Thread: Dressing bandsaw tires, a sure method of truing the wheels + an edge question for ye

Hello again folks, only getting back at this now as the weathers been good.
After some pondering and procrastination, seems with this contraption like I might, just about... be in with a a shot of bodging this!
(bearing in mind this is optimistic, to say the least.)
Too early to say if it'll work or not though.

Getting some use from my pillar drill
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Nasty stuff to cut, plenty of oil needed for the dust
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Turned on the lathe with a wooden mandrel thereafter, and cleaned up with remounting on the 30mm bit, as I have only a cheap lathe with no chuck
the pillar drill is more accurate to bring the three surfaces to better tolerance, and should'a drilled the four holes after instead of beforehand...
Just incase I need make another.
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Drilled and transferred graphite on wheel rim..ground a point on some thread for marking.
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Drilled appropriate sized holes for router bit and wheel retaining bolt
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Upon testing the jig I noted a tight area, but seemingly not regarding the circumference and possibly just a little area on the inner part of the wheel.
I should note that the front bearing is still tight, I swapped it out for one of the old ones I had.
I don't think I'd be in with a chance with this otherwise.
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Marked out the bore to see if something might become apparent, not even a hint of something obvious
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This is a job where your knees are best not in a heap from landscaping.
Very easy to cock the contraption whilst boring to depth, don't lean too heavy.
Turns out the little bit of the plank overhanging makes lovely handles.

Getting past the original spec bore, to get into the wallowed area, means I may need to make another bore insert
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Cleaned up and full depth, taking nothing off anymore
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Taking another lick off it with some masking tape, back to boring it to depth again, being even lighter handed than before.

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Another lick, hoping to get the tool to drop into the bottom without needing to be well worked down into the bore.
Still messing around yet, and likely will have to make another tool.
I've got an outer race which I'm testing the fit with.
I'll keep ye posted
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Tom

With a bit more pondering, after forgetting the wheel retaining screw was present underneath and pulling up the bearing through the bore...
I thought it might be likely more helpful for others who don't have the luxury of having one bearing seating well, and perhaps myself also,
if I had a go at possibly improving matters, and seating two more of these old bearings for more surface area ...
and perhaps for interest sake also, having pondered if the races could be used for extra rigidity, though there is 0.4 of some sort of shim needed if so,
as there would be slop in-between the circlips.

Not that I noticed any slop with the single bearing, but that perhaps it might be legitimate a reasonable bodge for others..should this work.
Also thinking I might notice a ridge whilst inserting the shaft, but no hint of anything there.

Took out the bearing to photo
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You might make out a pair of score lines from pulling the bearing through.
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Hoping to get witness marks mostly on the bottom/deepest area, as I reckon it might be slightly tapered at this point.
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Needed to use the wheel retaining washer to plunge the tool deeper, (I made a heftier one which wouldn't warp)
and got a bit greedy, tape slips and mushes up, clean and repeat.
This might be a sign that I was removing the deeper area, still unsure really, and I filmed and watched again, still none the wiser.
Likely needs another lick, and possibly some selective removal, but will be cutting the stainless steel shim stock of sorts to see what the fit is like, before proceeding further.
Will edit this later with a screenshot or two.
Tom

That middle isle special done the trick, turns out to be very nice to work with once formed by the bearing and wheel bore.
It seems to be somewhere abouts 0.4mm
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Notable to see how it stretches when fit
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Fit seems good at the start.
Jig rotated clockwise, two choks on the right of the wheel to brace against, and a wedge of sorts on the left .
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You can get a better idea of things when the sleeve is formed
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Flipped around to make sure, that there is indeed a taper at the bottom
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Progressively taking cuts from the bottom only, by way of narrow strips of abrasive,
Didn't require the bolt and washer much beyond the first bit, and instead hammered with both my fists to insert the tool into the bore, and not being too greedy, having took more passes with the last depth of cut @two strips of masking tape
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That extra wide bearing from the motor was nice, as it also has a smaller inner race for knocking out again.
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The last little lick with a third layer of masking tape targeting only the bottom was needed.
My boring tool was seemingly not round, so noteworthy as one can take half the depth of cut, compared to something accurate which would have complicated things removing twice the amount in one pass!
Also worth noting you get careful you don't peel off the masking tape when the abrasive has dulled.
Thorough cleaning and vacuuming of things before doing so, colour in the bore again and all the rest.
Let's just say, that shaft got a bit of the patina removed by doing the job.
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The sleeve didn't wish to sit below the cir-clip, so took a few more final licks to seat it deeper which didn't make much difference.
Probably a bit of twist of the sleeve, and I stopped there regarding getting the bearing sunk home.
Instead I took a file to it, and make sure it was below the slot for the circlip.

