i built this six by 48 inch belt sander five years ago and it's the belt sander i use the most
i've used up about five or six sanding belts with it and the question is how is it held up
using wooden bearings for the idler roller was a bit of an experiment
and uh i can't really see any signs of wear on those i figured they should be good for at least
another 10 years the inner tube covering on the idler roller has held up really well no issue
with that for the drive roller because it's bigger i couldn't quite stretch an inner tube over that
so i coated that with caulking and spread that nice and evenly and that has for the most part
held up except for this one spot there's a bit of a gash in it here and that's because i'm usually
using this thing as an edge belt sander and that gash is right at the level of the table where i'm
doing a lot of the sanding if i was building it now i'd probably buy a fat bike inner tube to put
over that bigger roller but back in 2006 those weren't very common so i hadn't thought of that
and i should have just put this on there a bit thinner and then this wouldn't have been an issue
mind you i hadn't actually noticed that there's a bit missing here until i actually open it up now
the belt started slipping on me one time so i moved that motor
over this way a bit to add more tension right now it's as far over as the mounting
bolts will go so if it starts to slip again i'll just have to replace the belt
i made the motor pulley out of wood part of the motivation was to cut 10 off the bill of material
which basically pays for the plants because that's what i charge for those
but the wooden pulley is not entirely optimal you can see there's some cracks in it here and here
and here and i think the reason that's got crocs in it is because it dried out too much just from
heat because when i use this sander for an extended period of time that gets fairly hot but
this pulley is made out of very hard wood and if it never breaks i might glue it back together with
construction adhesive because even heat doesn't seem to undo that i should have left a little bit
wider in this direction in that direction which would have given a bit more support
a problem with a wooden pulley is it's not very good at conducting away heat so if ever the
machine stalls in such a way that the motor still turns but the belt doesn't move you have a lot
of heat being generated here and the belt is not moving to carry that heat away and unlike aluminum
wood doesn't conduct that heat away very quickly so you end up with a smoking belt pretty quickly
this is much less of a problem for big wooden pulleys like i have on my bandsaw wheels because
if it ever stalls um it always slips on the smaller pulley that's the motor pulley not the big
wooden pulley the other pulley on here is a half inch pulley and it's on a 12 millimeter shaft that
didn't quite match up so i had to put the shim in there when i put it together and that's held up
really well better than i expected because the set screw pulleys often come loose because these cheap
aluminum pulleys usually have just a tiny little bit of play on the shaft as it turns the belt is
pulling it this way and that way and this way and that way basically constantly pulling that thing
back and forth and if it's at all loose it keeps wiggling and over time it makes that hole bigger
so imagine this is a set screw pulley on a shaft that is just a little bit smaller
so it can wiggle and if you clamp it down with a set screw like that it makes contact up here
and down here but not on the sides so the only thing that keeps it from wiggling side to side
is friction here and here so unless that set screw is really tight it just kind of wiggles
a little bit like that and then with friction it just wears things out a bit more and then it just
wiggles more and more and more and eventually the pulley becomes unusable i've seen on some pulleys
they have a second set screw to basically clamp it more into a corner but it's still not ideal
for a large industrial application it's typically more of a collet like it's used to hold a rotor
bit in a router and the collet is just a conical sleeve with a few slots in it so it can shrink
and expand a little bit that goes on the shaft and then the pulley would have a conical hole in
it that goes on top of that and that wedge is in there nice and good and then there'd be a flange
that is screwed against the pulley to push that collet on there to keep it on there nice and tight
and for some unattended industrial machine or hvac system that nobody's watching having that not come
loose is really important whereas in my workshop if a pulley starts rattling i notice and i fix it
certainly the pulley in my table saw has started to rattle from time to time and the pulley in my
20 inch band saw also rattled at some point and i just shimmed it and that fixed it and i found
if i take one of these pulleys and i put a plastic shim in there so tight that i have to hammer it on
that doesn't come loose over time and two other things i changed is i added these labels because
i was forever getting confused which one is which so this one is tension and this one if i turn it
this way moves the belt up and then also the wooden spring thing in the back this part here
was a bit too thin originally so i had to replace that with a thicker one but back to this sander
it's connected to a dust collector which is also connected to the switch that turns this one on
so it has its own dust collector it's the one back here i should check how much dust is in that one
it's been a year and a half since i last emptied out that dust collector
sanding dust is just very fine dust and generally cyclones don't do that well with it
but i find if i suck a whole lot of it out with a cyclone at once
then it ends up in the bucket and then it's easy to get rid of
these wood screws may wear out eventually if they do i'll use longer screws and
if those were out then i use bigger screws and if those were out i might
put plugs in there the dust level in the collection bucket went from down here to
up here so that was quite a bit of sanding dust i just sucked out of the filter and what's prompted
me to film this update video is i've been working on editing the five-year-old build
series for the sander down to one shorter video so i thought an update with that would be nice