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The other day I was cutting some stock with my HF bandsaw when I noticed a new scraping sound coming from the area of the bottom (drive) wheel.? Further examination showed that the blade was riding far enough out that it was scraping the inside of the blade cover.? Thinking that I just needed to adjust the tracking (something I haven't done since buying the saw), I started in on that -- but quickly discovered that the blade was riding properly on the upper wheel.? Not quite touching the flange.
Some additional experimentation showed that the drive wheel tracking problem is eased when I reduce the blade tension a bit.? I don't think I'm overtightening the blade and bending the frame -- I'd think the upper wheel would be more affected (but I could be wrong about that).
I'm not hearing any noise from the drive shaft bearings so think it's unlikely they have worn enough to cause these symptoms.? Maybe I just noticed something that is common to these lightweight machines?? On the other hand, if the problem is flexing in the drive shaft, that could be a recipe for metal fatigue and eventual failure.
Comments?? Has anyone else observed this?
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??? ??? I would pull the blade & check each wheel for
deflection both in & out & side to side . Have you ever
checked the oil level in your gear box ? I checked mine he day I
brought it home used . I could see that it was one of the newer
saws with very little wear visible till I got the blade cover off
& the gear box cover off . I bought mine with a bad motor ,
but I got it real cheap . I could see where the blade had been
scraping the inside cover at both the top & bottom . That was
the easy fix , I think I replaced one bearing & adjusted . But
before I could adjust the wheels I had to address the gearbox
issue . Mine was bone dry . There were 3 seals on one of the
shafts all of which were installed wrong , I replaced 2 seals
& maybe a bearing . Fortunately I caught mine before it had
caused a lot of damage to the brass gear inside the gear box . The
dry gear box on these saws is more common then you would think .
Make sure your wheels are both turning true & flat . I see
that the parts list for these saws?? ( the ones they currently
sell ) shows 2 seals but I could only find one in the parts list .
I was able to get the #'s off the bad ones & went to my
bearing house & got some good quality seals . I think there's
only 2 different bearings in these saws , I went on Amazon &
got a ten pack of each for @ $20 .
animal
On 2/15/2022 9:00 AM, Mark Kimball
wrote:
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Show quoted text
The other day I was cutting some stock with my HF bandsaw when I
noticed a new scraping sound coming from the area of the bottom
(drive) wheel.? Further examination showed that the blade was
riding far enough out that it was scraping the inside of the blade
cover.? Thinking that I just needed to adjust the tracking
(something I haven't done since buying the saw), I started in on
that -- but quickly discovered that the blade was riding properly
on the upper wheel.? Not quite touching the flange.
Some additional experimentation showed that the drive wheel
tracking problem is eased when I reduce the blade tension a bit.?
I don't think I'm overtightening the blade and bending the frame
-- I'd think the upper wheel would be more affected (but I could
be wrong about that).
I'm not hearing any noise from the drive shaft bearings so think
it's unlikely they have worn enough to cause these symptoms.?
Maybe I just noticed something that is common to these lightweight
machines?? On the other hand, if the problem is flexing in the
drive shaft, that could be a recipe for metal fatigue and eventual
failure.
Comments?? Has anyone else observed this?
