Centauro 400 SSP Bandsaw (does anyone have a manual!)

[sams93]

Really cool to see your updates @Ttrees!

My 16mm bearing arrived yesterday, I think I have absolutely everything ready now to start putting it back together. I didn’t have much time in the shed today but did manage to make a circular wooden drift for pressing the bearing in. I don’t have a press so I’m intending to use a 10mm bolt with a wooden block bracing one side, and either a spanner or maybe my impact gun to drive it home. Will be similar to what is photographed.

Of course I’d rather a) use a metal drift and b) have a press. But this project was about seeing if I could fix it with what I have.

@Ttrees did you find the fit was tight enough with just your shimming alone? I’m intending to use retaining compound as well

 

[Ttrees]

@Ttrees did you find the fit was tight enough with just your shimming alone? I’m intending to use retaining compound as well

That's basically the idea in sinking the bearing, as it's practically un-measurable.
Still very tight of course, though yet unsure how accurate, it could be a country mile out.

Been pondering on how to do a better bodge, would be lovely to have some 30mm bar for this,
and have seen what the runout was like, using just a pair of them stuffed beyond the journals,
and using that if accurate.
Also would be nice to have some tool which could be expanded to save removal of material
outside the cir-clips, along the lines of a taperlock pulley.

Not sure if you're intending to make a sleeve with that shim stock,
or are intending to do otherwise.
This stainless seems really nice stuff to work, it's really durable,
and becomes substantially more rigid with proper shaping, i.e sandwiched with force between bearing and bore.
I reckon if that's what you were thinking, the sleeve would stay put whilst you insert the bearing.

Before that, I was guessing it would sink with the bearing, but not so, and quite the opposite.
That could be down to many things.
My boring tool could be tapered, or it could be down to the way the tool works.
There may have been that profile existent already,
or likely other things I've not considered.

Not sure if any of that helps.
It'll be interesting to see if I can get away with it, in hindsight it would have been a darn good
idea to have checked the un-damaged bore, but as said, I wasn't aware it was possible to draw them up through, and that was a silly.
Even if I have failed with this bandwheel bore repair, perhaps
someone might get some insight into doing things better...
if I don't have to do that meself.

Lots of things to procrastinate about if you ask me.
Remember, upon opening ANY glue container, you instantly loose 20% of brain capacity!
I'm thick enough without the help.

All the best

Tom

 

[sams93]

Here is my creation to press the bearing in. I have domed the middle of the underside of the wooden drift in order to be sure there is no force applied to the inner race when pressing. Currently it has an M8 bolt but I’ll use an M10.

I’m intending to freeze the bearings before doing it, not sure how much difference it will make realistically.

Now am just waiting on the 2mm shim washer (replaces the original 6mm one) to arrive which will sit between the bearings which are now 12mm and 16mm (replaces the original 12mm and 12mm bearings). All apparent from the diagrams below.

Hoping that they will be here tomorrow…

 

[Ttrees]

Hello again
Not got around to testing yet, but just wanted to mention the fact you have no
tires on the machine, which lends itself a lot better to some sort of jiggery.
Guessing you're also going taking the chance that within the bore will be accurate.
If I was going to do this again, and had removable tires...
I might think about seeing if it were possible to install the wheel very carefully without the spacer
and see if you could rig up some sort of tramming device, to either detect light by eye, check gap with feelers, or possibly rigging up a marker from the top somewhere might work well either.

Doing this without a blade installed I might add.
All the best
Tom

 

[Ttrees]

Hello again, been doing some tests since, and have only noticed now that I'll have to dress
the face of the wheels in order to align them.
I'm getting the same readings regarding both sides of the wheel.

I had the impression all wheels were machined, due to some toolmarks on my wheels,
but that work isn't even ballpark at best, and obviously as little work as possible just to clean off the slag.
I'd guess this piccy (which I hopefully can borrow for other forums?)
is most likely accurate, as is questionably the same as with @deema and @Sideways S45 thread.

https://www.ukworkshop.co.uk/threads/scm-minimax-s45-bandsaw-teardown-overhaul.135069/Looks to be front and back on this particular Centauro machine, but it's a pure guess.
Perhaps other machines are too, and simply machined very nicely, perhaps that's anyone's guess?
as they all appear to have some work done.

