Bandsaw wheel non shouldered bore

[Tom Trees]

Hello folks
Hopefully this will be the end of my Centaurolization attempt on my old Italian bandsaw. :rolleyes:
After tracking down the cause of upper wheel wobble to this, it seems I need to address the spacer issue I'm having.
This is the rear of the wheel, and that bearing has some space to wander until it butts against the retaining clip.

A clue might have been that the bolt never cinched down on the washer holding the wheel/bearing in place.
As in the inner race was free to move about, and the washer does not have any say in the matter.

471277

471276

471278

Noting that the Centauro's of old, have a big washer which looks to capture both races of the wheel, I wonder what kind of spacer is in those wheels.
That is.. if those wheels have a non shouldered bore?
If not I question if things are still the same with new machines, and if also a non shouldered bore...
Is there a better way of doing things, as that orange spacer seemingly isn't up to the job.

Some Centauro machines of old have washers that seemingly might compress or at least align with both inner and outer race,
with possible a thou more contact with the inner race?
471279

471280

471281

Compared to my machine where the washer which would only have contact with the inner race...if the spacer was wider, that is.

https://sawmillcreek.org/attachment.php?attachmentid=471283&stc=1&thumb=1&d=1641701850 (https://sawmillcreek.org/attachment.php?attachmentid=471283&d=1641701850)
471286

Looking at Jack Forsberg's videos earlier of work done to the Poitras (non shouldered bore) spacers and bearings.
I couldn't find recent activity on his local forum to question him about it.
Here is a look at the bore
https://www.youtube.com/watch?v=Bza0WiKMckE
I'll skip to the more important aspect of the spacers which Jack covers
https://www.youtube.com/watch?v=gRX4b12tGtI

I see a cast hub with a raised ring to press against the outer race,
Seems he has two spacers made of cast iron and the inner spacer is a thou wider.

I wonder what would be the best solution for me, as I don't see any wear on this orange plastic/rubber spacer,
and I guess things could be improved.

Love to hear some suggestions, especially you folk with Centauro's which possibly has a better system,
as I've not read anything about this before, nor can I find anything but Jack's posts on the subject.

Thanks
Tom

[Mitch schiffer]

I don't have experience with this particular machine however I used to do industrial maintenance in a foundry. I have replaced quite a few bearings during that time and several machines had a similar setup with no shoulder. None of the bearing carriers that I have worked on without a shoulder all had a spacer that referenced off both the inner and outer race. Conversely bearing carries that do have shoulders don't always have a spacer for the inner race also. I'm thinking that the design of how the bearing carrier is set up is probably not a major factor in you wobble issue. You could test the shaft for runout with a dial indicator when it is assembled. This will tell you if the wheel or the shaft is the issue. Also if both the top and bottom wheels are that same you could switch them and see if the issue follows the wheel. While you have it apart I would put new bearings in they are cheap enough to just replace while you have it apart, and that will also rule out a worn bearing as a possible cause.

[Tom Trees]

Thanks Mitch
This is definitely the issue, as I've done a lot of work taking everything else out of the equation.
Not checked for runout as the wheel can change position, so a bit pointless, not noticed any wobble whatsoever thankfully,

Have dressed the tires with a fixed tool and thankfully it's spot on in regards to being centred, i.e taking consistent light shavings from the tires.
Carriage assembly made rock solid now also, and cant swap wheels as the bottom has a track for the belt.
Shaft seems good to me, no scoring or anything, and evidently still tight.

I would love to know what material those spacers were on the machine you worked on, and if that was a single spacer with contact of two races, or if a two part design.
friction fit, would be keen to see roughly how much of a gap between them is best.

Thanks
Tom

[Mitch schiffer]

All the spacers I have seen are steel. Most of that equipment was large industrial stuff made for the though environment of a foundry, so I'm not sure if plastic is used more commonly in the smaller lighter duty equipment. I'm not sure if I understand what you are asking about the 2 part design but they were almost always a single peice and only referenced off the inner race. We never installed them with a gap between the spacer and race. It would be pressed in tight usually with a arbor press.

[Tom Trees]

Thanks Mitch
Glad to hear that steel is used for some applications, as I had an idea that the cast spacers on Jack's Poitras machine
was used for its lubricant and wear properties.

The wheel was definitely on as far as it will go, or at least beyond the end of the shaft, as the washer which seemingly should make contact with the inner race
doesn't.

I could just shim from the back with a washer as it's the only bearing which can slide,
That is the pictured bearing can be lifted up as far as the retaining clip, (no further) and drops down to the witness mark, so about a heavy 1mm of slide.

but then the outside race would not be in contact with the retaining clip, which I guess would most definitely be a bit of a cowboy bodge.
It would be the same deal regarding the front, i.e putting a washer with 30mm bore behind the retaining washer, the outer race would not make contact then,
plus the fact that the front bearing presses down to a perfect depth, and no deeper, and it's seemingly nice and tight.