|
Hi Mark Mike has it right.? I'd say that its 99.9% certain that the outer gearbox output bearing has failed. This is alway the first to go because the loads on it are highest due to the blade tension plus cutting forces and because load is cantilevered ~1/2" outboard of this bearing When it fails the internal clearances increase and this allows?the shaft to deflect, bending?upwards which tilts the bottom bandwheel and the blade tracks further out on the wheel, or even derails if the bearing failure is bad enough. Decreasing the blade tension (as you did) decreases the flexing of the bottom wheel shaft so it will? track more normally. This is all a?consequence of bearing failure alone. This bearing?fails almost always due to lack of lubrication. When you take it out you'll probably find its rusty! It's also why the gearbox inner bearing almost never fail?because they run inn the gearbox oil (unless there was?sand left in the gearbox - not unknown around 2007! - or the brass gear turned to slivers and damages them) It can stand the higher loading while adequately lubricated, but the factories always seem to use -Z (single metal?sheild) versions of the bearing size they choose, rather than -RS versions which have rubber seals. The rubber seals cause quite a bit of drag and are not meant to seal against egress of oil, just grease. Here's where I'd disagree with Mike.? Skateboard bearings (10 for $20) are the dregs of the bearing world, yes they're better than a failed bearing but replacing?them again is not something you'll want to do - it's quite involved to?get it right. I'd recommend you buy name brand bearings (Fafnir, NTN, etc? Even if you've never heard of the?brand - if they've put their name on the box, they'll be better than a sleeve of no-name bearings.? ?Although these bearings are 10x as expensive, the few actual?$ more it costs to do the?job is just insurance against having to do it again (and really what are you going to?do with the?other?8!).? I buy -2RS bearings and flick out the seals from?all but the outside seal on the outer bearings with a seal pick - you want the oil to circulate through the inner bearings. Technically you can get bearings without seals and ones with a single rubber seal but in reality they only supply without seals or -2RS bearings that have seals on both sides, eg 6202-2RS. The price difference between them?is negligible.?? There?is supposed to be only 1 lip seal between the inner and outer bearings on each shaft that is there to seal the oil into the gearbox and must be there even if you use?-2RS bearings. I pack the space between the seal and the outer bearing (inside seal removed!) with Moly-grease to give it a better chance second time round rather than rely on just? the factory grease load. You'll need to push the bearings out and back in again.? Although you can drive the output shaft?+ bearings and brass gear out (as a unit)? with a hammer and drift you cannot replace them that way - the bearings are a press fit in both the housing and on the shaft.? This is not good engineering practice but the load on the outer bearing is high and the separation between the 2 bearings is low, so the press fit is necessary.? A puller/pusher can be made from all-thread?rod and 1 1/2" SHS tube which, along with few tube spacers and washers, allows you to replace the bearings without removing the head from the base - i.e. you don't need an hydraulic?press. - jv
The other day I was cutting some stock with my HF bandsaw when I noticed a new scraping sound coming from the area of the bottom (drive) wheel.? Further examination showed that the blade was riding far enough out that it was scraping the inside of the blade cover.? Thinking that I just needed to adjust the tracking (something I haven't done since buying the saw), I started in on that -- but quickly discovered that the blade was riding properly on the upper wheel.? Not quite touching the flange.
Some additional experimentation showed that the drive wheel tracking problem is eased when I reduce the blade tension a bit.? I don't think I'm overtightening the blade and bending the frame -- I'd think the upper wheel would be more affected (but I could be wrong about that).
I'm not hearing any noise from the drive shaft bearings so think it's unlikely they have worn enough to cause these symptoms.? Maybe I just noticed something that is common to these lightweight machines?? On the other hand, if the problem is flexing in the drive shaft, that could be a recipe for metal fatigue and eventual failure.
Comments?? Has anyone else observed this?
|
??? ??? John I mentioned the Amazon bearings because when ever
someone ask about bearings folks respond with a Fafner , NTN ,
Timkin & then the person needing the bearings go's online
& see's what the price is for a real bearing & gripes how
expensive the bearings are but respond with I found these &
their the same part # . 8 out of 10 times they will pick the
generics ones on Amazon.
There's 4 of the 6002zZ bearings on that saw? A quick google for
the good brands? brings up prices from @ $8.75 to $16.37? each
Amazon come's in @ a 4 pack for $ 6.16 for 4 up to @ $12.00 to $
19.00 for 10 . Most folks will see , wow I can get 10 for the
price of just 1 from this guy? & that's what they do . I went
with the cheapies cause I could get them in 4-5 days to my porch?
& all the bearing houses had to order ..? This saw is my
second? one , I gave my first one to a good bud & the
difference in quality between the two is day & night . I do
have several NTN now that I got from a bud that were spares for a
piece of equipment he doesn't have any more so I do have good ones
for when the cheapies fail but right now seems like I may use the
saw once a month? ( life has gotten in the way ) I notice on the
parts list for this saw on HF's website they only show their part
# for the guide bearings not the 6XXX Z bearings that are used .
& to top things off here's the list of replacement parts &
about the only part that is not a off the shelf item in a lot of
places is the worm gear & the pivot . Pretty impressive for a
saw with over 200 parts .
But what the hell, these are almost expendable saws.
YMMV
animal
On 2/15/2022 1:09 PM, John Vreede
wrote:
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Show quoted text
Hi Mark
Mike has it
right.? I'd say that its 99.9% certain that the outer gearbox
output bearing has failed.