Quite noticeable on your machine though.

Still noticed the same high spots on the face of the wheel.
Maximum discrepancy, a thin Shinwa rule.

Which encouraged me to check the lower wheel, which was at most half that I guess.
Didn't take the feelers out or anything, as trying to measure could likely give false readings,
well on the upper wheel anyway.

So spent some time looking at some, mostly other Italian machines.
Doesn't seem to be many other wheels like those above.

Kinda makes one question how the factories align the wheels in the first place,
or infact if they're not even trying atall?

Not read of machines with truly flat tires needing to get broken in,
Could it be as to why this being unheard of, because Centauro references from the groove in the wheel on some wheels?
I'm guessing they might, simply because I don't see reference anywhere else on the wheels,
and a variable width wheel which isn't vulcanized and dressed in house would likely highlight this
due to the crisp edge of the wheel acting as the crown,
i.e the blade following it, and causing "fore and aft"

Not going to trust my lines yet.

Haven't trammed the OD of the wheels yet, not powered the machine up either,
but no flutter between guides is promising.
Seems I might have to flip wheel over again "tails side" to check the wheel and not the tire,
since there's a little of the wheel to check things,
though I'm not convinced that might be accurate either, seeing as that part of the wheel might
never get used by most folks.

Hopefully I can put this in a separate post, should things have gone well with the bore work,

Tom

 

[Ttrees]

Just to report back regarding concentricity, seems things went very well, which I've documented more thoroughly in video format for the skeptical.
I tested the face/lip/edge of this side of the wheel also, and noted less of a discrepancy than the lower wheel.
Seems I'm good to go and belt ahead and dress those wheels.

I did have a think about making a boss for the upper wheel, but reckon it might be a wild goose chase yet, as the lower wheel is much the same setup.
Perhaps laterz if it proves to be troublesome, which I doubt, seeing as there are examples of similar
machines to mine running very well indeed, which TBH I haven't been able to see, should there be some notable differences, which I can explain elsewhere, not as to clog this thread.

Not sure I've anything to add, but mention I'll be trying to make a video in more detail compiling all the footage in something tolerable, should I be able to with my setup.

Good luck again
Tom

 

[sams93]

So today was the day for re-fitting the bearings.

I had put the new ones in the freezer overnight to hopefully make fitting them a tiny bit easier, although I doubt it made much if any difference. I had cleaned and degreased the hub ready for fitting before I started.

Started off by fitting the replacement 12mm bearing (KOYO 6004) into the 'good' side of the hub. I used some Loctite 638 and my homemade 'bearing pressing contraption', which worked surprisingly well! I pressed that bearing in to the point where I could just about fit the 42mm internal circlip in place.

Then came the side of the hub which needed the fix. I had opted to use a 16mm bearing (KOYO 63004) instead of the original 12mm bearing (this was to allow me to use 4mm of the 'good' hub area to make sure it was seated properly and centrally). Originally there was a 6mm spacer between the bearings - I replaced this with a 2mm and 0.25mm shim washer to allow for the 16mm bearing.

I applied some loctite, and then pressed the 16mm bearing into the hub, along with some vertically aligned pieces of 0.15mm feeler gauge to shim the area where the hub was worn until it was tight with the shim washers. It seated really nicely into the hub and I was quite pleased really with how it went. I then had to trim the vertically inserted shims to make them flush with the bearing, such that I could insert the circlip. I then went to actually insert the circlip.... which is when it sprang off over my shoulder, and landed somewhere over the wall in my garden into some bushes . I tried to search for it but failed, I have ordered a replacement anyhow.

Lastly I pressed the spindle into the now mounted bearings.