Thanks
Tom

[Tom Trees]

I've been looking at more saws and have noted the retaining washer in the Centauro's and also the newer SCM formula's
are seemingly large enough to press on both races.
A Centauro CO 600 from 2001
471363

And the newer SCM formula's
471364

I'd really like to know whether these saws, or similar Italian, or other European machines or indeed anything of a similar design, also have non shouldered bores.
Just to get an idea should there be two spacers for each wheel,
(spacers for both inner and outer race) which could hopefully be made from some pipes rather than machining a solid chunk.

Hopefully someone can advise.
Thanks again

Tom

[Tom Trees]

Been looking at various machines, and seems like I might be getting somewhere.
Of all the Italian or Italian(ish) saws similar to mine, the Centauro's have been the only ones I've seen so far, that have the larger washers.

Looking at the slightly more industrial SNAC model similar to my star/SNA model, and noticed this on the table.;)
It does look like it could be a spacer for an outer race, but that is only an assumption, but possibly a likely one, since the machine is being run without a blade.

https://www.youtube.com/watch?v=EVLR9Jomtng

Might pester this guy and see what I can find out.
Eager to see if it's a snug fit, and also what the fit of the inner race is like.
Also curious to know if both spacers are the same, as the machine also has a small washer, guessing only in contact with the inner race.

EDIT: False alarm!That was just a roll of tape on the table, LOL! :p

Tom

[Bill Dufour]

Photo #3 shows a groove for a internal snap ring. I do not see that ring anywhere in the bits and pieces?
Bill D

[Tom Trees]

I've only taken off the one snap ring Bill, the other is still holding the front bearing into the hub.
Been trying to find a SNAC manual to see if that is a spacer on the last video I linked to, and also questioned this in the comments.
Thought I might have found the answer in the manuals, but unable to find a SNAC one, as on my manual, the only spacer is the one I've shown,
and seems to be also the case for similar upgraded SNA machines your side of the pond.
Thought that might possibly be an extra.

Going to try finding some Centauro or SCM manuals to see if two spacers per wheel are mentioned.
Worth noting that the formula 440 seemingly is also the same type arrangement using a small washer, differing from the larger ones.
This design seems more common, as I've looked at all of the brands of premium saws, and can only find Centauro, SCM and the old SCMI with this.

Tom

[Tom Trees]

So Been looking at some other machines as I said, and also been trying to find out if the Centauro's are the same non shouldered bore as mine.
Managed to find a manual for the CO 600, and a bunch of the other ones
http://www.targetmanufacturing.co.uk/wp-content/uploads/Centauro-CO600-700-800-900-Bandsaw-Manual-Parts-List.pdf

Sorry, couldn't copy a picture from PDF, so you would have to go to page 35 to see both wheels.
At least I know it's only one spacer, which I'm guessing wouldn't be there if it were machined bores for both shaft and bearing.
I'll be studying this manual again just to ponder some differences.

Now to find out what Centauro use for this spacer, rubber, steel, cast?
Hopefully one of you creekers might have that knowledge?

Thanks
Tom

[Tom Trees]

Back again, and think I'm getting closer to finding out what materials I need for the job.
This is a Centauro CO 800 machine, as seen in this thread which I've stumbled on.
https://www.owwm.org/viewtopic.php?f=1&t=180094&start=15

So I can see that the shaft isn't proud like on my machine.

471402

A shot of the carriage assembly
471404

And a shot of the spacer, which I only see one of, looks like mild steel will do the trick.
Hedging my bets on the Centauro having a non shouldered bore,
so I'm gonna guess this will work if I find some suitable pipe and turn it like Jack on my wood lathe.

471405

Regarding the shaft protruding from the wheel. I can try fix that with something later, and see how a spacer works.
Cheers

Tom

[Jerry Bruette]

I don't think the bearing spacer is causing the wheel to wobble.

In your second picture I can see a groove worn into the shaft. That's probably the source of your wobble and the shaft should be replaced. I also notice a split/spring pin in the shaft next to the snap ring, not sure what it's for though.

The spacers between the bearings are typically made from steel and could be a piece of pipe of the proper diameter. It should touch only the inner ring of the bearings and be the proper length between the bearings while they are properly located in the hub by the snap rings.

I don't believe the big washer on the outside of the wheel should capture both rings of the bearing. I think it should touch the inner ring and have a small gap all around so the wheel can turn, if you capture both bearing rings the wheel can't turn.

[Mitch schiffer]

I don't think the bearing spacer is causing the wheel to wobble.

In your second picture I can see a groove worn into the shaft. That's probably the source of your wobble and the shaft should be replaced. I also notice a split/spring pin in the shaft next to the snap ring, not sure what it's for though.