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A shot of the bore with newly cut shoulder.
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Tom

Two old bearings were utilized for their outer and inner races for spacers,
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And my newish bearings installed again
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Lots of anticipation to see if my bodge worked, quiet as a mouse, which was at least one thing off the list.
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Went ahead and repeated my "bore checking test" which just might be a red herring,
as I got the exact same reading again!...
Perhaps it might highlight something, but that'll likely take someone with an old Centauro to find that out.
I'll explain why that's news to me in a bit
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Trammed the face of the upper wheel, to see if things might have been better or worse, or unchanged.
The largest discrepancy was the thinnest Shinwa rule I had which was 0.5mm.
The opposites most consistent was the noted times I've pictured before.
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Went ahead and marked a new line out, not sure if it was exactly the same as I ripped the tape off.
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Trammed the lower wheel, around half the Shinwa rules discrepancy
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So time to check where the rubber meets the road, but not the rubber as it were, as I could'a dressed those out'ta whack.
Flipped the wheel over to check the little ridge of cast instead.
There was no flutter between guides. and if there is something I'd reckon it would hopefully be possible to be dressed out,
I'm leaving that out for the minute yet, as I wish to get a true reading from this alignment method, which as far as I can make out is the only way to do it.
For interest sake I also trammed the back face of the upper wheel, and noted less than the lower one.
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Seems I'll have to leave that for the next post, which I'll have to get back to ye with.

Cheerio
Tom

Here's the last of the testing regarding the back of the upper wheel, there seemed less discrepancy of that face than the lower wheel.

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Flipped the wheel around again, and got thinking how I'd approach dressing the face of the wheels,
marked out some high spots to get started.
I think this shot might highlight why I didn't think to check this earlier, as there are apparent tool marks,
though possibly some kind of spring loaded grinder of sorts I guess, which could ride over large lumps of casting slag or dross.
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This turned out to be a terrible idea, the file just coasted over the bumps, and I finished where I started.
I probably cut some precious weight from my wheels, wah wah.
I'd say I might have removed over half a mm doing so, I hope it was no more than that, and will pretend so.
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Looking back at my pictures, seems I didn't go as far as I thought, but still excessive, and I would have liked to see the last low tool mark or two.
I won't be doing that again, as I bet I made at least a half hours for myself.
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Turned out some spot filing was the thing to do, but not with any old handle,
it must be the right height or the outer edge will be very excessively proud, by a lot,
Still was able to end up with the OD edge either bang on or proud, thinking the hand filing might do the opposite
and wipe out the proud edge which is a valued thing for being accurate.
Arrows marked to make sure I don't do a numpty, and the work done on the left side of the wheel, in order to draw file this cast iron in the correct manner.
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Now I've got the hang of it
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I should mention also that I tried some nice 120 IIRC Mirka sandpaper on a block, but the wheels just seemed to polish the stuff, but not cake either.
Perhaps that roughly 2" block had too large of a surface area to apply any force to the material.
Maybe the end of a file might do something, but I'm leaving it at that, as it's far better tolerances than the best face I've trammed,
and I reckon the length of timber for the beam to register against won't see that.
Eager to see what the readings will be, and should probably check before dressing the face of the bottom wheel.
Fingers crossed I've done a good job, and there's not some other variable at play.

That's it for now.
All the best

Tom

Eager to test this and was very pleased, though there was still slight discrepancies, I didn't find those straight away
It was apparent things were getting very close, so I decided to take a final pass again with an affixed tool, but not like the last time...
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It took doing the lower wheel before finding that out, so I might as well post some of those pics also
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About half the 0.5mm Shinwa rule of discrepancy
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Tip o'the marker, right next to the noise.
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Needing to keep clean at this stage
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Fine control of the tramming saw plate with ergonomic handle, long enough to keep square, but also to knock
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Spent a little time checking the pulley, which was now inserted on the shaft, as I still had some inconsistency, so double checked alignment,
and was to find out a bearing works very nicely for this job
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Fingers feeling for flush at the back side of the stick
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Pressure applied as such, making sure its pressing on a high spot on the wheel.
This took ages as it didn't see any progress.
TBH I should have changed to a finer file before proceeding,
but a large square file might shine here, dunno?
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Tom

Around here I decided to make sure everything was setup getting ready for test running.
With my new belt it was more notable it was needing more accuracy regarding co-planar, or perhaps a more precise term, in-line with the chassis,
and a quick lick of dressing to ensure my bodge repair was concentric was done
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Noted excellent results on a test run, as in flutter and fore and aft movement of the blade, reduced to nothing, guides set a hair away now,
the most visible fore and aft became the best,
but much shaking was apparent, though tested later at a scorching 25c seemed to calm down.
I was planning on dressing these tires anyway, but now with the wheel face trustable, it was noticeable the rear of the tire needed some removal.