I left it for a little bit before coming back to re-examine my work. Gave it a good spin up and crossed my fingers that things were central - and as far as I could tell they were!

So thats where we are at currently.

Next on the agenda is to fit the replacement circlip when it arrives, and put the wheel back onto the machine to give it a spin and check for parallel etc.

 

[Ttrees]

@SamS
I hope it's a success, and I guess reversible even if it ain't.

Say, that's a nice beam you've got there!

I wonder if you might be thinking of seeing how consistent those wheels are for alignment purposes?

I'm wondering if the face is accurate........ or possibly even intentionally not the case!,
as the face or lip of your wheel, looks to have had plenty of attention compared to my saw.

Which I paid some attention to yesterday.

All the best
Tom

 

[sams93]

@SamS
I hope it's a success, and I guess reversible even if it ain't.

Say, that's a nice beam you've got there!View attachment 159836

I wonder if you might be thinking of seeing how consistent those wheels are for alignment purposes?

I'm wondering if the face is accurate........ or possibly even intentionally not the case!,
as the face or lip of your wheel, looks to have had plenty of attention compared to my saw.

View attachment 159835

Which I paid some attention to yesterday.
View attachment 159837

All the best
Tom

I can check on the weekend when I will hopefully be able to mount the wheel back onto the saw. You want me to check if the upper wheel aligns so that it is true with the lower wheel is that right?

 

[Ttrees]

Both the tramming test, or this beam test would show variance of the wheel.
I was under the impression that it would show up wear of the bore
causing wheel wobble, as my saw was being very noisy, not cutting well atall,
and eventually spotting a temperamental loose bearing.

My wheel had 0.5mm variance of the front edge, well at least
I'm confident this is the case, speculation yet however.

You could do either, but just to clarify that I mean it's something necessary if wanting
to try aligning the wheels, unless you can come up with some clever way to use the
groove in the wheel either for alignment of the bottom wheel & motor to the upper one.
It's not a done thing BTW.

Here goes whatever you wanna call this pre-alignment test or.. wheel variance test?

Put four bits of tape on the wheel, 12, 3, 6, and 9 o'clock.

Find/prep an accurate piece of timber thick enough that the beam resting on it
will clear the chassis "waist" in between wheels.
It needs to be the right length to fit on the RHS of the machine

Make plug with PEN for the end cap of the beam.

Put a short bit tape down where the beam rests upright, now choose a few times on the clock
and see if it lands on that spot or line on the tape,
or if you get variables.
If you get a variable line you cannot trust the face of the wheel for alignment,
like these guys

See the timber is the right length to fit into the chassis on the RHS,
thick enough so the aluminium beam will clear the chassis,
and wide enough to skew the beam to draw a line.

Timber bumped up against the chassis makes life easier.

I ended up getting the exact same reading as before, so you'll have to wait until I do this test later
after filing the face of my upper wheel.
If it proves successful, then I'll do the bottom one also and then show this for real again.

One could speculate things might not be so straight forward, but hopefully any little niggles I've been looking for, but haven't found may get sorted.
Still haven't test run it though, and that's when things really become apparent.
If successful, then balancing might get ruled out, kept in mind for the very last thing on the list,
but not before tire dressing should it need a lick,
and tire edge dressing which is something I've been trying to research for a long time,
regarding saws specifically with true flat tires.
(fore and aft movement, beam tension of stout blades, and a boat load of other stuff)

I'll hopefully get back to you soon, and finish up working on the saw.
There's not much left to do, and been stuck waiting for the wheel to get done, as
my motor is somewhat Centaurolized, (adjustable concerning alignment)
for the flange mounted motor on my machine, so a differing approach to the foot mounted one below on the Minimax, but with the same adjustability to suit the upper wheel,
as there's no ability to skew it like the lower one.

Cheerio

Tom

 

[Morty]

Not sure if this Centauro SP series manual will be of use as you are so far down the road with your refurb.