This is alway
the first to go because the loads on it are highest due to the
blade tension plus cutting forces and because load is
cantilevered ~1/2" outboard of this bearing
When it fails
the internal clearances increase and this allows?the shaft to
deflect, bending?upwards which tilts the bottom bandwheel and
the blade tracks further out on the wheel, or even derails if
the bearing failure is bad enough. Decreasing the blade
tension (as you did) decreases the flexing of the bottom wheel
shaft so it will? track more normally. This is all
a?consequence of bearing failure alone.
This
bearing?fails almost always due to lack of lubrication. When
you take it out you'll probably find its rusty! It's also why
the gearbox inner bearing almost never fail?because they run
inn the gearbox oil (unless there was?sand left in the gearbox
- not unknown around 2007! - or the brass gear turned to
slivers and damages them)
It can stand
the higher loading while adequately lubricated, but the
factories always seem to use -Z (single metal?sheild) versions
of the bearing size they choose, rather than -RS versions
which have rubber seals.
The rubber
seals cause quite a bit of drag and are not meant to seal
against egress of oil, just grease.
Here's where
I'd disagree with Mike.? Skateboard bearings (10 for $20) are
the dregs of the bearing world, yes they're better than a
failed bearing but replacing?them again is not something
you'll want to do - it's quite involved to?get it right. I'd
recommend you buy name brand bearings (Fafnir, NTN, etc? Even
if you've never heard of the?brand - if they've put their name
on the box, they'll be better than a sleeve of no-name
bearings.? ?Although these bearings are 10x as expensive, the
few actual?$ more it costs to do the?job is just insurance
against having to do it again (and really what are you going
to?do with the?other?8!).?
I buy -2RS
bearings and flick out the seals from?all but the outside seal
on the outer bearings with a seal pick - you want the oil to
circulate through the inner bearings. Technically you can get
bearings without seals and ones with a single rubber seal but
in reality they only supply without seals or -2RS bearings
that have seals on both sides, eg 6202-2RS. The price
difference between them?is negligible.??
There?is
supposed to be only 1 lip seal between the inner and outer
bearings on each shaft that is there to seal the oil into the
gearbox and must be there even if you use?-2RS bearings.
I pack the
space between the seal and the outer bearing (inside seal
removed!) with Moly-grease to give it a better chance second
time round rather than rely on just? the factory grease load.
You'll need to
push the bearings out and back in again.? Although you can
drive the output shaft?+ bearings and brass gear out (as a
unit)? with a hammer and drift you cannot replace
them that way - the bearings are a press fit in both the
housing and on the shaft.? This is not good engineering
practice but the load on the outer bearing is high and the
separation between the 2 bearings is low, so the press fit is
necessary.? A puller/pusher can be made from all-thread?rod
and 1 1/2" SHS tube which, along with few tube spacers and
washers, allows you to replace the bearings without removing
the head from the base - i.e. you don't need an
hydraulic?press. - jv
The
other day I was cutting some stock with my HF bandsaw when I
noticed a new scraping sound coming from the area of the
bottom (drive) wheel.? Further examination showed that the
blade was riding far enough out that it was scraping the
inside of the blade cover.? Thinking that I just needed to
adjust the tracking (something I haven't done since buying the
saw), I started in on that -- but quickly discovered that the
blade was riding properly on the upper wheel.? Not quite
touching the flange.
Some additional experimentation showed that the drive wheel
tracking problem is eased when I reduce the blade tension a
bit.? I don't think I'm overtightening the blade and bending
the frame -- I'd think the upper wheel would be more affected
(but I could be wrong about that).
I'm not hearing any noise from the drive shaft bearings so
think it's unlikely they have worn enough to cause these
symptoms.? Maybe I just noticed something that is common to
these lightweight machines?? On the other hand, if the problem
is flexing in the drive shaft, that could be a recipe for
metal fatigue and eventual failure.
Comments?? Has anyone else observed this?
|
Right now McMaster-Carr has ABEC-3 6062-RS bearings for $13.11USD apiece.? ABEC-1 bearings are $6.28.? The maker(s) are not specified.? McMaster is one of the fastest shippers I have dealt with.? Probably not true for folks outside the US.
BTW, the manual for my HF 4x6 does call out the bearing types for the drive shaft.