Time for another round of dressing, which needed more than a quick lick.
What was stalling me was I didn't want to make my parallel in width plane irons any narrower, since they've already done this 20 times before,
and were rightly dulled on the sides.
So I went back to the original beater plane, which is tapered from using t'other end for all scraping tasks,
(which can deeply score the underside of cap iron when paired back, so care needed to assemble it differently afterwards)
and utilized a wedge shaped for this plane iron
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Making sure it was parallel with the block
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Getting the wheel 90 to the block wasn't quite as easy this time, as I didn't want to get a blade on, and wrangle it to get the upper wheel where I wanted...

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Few layers of duct tape, (laid down on top of the protective masking tape which does a good job,)
was no bother.
I was thinking it might bunch up under the block,
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Figured out this is the way to do it,
Soooo much easier, a doddle compared, and less likely to cut into the tire this way.
Very fine adjustments possible and easy/nice to retract aswell!
Why didn't I do this sooner?
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Can really get some work done like so.
Changed tack with the placement of me hands, can use both hands on the RHS of the machine, provided one removes the bolt for the door catch.
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I was kinda expecting the fore and aft to return again, with the thinking more emphasis being on the front edge of the tire,
but seemingly no difference, though hard to know due to the heat the last few days.

I've got some videos I'll try uploading, though you can't see much vibration, you can hear those bearings a'groining.
Having taken the wheel off before this, I now noticed some play in the front bearing,
so it looks like I'll have to have a crack at that now.
Not being too confident in my bodge repair yet, and perhaps less so if you heard the noise,
but seems it's worth a shot, seeing as I might learn some more bodgery along the way having done it before.
Perhaps I'll get things better than before, if it is infact also troublesome.
This will hopefully work in a bit, linux keeps crashing uploading youtube.

Test run - YouTube

Cheerio
Tom

Hello again
Guess most of ye folks had enough of the misery, at least I can report things seemingly went well regarding the sleeve
in the front journal this time round, infact I reckon I done a better job than the one at the back.
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Driving the tool into the bore, plenty of tape sacrificed, as I didn't wish to open up the area outside the retaining circlip.
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The abrasive tape joint in the middle, so you can watch the joint should/when it binds.
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Not taken any screenshots of this yet, as I'm not sure how this will hold up to encourage such shenanigans,
but the piccies should explain most of it...
Couldn't get to the bottom of this without taking excessive material from the middle area, so had to change tack.
Removed one of the bearings and made a wee 2.5mm shim for under the puck, to get the shoulder a smidgen lower.
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Using narrow strips of tape targeting removal, see the tape walked and then froze,
A bit of a guessing game when it's in the bore, and with this second depth of cut (masking tape underneath)
it's less of a battle than the first depth, so going on feel and sound.
If I'd taken the bearing out sooner, I probably coulda used wider strips which don't walk up the tool so much.

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I didn't take a piccy of the amount of this abrasive used yet, but kept most of the strips to see how much it took.
Having trouble with youtube.computer to upload this job, and early days yet to see if this speedi sleeve of sorts will hold up.
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I can add some more pics of this later on or whatever, not much difference than the first time round.
Machine runs fairly smooth, taken some videos,
Not totally so, but not noticeable on camera and less so now in real life, with the table installed.
The little bit of it was probably there beforehand, I woulda presumed if the blade wobbles, then the saw would be expected to have that anyway.
SAM 7984 - YouTube
Been doing some more work and bring things up to date
I'll get to that soon.

Tom

Hi again, brought ye up to speed now, if you've seen the video, evident lack of beam tension, yet the saw blade is running about as good as can be.
Seems I've been chasing a big red herring all this time, and after a heck of a lot of trial and error, it indeed seems the case that infact no bandsaws out there actually have flat tires!

I'd been doing plenty of messing about with upper wheel chassis protrusion, so am pretty confident to say this,
though I could try dressing the tires properly again, should they possibly be improved upon,
I did find the top wheel had a bit of extra meat when dressed again, so that 0.5mm runout of the upper wheel did throw things off a bit.
Haven't dressed the edge again, but I reckon it's likely that the edge is sound from the last time,
and I guess the lower wheel isn't too bad, since it had half that runout, none the less went at it to see,
but only the briefest of licks, and found I couldn't get as accurate as I'd have liked without a load of faff.
Attachment 527292

Done near every experiment on this machine by now, with no noticeable changes.
Might have one more go at seeing if by miracle the teeniest of adjustments might improve, highly doubtful
but it's work that I might as well do whilst preparing for the finale.
Made up another heavy wheel retaining washer, rather than winging it with the old ones which might be a bit variable,
this is the level of insanity what I'd been reduced to doing before those recent things like finding out the faces of the wheels wern't accurate,
and as such alignment and tire profile were thrown off

None the less I likely have a smoother running machine because of all that, and it'll be a breeze to get things like what they should be,
which I must admit... seems a little too easy that this will solve "everything" but I do recall this machine actually cut well occasionally, though still temperamental at best.

