so it would fit my needs. The first change I made was the size of the
cart, that goes under the bandsaw. It is a little bit wider in this direction, because
I originally used this very heavy motor and it had to be supported with a bigger cart
so the saw won’t tip over because of the weight of the motor.
But a while ago i upgraded the saw with this motor, which I got for free. It’s also a 2hp
motor and it runs at 1400rpm. So now with this motor i got the blade speed that I like
and that’s about 21 m/s. The only challenge with this motor was mounting it, because it
didn’t had a foot, but just this mounting flange.
So I made a new belt cover and this piece is now really thick and the motor is bolted
into it. But because the motor has such a high starting torque, it always wants to rotate
this way when I fire it up. And to prevent that I jammed a block in here, so the motor
will stay in place. And the belt always slips a little bit when I turn it on.
With this motor I now have a blade speed of about 21 m/s, which is really fast. But now
that I worked a little bit with it I really like that blade speed and the motor is powerful
enough for that blade speed to work properly. But the high blade speed also brought some
problems with it. So because the wheels now spin much faster, I got a lot more vibration
on the saw and I had to lighten the wheels so I cut big holes into it and also re-balanced
them better. And now they can handle this high rpm and the saw doesn’t start to vibrate.
The other problem was, that a higher rpm also meant more centrifugal force. And this the
14″ inner tube that I originally used on this saw. But it couldn’t hold up with the high
rpm. The centrifugal force pushed it outwards and it slipped off the wheel, so I had to
put on 12″ inner tubes on this 16″ wheel. But the major problem is the sawdust, that
flies around here and because of centrifugal force gets caught in the wheel and that’s
kind of a problem with this wheel design. You can see that here is a little layer of
dust at the side of the wheel, which is not actually a problem. But at some point I got
the sawdust under the tracking part of the wheel and this made it uneven and really rough
to the blade. Actually when I cut up the walnut bowl blanks there was so much dust between
the wheel and the tire, that it started to come of while saw was running and there was
a blade on here and this was kind of scary. So I thought a little bit about it and finally
decided to make new wheels with a slightly different design then the original ones. And
that’s not to bad, because I wanted to change the bearings anyways someday and now that
seems for a good opportunity, because they sometimes start to make a really annoying
rattling noise. {rattling}
So let’s make them! So here are some of the bearings I used for
this saw. I used them because I got them for free and three of them were in good shape
and one of them was in reasonably good shape, but this one is what I think makes the rattling
noise. So I ordered some new bearings to replace the old ones.
I wanted to make the wheel-body out of MDF this time, because it is really flat and consistent
and should be easy to balance, which was my main concern on this build.
I bought 16mm MDF and in order to get the right thickness I have to glue two pieces
together. So I took a little bit of glue and spread
it over the entire surface. The band-clamp is there to just keep the two pieces aligned
when I clamp them, so nothing can slide around. Then clamping with 4 spring-clamps …and some more spring-clamps …and a lot of other clamps. I also tried to get some clamping
pressure in the middle of the sandwich with two blocks and two rails that are clamped
together. While I’m waiting for the glue to dry, I can start on making the new bearing
flanges. They have to be really strong and need to be made out of birch-plywood. I had
a scrap piece and luckily it had the same thickness as the bearings. I simply cut 4
squares out of it. Then I marked the middle of all of them. Next I need to cut a hole
in the middle to press fit the bearing into the flange. The bearing has an outer diameter
of 52mm and I have a Forstner-bit that cut a 50mm hole. That’s too small. I have a good
hole-saw that cut 51mm holes. It would work, but the fit is then so incredibly tight and
it would be really hard to get the bearing in. But I also have a cheap hole-saw, that
says it cut 51mm holes, but it cut a little bit bigger and that’s good for press fitting
this bearing. So sometimes the cheaper tools are the better ones. To prevent tear-out, I drilled from both sides. Next I hammered the bearing in just a little
bit with the help of a piece that has a hole in it to prevent the bearing from damage of
the hammering. The rest of the work is done at the vice. After that I trimmed all of them
to their final size. And rounded and sanded the corners. Now the glue of the wheel blanks
is dry and as I don’t have a compass big enough I used a scrap piece with two holes in it
instead. Then I marked the layout for the holes that I need to cut into them. I drilled
a little hole in the center and used two of my small storage boxes, which guide the drill-bit.
This hole is then used as the pivoting point to cut out the circle shape. It was at this
when I noticed that it would have been better to first cut out circles and then glue them
together, but it didn’t matter really much. I had to drill the hole in the middle by hand
because my drill-press can’t reach there. But it doesn’t need to be super accurate,
just big enough for the shaft to fit through. The big holes I then cut with a hole-saw on
the drill-press. I made more and bigger holes than the plans call for to lighten the wheels.
