good afternoon youtube so i was uh using the 7 by 12 band saw here the other day so anyway i set the
saw down on the cut and it just started cutting there was a loud bang and then the blade
stopped moving the motor was still running and i initially thought the blade had just jumped off
the drive wheel or it had broken one of the two that's usually how they go so i flipped
it up and what i noticed was the drive wheel had a big crack right through the middle and even the
outer part right there it cracked and that's cast iron and this was like right before thanksgiving
anyway i kind of tossed around a couple ideas one thought was i could put this in a vise on the this
top end and i could squeeze it back together there seems to be a lot of stress in the park
the center pub there maybe had some tension because it blew outwards and i was thinking
i could try welding that up the cast iron but looking at it there seems to be a lot of porosity
inside the hub i put my endoscope camera down there and you can see pits all over inside there
i think this drive wheel was defective just a bad casting so then i set about trying to find
a replacement for that and you can see i actually did find one let me go into some detail on trying
to find a replacement for that which turned out to be hard but then easy it's kind of a
really interesting story on these what i found was these 7 by 12 band saws
all the brands i have the central machinery or harbor freight version there's the grizzly version
jet makes one there's a whole bunch of other versions of this saw different retailers
they're all the same saw inside what i found the tricky part was trying to find somebody that had
the part that i needed in stock in the us and could ship it in a reasonable amount of time
so that was the hard part of this repair the main problem is this particular model saw
was discontinued about 10 12 years ago it was superseded with a new version of the saw
and about all i can see is the new version of the saw just has a different paint
scheme and it's the same saw all the mechanical parts are the same that is the part for the new
saw and it's an identical match in fact it's even the same casting number as the old part
this is the old broken drive wheel as this casting code in there h a y that's the only thing i see
on this one that's on the back side and if we flip it over there's nothing on this side
let me show you the new one here basically the same thing and if you look right here
but that's one eight one two one four dash two and if i go to the old harbor freight 7 by 12 band saw
manual and look up the part this part is listed as code 2 3 1 on their diagram
and then you go to the table for two three one and that's the part number
one eight one two one four dash so this is the same casting yeah so this
is the part i ordered from grizzly that's their part number p0561231
now the two three one is the same code as the old seven by twelve band saw manual it's the same code
on the new one and i ordered it and i got this one eight one two one four dash two which is the
old part number from the old manual so yeah this is a identical part
okay youtube here we have the band saw pulled the old broken drive wheel off of there and i've got
the key six by six by 25 millimeter key and that's the old part and then there's the retaining ring
off of the old one and so i've applied a little bit of anti-seize there and also on
the two set screws you've got one set screw for the shaft there and then another one
for the key so let's see if we get that lined up here i think that's lined up there
yeah the old one was busted so it just plopped right off of there
maybe i need to actually file or sand that old one the old shaft off
try to polish this thing up a bit
okay yeah that's where it's it's a little bit rough there i think i think when the old wheel
let go the key way must have pulled out of the slot here and deformed it a little bit
yeah that would the key would have pulled out this direction and it's right on that
side let me spend a few minutes filing that down see if we can get it to fit
okay i think that did the trick i just did a little bit of filing on there and now
i can kind of rock that on and off and now it just taps on
nice and easy okay it looks like the blade is cutting pretty well
and one thing i notice is there's no vibration it looks like she's cutting pretty good i had to
adjust the tension a few times kept slipping off the drive wheel but i think i've got it
tightened up now and yeah the one thing i notice is i'm not getting the intermittent vibration
during cutting that i was you can hear the saw try to start to vibrate it'll make a little bit
more noise and then it damps out before it would get to where the whole saw frame was jumping and
you could actually see it moving this started a couple years ago maybe that crack was starting to
affect that maybe the wheel was getting a little loose and jiggling around and maybe that was
what was causing the vibration so maybe i fixed the vibration because i couldn't
figure out what the vibration was coming from because i'm using the variable pitch blade there
which is supposed to be anti-vibration the idea is it's 10 to 14 teeth per inch random across
the blade so you don't have any standing frequencies from the saw teeth yeah so far
looking like it's working well so i got a bunch more parts i got to cut here and get going because
we've been shut down for the better part of a week now since we couldn't cut anything so if you have
any questions about that post up in the comment section below and as always thanks for watching