Mark
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Few comments on bearings - Deep groove bearings
10mm and above are covered by ISO standards with radial internal clearances designated, in order of increasing clearance, as C2, ‘Normal’
or CM, C3, C4, C5 & C6; while bearings less than 10mm are considered
‘miniature’ and the clearances are designated MC (for Miniature Clearance), MC1
MC2, MC3 MC4 etc.? MC3 is considered the
equivalent fit to Normal (thought the actual clearance numbers are
appropriately smaller
- ABEC scale is a
bearing industry standard for manufacturing tolerances on every measurable dimension
except radial internal clearance. Higher ABEC ratings allow those
bearings higher operational speeds, in excess of 30,000rpm, but no more load
and even less shock resistance. ABEC 1 are cheap and fail?more?quickly, these
are what you will get if you do not ask for better. ABEC 3 or 5 are usually
better manufactured and still reasonably inexpensive.? You’ll pay 5-10x as much for ABEC 7 or 9 for
absolutely no measurable difference in performance over ABEC 3 in a 4x6. You
can even buy an ABEC 9 bearing with C5 radial internal clearance (for high
speed roller skates) that is worse for side guide rollers than a much cheaper
ABEC 3 with C3 radial internal clearance.
Right now McMaster-Carr has ABEC-3 6062-RS bearings for $13.11USD apiece.? ABEC-1 bearings are $6.28.? The maker(s) are not specified.? McMaster is one of the fastest shippers I have dealt with.? Probably not true for folks outside the US.
BTW, the manual for my HF 4x6 does call out the bearing types for the drive shaft.
Mark
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??? ??? ON the HF site now of you look up a 4 x 6 you get one ,
then you pick to look at the manual & then there's 4 to pick
from . Either the 3rd or 4th one is what my original saw was . Of
the 4 manuals they only list the bearing part #? the? 6xxx type
bearings for the wheel shafts , the guide bearings show a longer
part # 180029 not the actual bearing number like the 6xxx bearings
,. They also show some bearings have the shields "Z" while others
don't . ON both of my saws all the bearings were 6XXXZ bearings ,
shields on every bearing . They also show 3 seals on 1 or 2 of the
saws & just 2 seals on the other saws . The older saws like my
original did have 3 seals , just they were installed in the same
place & all 3 the wrong direction . I would have thought that
after all these years? they would have at least have the 4 x 6 all
figured out ,? I couldn't tell you which parts list matches the
saw I have , I don't think there was a part # will have to look
for that next time I get over to the shop .But I guess it's still
a " work in progress " .? I'll have to look at what # the seals
are that I bought extras of & find some place to post that
info . Maybe there should be a list in the files section where we
can note the bearing actual #'s along with the seal #'s ?
animal
On 2/15/2022 4:41 PM, Mark Kimball
wrote:
toggle quoted message
Show quoted text
Right now McMaster-Carr has ABEC-3 6062-RS bearings for $13.11USD
apiece.? ABEC-1 bearings are $6.28.? The maker(s) are not
specified.? McMaster is one of the fastest shippers I have dealt
with.? Probably not true for folks outside the US.
BTW, the manual for my HF 4x6 does call out the bearing types for
the drive shaft.
Mark
|
I have used my HF band saw very little in the two years that I have owned it and I recently need to saw some 1 1/2" square 16 gauge tubing. About halfway thru my second cut, the blade just stopped! I began checking out the various things that would cause this ( not very many) as the motor still ran. I pulled the cover off of the gearbox and low and behold, their was not one drop of oil in the gearbox and no indication of any leakage. $52.00 later I had na new brass gear and a valuable lesson learned. Just because you bought it new doesn't mean it was properly assembled. Take the time to check the gear box lubricant!
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I thought it was standard practice (with these saws) to empty that out as soon as you get it and clean all the grit crap out of it and put in fresh lube. The stuff in mine had turned into a very thick paste with all the grit in it,sort of like lapping compound. I saw photos somewhere a guy found a bullet in his gearbox.
--
null
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??? ??? If it's not it sure should be . I don't know how but
there should be some kind of warning that new members get when
they join he group . Gotto wonder how many saws would still be
cuttin if folks would have only checked the gearbox oil ?
animal
toggle quoted message
Show quoted text
I thought it was standard
practice (with these saws) to empty that out as soon as you
get it and clean all the grit crap out of it and put in
fresh lube. The stuff in mine had turned into a very thick
paste with all the grit in it,sort of like lapping compound.
I saw photos somewhere a guy found a bullet in his gearbox.
-- null
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On Thu, Feb 17, 2022 at 07:59 AM, Robert Terrill wrote:
Just because you bought it new doesn't mean it was properly assembled. Take the time to check the gear box lubricant!