This took a lot of time, because the MDF really gums the hole-saw and I had to clean the teeth
several times. But it worked ok, I didn’t get too much burn marks. But the holes cut
with the Forstner-bit went really easy and also produced a lot of chips. Then I sanded over all the burn marks left by the hole-saw. Now I’m ready to glue on the first flange
on both wheels. It should be as centered as possible and in order to do that I made this
little helper. I just turned it on the lathe. It fits in the center hole of the wheel and
the flange fits on top. And now it’s centered. I spread the glue just on the outside, so
when I clamp the flange, the glue won’t squeeze into the bearing. While the glue drys, I can
start to take apart the saw to get access to the wheel shafts. I case you wonder about
the wood pulley on the motor. It is still in really good shape. Here are the old wheels
and the shafts and as you can see the bearings were quite rough on these shafts. So let’s
see if the new bearings still on this shaft. “Yes” I still wanted to get rid of some burr
and rust, so I chucked them in the lathe and ‘ground’ it away. And some sanding with 600
grit paper. Now with the glue dry on the first flange I can carefully slide it onto the shaft.
And now I can put on the second flange. And it has to be glued on exactly straight, so
there isn’t any kind of side wobble in the wheel. The flange is now just clamped on and
I can check the wobble with this piece by looking at the gap. And right now there definitely
is some wobble. I tried to correct the wobble by changing the position of the flange with
some small taps. I look for the part of the wheel that’s closest to my reference piece
and tap at the opposite side on the flange. Now the wobble looks something like this…much
better. Then the same procedure with glue. But this time I only had about 30 seconds
to get it right until the glue started to set. Well now the glue set and I can’t change
anything. I’m not super happy, but it’s very close. Yeah the second wheel came out better. I already could hear how much quieter the new bearings are. {silence} I put on the temporary
pulley just with clamps so that way it was easier to adjust it so it runs true and I
also don’t have ugly screw holes in the wheel. So here I set up for turning the wheel. And
now comes the part where I want to change the design. So I don’t want to turn just a
crown onto the wheel, but a full channel with a crown in it. Turning this MDF really makes
a lot of awful dust, so I setup two dust collection hoses and also wore a dust-mask. I first turned it round and then created the channel. So now let’s check the size of the
wheel. The plans call for 40cm diameter wheels or a circumference of 125,6cm and as you can
see I made it a little bit smaller, but I did this on purpose, because the varnish I
will out on there and the tire then will also have a little bit of thickness and with these
the wheel will then have the right diameter. I also looked that the crown is exactly at
the glue line, because the glue line is really really hard and it should hold up the tension
of the blades better then just the MDF. And hopefully with this design the sawdust that’s
on the side of the wheel just can’t get under the tire and flies away. Then doing the same
thing again with the other wheel. Now before I can go on with putting on the inner tube
and balancing the wheels I have to varnish them, because this MDF really needs to be
protected from moisture. The varnish is a high quality solvent- or oil-based PU. I got it from a painting store and it was a lot more expensive the stuff from the hardware store I used before. But when I look at the result… I never want to use something else
again. So here are the wheels now with two coats…. and I have to say they look amazing. Next I have to put on these inner tubes as the wheel tires. But just look at that. That’s
the old lower wheel and this is the amount of sawdust that was in between the wheel and
the tire. And that’s the sawdust from just two weeks, because I had to clean the wheel
after I resawed the slabs for my wooden bucket. I needed to cut them thinner. But this was
really easy, because I could follow some ridges. Now I simply have to get this 12″ tire around the 16″ wheel. I thought you now can see me failing several times. But because I cut the
inner tubes thinner, they stretched a lot better and was pretty simple to get them on. Next I need to attach the drive pulley, centered on the wheel. So I first clamped it, looked how true it run, made adjustments and screwed it on. 4 drywall screws will drive this bandsaw.
Now with everything attached I next need to balance the wheels. The plans call for using
some really easily running ball bearings and putting them on a screw driver and then putting
the wheel onto the bearings. But unfortunately my small bearings don’t fit inside the big
bearings. Now my solutions to this is. I made some housings for these small bearings and
this pin fits into the big bearing and then I can put a shaft through it and balance the
wheels on it. I used threaded rod as a shaft. I just let the wheel spin and settle at the
heavy point. And now I know that I have to remove some material from here. Then repeating this process until it’s perfectly balanced. One thing for sure: It’s much easier to balance
a MDF wheel than a plywood wheel. You see how much material I had to remove here to
get it balanced and here just 4 holes. Spray lacquer seals the exposed MDF again. Then
I could install the wheels back on the saw and make a really important test to see if
the tire stays on the wheel. Looks good. I made wooden washers, which help to secure
the wheels on the shaft. Then assemble more, install a blade and fire it up. So check this
out. It runs really quiet. Seeing that it works I could put on the rest. The saw is complete again, so now let’s check the vibration with the “balance a coin test”. I would call
this ” Good enough” While I was working on the saw anyways I took that opportunity and
installed a wheel brush for the lower wheel and it will just keep the tire clean from
sawdust. And without one there will develop a thin layer of fine dust over time and Matthias
Wandel himself mentioned this as a feature, but I don’t think that’s a 100% right. This
thin sawdust layer will protect the tire a little bit when you only cut up plywood or
dry wood. But when you cut up green wood. Some small logs or bowl blanks, then the sawdust
will really stick to the tire and gums up the inside of the blade and that’s not really
good for the blade. So I don’t know how well it will work. But it definitely can’t hurt. And now making some test cuts. And as you can see the dust just can’t get under the tire anymore. That’s exactly what I wanted to reach. And I think the cut result speaks
for itself.

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