So might as well do the littlest of things to finish up mythbusting to the best of my abilities, the thought of having flat tires.
For anyone still skeptical of my findings, and perhaps are of the opinion the machine setup could be improved,
I have some good evidence to back this up, which I was sceptical about, even though I had the real answer all along.!
Might as well post a piccy of the ACM promo video on YT, featuring other questionable statements that give the impression
there was some misinterpretation.
Probably not enough to go on a wild goose chase for a normal person! ....
Screenshot-2023-6-14 ACM 440 Bandsaw Range - YouTube.jpg


Here's the other clue, from a good old Centauro manual, arguably the leaders in the business.
The below quote had also been suggested to me when I started all this dressing malarkey.
Taken from the best Italian bandsaw manual I've ever read by a long shot.



" MAIN TROUBLE AND RELATIVE REMEDIES "


The blade moves very far back when it receives the cutting force
- Insufficient flywheel seal convexity, notify the technical service of the area dealer.

The manual..

http://intervesp.ddns.net/?sitemap/f...o/SP0305gb.pdf

So fairly clear to me now that a flywheel ring seal is actually referring to the tires.

For the heck of it I decided to measure the replacement for the Centauro CO600, as it's the only one I found which was a strech on tire.
I didn't look at it twice previously, as I didn't seem impressed by it, and was trying to avoid using it TBH as to have a spare/plan B.

Looking at it again, now it's apparent why I've heard of "true flat tires"
...helps having watched some portable sawmill videos on YT, which explain an opposite crowned profile in which the blade conforms to, whilst
whilst bent into a radius, so in effect like two cambers meeting in the centre.
(I think this might be a differing story concerning huge resaws)

Perhaps the first glance of the tire might explain better...
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Better shot of the dressing
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Here's some measurements of it for ye
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Only when tensioned does the camber become apparent, appears to be of a similar profile as to the machines that run without tires.
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So looks like I've got some work to do knocking off the corners.
Fingers crosses I can report back with some excellent results.

All the best
Tom

Hello again
Took some more time to properly inspect this spare Centauro tire
as I was still a bit doubtful of the profile I was seeing, so jerry rigged up something to account for the tongue underneath.
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Seems like the apex is 17.5mm from the front edge to me
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So I copied that profile onto a bit of saw plate
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Marked out a a line for the apex
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Improved the scraper mounting block, since I had a profile to deal with now...so no skewing allowed.
It's so much easier to use, that I reckon I'm only getting the basics of things sorted now.
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Alignment with duct tape for one axis....
I didn't take a picture, but what's missing is the ali beam featured again, to make sure that upper wheel is in-line with the chassis.
You'll have to take my word the block is aligned with the wheels now
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Lowering the upper wheel for depth of cut
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Continued....

Howdy folks

Dressing this profile certainly wasn't as easy as I'd expected...
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Seems I kept wiping out the apex no matter what I did...
I increased the camber, and even still was getting inconsistencies, as the tool was blunting,
and the only sharp edge left was the apex, so found out better to knock the edge off at that point.
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Dressed the tire on the lower wheel, and revisited using a feeding system for advancement of the cutter block

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Getting somewhere now, as the apex was remaining
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But still had a bot of trouble with the upper wheel...
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That's the bit where I figured the upper wheel wasn't exactly plumb
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Now getting a clearer picture, not much in that now, noteworthy I took a'lil too much of the rear of the tire,
which doesn't matter much as the apex of the camber isn't centred, well not on Centauro's anyway,
so no flippin the wheel around for a quick bodge!
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So revisited that same piece which I couldn't cut, same blade,
and it was just about cutting, which was much much better than before, but not great.
Turns out it was still real good for crosscutting though, hrmm?
Seemed good enough excuse to try out yet another blade for testing.....

Very pleasing results were obtained,oodles of beam tension!.. and no hint of burning fumes,
This 3TPI blade likely cutting as fast as could be expected, no spelching from the underside,
The remaining vibration seems to have gone, I'd say a lil sawdust might have helped things.
Took a video of the cut, but seems my computer has had enough of youtube.

So, dare I say that seems like the jobs finally done on this machine.
This thread was a wee bit of a slog, though I learned so much that I'll be keeping my eyes peeled for another
machine to restore, since all of those mystery's have been solved.

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All the best to ye, fellow bandsawyer matey's

Tom

Just to add I measured that spare Centauro tire yesterday, it's 37mm wide, so there's 1mm in the difference from apex to centreline.
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Managed to figure out I can upload to Dailymotion, as youtube has stopped working.
Not able to edit videos or anything due to my "unsupported browser"
so not much point in sticking the wheel bore repair videos up, besides I haven't give the machine a through testing
as I've got other work to do.


Private Video - Dailymotion