My HF saw is about 3 years old, and I've been meaning to check the oil since it was new.? Having to tilt the machine in order to keep from spilling the gear oil is the reason I kept putting it off, but this thread finally got me to do it today.? And I'm glad I did!? The gearbox wasn't empty, but it was pretty low and the gears weren't getting properly lubricated.? I had the saw tipped so that the gearbox was maybe 10 degrees off of horizontal, so I filled it as far as I could without spilling and buttoned it up.? I figure a little bit of headroom was probably a good thing.
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I removed the blade on my saw so I could mess with the drive wheel to see if there is a lot of play in it.? I didn't observe much, if any.? But I'm not sure how little it takes to cause a tracking problem.
Mark
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Hi Mark,
A while back I had issues with my blade coming off. What I found, as I cut any thing with my saw, metal wood plastic, I looked at the blade wheels & they had swarf on them, so using a hi tech scrapper…6” rule….to remove the swarf. The top wheel took a bit, the bottom IF you are careful can be done under power, obviously remove the blade! The problem went away. Not saying that it will fix your issue but an easy fix,
Cheers Kerrin
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Hi Kerrin,
That's worth checking.? Thanks for the suggestion.
Mark
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Hi Mark You won't necessarily see or feel any 'play' because the inner bearing is generally OK and holding it steady but you can make it readily apparent with an 18" strip of aluminum angle or wood to which you fix some small magnets and apply to the rim of bottom bandwheel
I removed the blade on my saw so I could mess with the drive wheel to see if there is a lot of play in it.? I didn't observe much, if any.? But I'm not sure how little it takes to cause a tracking problem.
Mark
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Hi Mark You won't necessarily see or feel the failed bearing as the internal damage to the bearing is often not great, but you can do a test that makes it readily apparent. Take ~18" length of 1/2"x1" or -1/2" aluminium angle or a stick of wood and glue neo-magnets to one edge, 6" apart at one end of the stick. Apply the magnets to the rim of the bottom band wheel inside the blade teeth and angle the stick so the top of it sits next to the sawframe casting (pic 1 - sorry about the?cluttered?background). As you release the tension?in the blade the top of the stick?will move outward away from the edge of the casting. (next two pics) If the outboard bearing is OK it will only move about 1/8", if not it will move much more.? The pictures show how much the top moves with?good? bearings. I'd be willing to bet that yours will move more. I used magnets with a bit of threaded standoff as its easier to clear the edge of the casting and to mount to the Al-angle, but ordinary button magnets, superglued on will work. (pic 4) Crud build up on the wheels is a real problem?especially if you use coolant?which binds the swarf into a paste, but that doesn't?happen all of a sudden. Not that bearings fail instantly either, but it's a lot quicker than the crud build up - jv
I removed the blade on my saw so I could mess with the drive wheel to see if there is a lot of play in it.? I didn't observe much, if any.? But I'm not sure how little it takes to cause a tracking problem.
Mark
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I had a tracking problem for the past few years, and nothing I did helped (the blade I was using during that time developed a lot of cracks and finally broke).? After replacing it, I recalled someone saying that even if you thought the blade tension was good, it probably wan't.? Taking that to heart, I *really* tightened the blade, and the tracking is now great.
-Dave
On Saturday, February 19, 2022, 01:04:37 PM PST, John Vreede <vreededesign@...> wrote:
Hi Mark You won't necessarily see or feel any 'play' because the inner bearing is generally OK and holding it steady but you can make it readily apparent with an 18" strip of aluminum angle or wood to which you fix some small magnets and apply to the rim of bottom bandwheel
I removed the blade on my saw so I could mess with the drive wheel to see if there is a lot of play in it.? I didn't observe much, if any.? But I'm not sure how little it takes to cause a tracking problem.
Mark
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Though I don't understand the circumstances properly, it obviously?worked? for?you, Dave Generally, increasing tension makes the blade track away from the rims of both wheels because the tension takes out the play in bearings and bends/flexes the axles of the bandwheels. If you can make the band track on bandwheels without the guides in place, it will track with the guides in, as twisting the blade seems to make the blade track toward the rims - jv
On Sun, Feb 20, 2022 at 6:27 PM Dave Seiter < d.seiter@...> wrote:
I had a tracking problem for the past few years, and nothing I did helped (the blade I was using during that time developed a lot of cracks and finally broke).? After replacing it, I recalled someone saying that even if you thought the blade tension was good, it probably wan't.? Taking that to heart, I *really* tightened the blade, and the tracking is now great.