The spacers between the bearings are typically made from steel and could be a piece of pipe of the proper diameter. It should touch only the inner ring of the bearings and be the proper length between the bearings while they are properly located in the hub by the snap rings.

I don't believe the big washer on the outside of the wheel should capture both rings of the bearing. I think it should touch the inner ring and have a small gap all around so the wheel can turn, if you capture both bearing rings the wheel can't turn.

I agree. I find it hard to believe the spacer or the washer size has much of a role if any in your wobble issue. Those bearings are shot. Get your self some new sealed bearings, reassemble, and the pin point any further problem using a dial indicator.

[Tom Trees]

Hi folks
Just to clarify the shaft seems in good nick, and it's only a patina that the camera is picking up on.
471421
Was looking for suitable pipe, but all I have here is stuff which is too large internally :(
That's mushrooming on the ends, and the stuff ain't that thick.
471422471423

Measured the width of the orange spacer, and it has around a half mm of variance, but I did not check it with a tram on the drill to see if it were square.
Didn't try and measure the slot for the snap ring to see if there was much slop either.
There could be more slop than it seems at first, and I've also got the old bearings so I can sneak up on the right fit.

So with only one chunk of rusty steel hefty enough for machining, I figured I'd check the lower wheel on my saw,
as there would not be much point in making something for one wheel, if the other was needing the same treatment.
Glad to note that the washer is indeed making contact with the inner race, and held fast, so I figure I might as well have a bash at it.

I'd love to know how tight of a fit that spacer is on the upper shaft on the Centauro machines, hopefully someone can help me with that.
The photo I linked looked a slip fit to me, so guess I'll go with that, should someone say not to.


I don't think there is much point in putting a clock on the wheels as things are, since it's free to move about yet.
The shavings from the plane iron scraper are consistent though, so I reckon it's likely good enough in that regards.
471424

All the best
Tom

[Tom Trees]

Hello folks, was hoping to get onto the OWWM, but still waiting for a confirmation e mail.
I was wanting to question that guy why the spacer is so narrow on the Centauro machine, and found him since on youtube.
Not sure if he's active, hoping he can answer me about the bore in those wheels.

Surprised that no-one has an answer for me here, nor can I find much online elsewhere, says a lot about those saws I suppose.
Seems I'm good to go ahead and start working on making one, and will see how the spacer works out.

Tom

[Jerry Bruette]

Hello folks, was hoping to get onto the OWWM, but still waiting for a confirmation e mail.
I was wanting to question that guy why the spacer is so narrow on the Centauro machine, and found him since on youtube.
Not sure if he's active, hoping he can answer me about the bore in those wheels.

Surprised that no-one has an answer for me here, nor can I find much online elsewhere, says a lot about those saws I suppose.
Seems I'm good to go ahead and start working on making one, and will see how the spacer works out.

Tom

Not sure what you mean by "narrow". If it's the wall thickness, it needs to only touch the inner ring of the bearing. If you mean the length, it only needs to fill the space between the two bearings while they're each located against the snap rings that hold them in the bore of the hub.

I still think there's a groove worn in the shaft on the end by the roll pin.

[Tom Trees]

Hi again, aye I should have worded that better, sorry for confusion.
I suppose I should have said that the Centauro spacer isn't as tall, i.e bearing to bearing, and wondering if I'm missing something,
as seemingly on over 90% of other Italian saws. have a small washer.

Looking closer at the pics of the Centauro with the washer off, one can see that it appears to capture the hub,
Without knowing if the other picture of the wheel is properly seated on the shaft, if it is, then maybe those washers are not just washers and have some raised profile.
to butt up against the inner race.

Just trying to see if I can make it more solid should the Centauro's new SCM's ,SCMi 'sbe an improvement, which could factor in a lot of reasons,
as they're the only ones to go this route.
Some other designs like on the Hema's or Multico's are used, but everything else, about 20 brands/lines of Italian saws having a simple washer which presses on the inner race.



Thanks
Tom

[Tom Trees]

Just got logged in to OWWM, seems the dude with the Centauro hasn't been online since October.
Seemingly a lot more Centauro owners here.
Having actually reading the post, and learning that there is actually a plastic spacer in the bottom wheel,
which sounds like a good fit, since the guy had to drift and crack it, and the other spacer which I linked mentions the spacer survived this time round.
which looks like metal to me.

Another forum member Bob made him up another, can't find much of his postings, hoping he might answer.
Might as well post there too.

Have spent at least a day looking around with no answers.

Hopefully someone would be able to tell me if those wheels are the same as the rest of the Italian machines. (non shouldered bore)

Hopefully someone with an Italian machine which might have something different than the plastic insert my machine has
can mention something.
i.e a thicker plastic insert which would have more contact with the inner race, or even made from something else.

Thanks
Tom