-Dave
On Saturday, February 19, 2022, 01:04:37 PM PST, John Vreede < vreededesign@...> wrote:
Hi Mark You won't necessarily see or feel any 'play' because the inner bearing is generally OK and holding it steady but you can make it readily apparent with an 18" strip of aluminum angle or wood to which you fix some small magnets and apply to the rim of bottom bandwheel
I removed the blade on my saw so I could mess with the drive wheel to see if there is a lot of play in it.? I didn't observe much, if any.? But I'm not sure how little it takes to cause a tracking problem.
Mark
|
I've found that until you hit on the answer, increasing information about a problem sometimes leads to increasing confusion as well.? I think I'm in that part of the learning curve right now.? I performed John's recommended test for bandwheel deflection, but used a laser pointer + magnetic base attached to the bandwheel instead of a physical lever arm.? For an optical lever about 18 inches long I observed a little over 1/8" deflection as I tightened up the blade.? This suggests that the bearings are OK.
I also checked to see how gunked up the bandwheels were, and was pleasantly surprised to find that they were pretty clean.? I generally cut aluminum dry, and that's what I cut most often so there was little to no accumulation of swarf.
John's comment regarding the guides has me wondering if they have something to do with my problem so I will fool around with them to see what happens.
Something else I'm going to do is remove the blade and place a straight edge across the bandwheels to see how much offset there is between them.? I don't see how that could change over time (particularly if the bearings are OK) but, hey, maybe I'm not confused enough yet :)
Based on a previous extensive discussion regarding blade tension I started using higher blade tension and that roughly coincides with the time I noticed the tracking problem.? So who knows when it really began.
Mark
|
Ahh... new information and old assumptions...?
If this only started when you increased the tension then it could be just a blade tracking problem, though teeth scraping the blade guard means the blade is riding pretty far out on the bottom wheel. The only way I can think that it would ride this far out when the tension?is increased, is if you've tilted the top wheel too much.
The blade tracking process is as follows (with apologies to John Pitkin, as it doesn't quite follow his instructions): Tracking on the top wheel is by tilting it, so the blade runs back toward the rim.? The wheel should only be tilted to get it to track close (<0.040") to, but just not touching, the rim,?no matter what happens to the tracking on the bottom rim.? Then the bottom wheel is moved in or out on the drive shaft to get it to also track <0.040" from its rim.? You do this by changing the length of the spacer between the bottom wheel and the gearbox out bearing.
If you've tilted the top wheel too much but not tensioned the blade enough, the blade can be made to run within 0.040", but then increasing the tension will drive the blade toward the top rim. This action actually bends the blade even more across its 1/2" width, which it resists; so the rest of the blade, which is also looped around the bottom wheel, wants to move outward and can scrape the blade?guard.??
Begin by de-tensioning the blade and removing all the tilt from the upper wheel tracking mechanism, then give the tilt screw 2 full turns inward. as the starting point for tracking.?? Re-tension the blade to full tension and fine tune the tracking to get it to just not touch the top wheel's rim
With any luck it will track properly?on the bottom rim now.? If not, then move the bottom wheel out until the blade tracks on the bottom rim too.? If it is so far out that the blade scrapes the guard still, then I can't?help but think?you'll have to change the bearings just to see if that is still the original problem?- jv ??
I've found that until you hit on the answer, increasing information about a problem sometimes leads to increasing confusion as well.? I think I'm in that part of the learning curve right now.? I performed John's recommended test for bandwheel deflection, but used a laser pointer + magnetic base attached to the bandwheel instead of a physical lever arm.? For an optical lever about 18 inches long I observed a little over 1/8" deflection as I tightened up the blade.? This suggests that the bearings are OK.
I also checked to see how gunked up the bandwheels were, and was pleasantly surprised to find that they were pretty clean.? I generally cut aluminum dry, and that's what I cut most often so there was little to no accumulation of swarf.
John's comment regarding the guides has me wondering if they have something to do with my problem so I will fool around with them to see what happens.
Something else I'm going to do is remove the blade and place a straight edge across the bandwheels to see how much offset there is between them.? I don't see how that could change over time (particularly if the bearings are OK) but, hey, maybe I'm not confused enough yet :)
Based on a previous extensive discussion regarding blade tension I started using higher blade tension and that roughly coincides with the time I noticed the tracking problem.? So who knows when it really began.
Mark
|
John Vreede
Jim Frame