 

[Ttrees]

Glad to see the one line instead of two, what were 4mm(ish) apart.
Done the lower wheel also, about 0.2mm discrepancy now on both wheels.
Time to draw another upper wheel line, and adjust motor and lower wheel to suit.

Cheerio
Tom

 

[sams93]

So the repaired wheel is mounted and working - seems to run fine and has no wobble. There is much less vibration in the saw now, it's a world apart from where I started and there's much less movement in the blade. The blade I have has a small kink in and seems to be blunt so I haven't been able to give it a fair test. I still feel there is some progress to be made, however, so the next jobs are:

• Replace the top wheel tyre which is beyond serviceable repair with a new tyre (annoyingly it cost half what the whole saw cost!)
• I have cleaned up the table, there was some glue and general rust on it, now all cleaned and polished, finished with a couple of coats of Liberion machine wax stuff. It's looking good and I will re-mount it on Sunday. I made a new table insert from an offcut of oak, it's far from a 'zero clearance' insert as the slot I've made for the blade is about 5mm wide, I might end up re-making that at some point.
• I had intended to replace the bottom guide (which is of the block type with a rear bearing) with the Axminster replacement I have, however I discovered that the axi one won't fit without me making a hole in the lower body of the saw (It would protrude too far rearwards otherwise and hit the body), which seems a shame so that option is out for the moment. I have decided for now to just sort out the original lower guides (I'm actually not sure if it is original as it is cast aluminum yet the rest of the saw is entirely steel + iron, but the mounting plate seems original and looks to be made for the guide - photo attached). I made some new blocks for it out of some iroko that I had to hand soaked in some Liberion wax - I will get hold of some lignum vitae and make some from that if this all works out. Replaced the 608Z bearing which acts as a thrust bearing to support the rear of the blade.
• Dissasembled, cleaned and lubricated the top guides (GL456 type). They were caked in a solid grease which was doing nothing. The rear thrust bearing wouldn't budge at all but after dissolving all the grease with some WD40 I eventually got it moving. The rear thrust bearing is missing it's cover, and there are grooves in it from where it had seized presumably. This resulted in quite a lot of sparking in use. I can get a replacement for £50 but I will try and do what I can with this one first. I ground the face flat, removing the original ridge which is where the grooves were so that it is now flat. Then I slightly rounded the edges and polished it up.
• I also purchased two new blades from Ian at TuffSaws, which hopefully will be here by the weekend as well.

All being well, all these parts will be installed on Sunday, and I'm hoping that will get me nearly finished on this!

 

[Ttrees]

Glad to see it seemingly sorted, fair play.
Worth noting again the flat tire profile for Centauro might not be your preference,

PS that upper tire is the worst state I've ever seen, very risky running with I'd think,
perhaps you've not seen the YT's with that happening,

and not to mention if using thinner gauge blades, (thinner kerf)
might not be so forgiving on them compared.

What's the lower tire like, I would think it needs replacing also.
Link way back in this thread for cheap solution, though I've not seen anyone try.
Might it be worth ebaying to see if some 400mm tires are available cheap.

Tom

 

[sams93]

Glad to see it seemingly sorted, fair play.
Worth noting again the flat tire profile for Centauro might not be your preference,

PS that upper tire is the worst state I've ever seen, very risky running with I'd think,
perhaps you've not seen the YT's with that happening,

and not to mention if using thinner gauge blades, (thinner kerf)
might not be so forgiving on them compared.

What's the lower tire like, I would think it needs replacing also.
Link way back in this thread for cheap solution, though I've not seen anyone try.
Might it be worth ebaying to see if some 400mm tires are available cheap.

Tom

What is the issue with flat tyre profile? Is there a reason not to replace the original tyres with the manufacturer replacement parts?

The Centauro takes a tyre with a male rubber ridge in the middle of it which fits into a recessed groove machined into the wheel, so I wasn't keen on replacing it with just a random flat urethane tyre.

Lower tyre is surprisingly OK, other than superficial marks it seems fine - i'll try and find a photo.

 

[Ttrees]

It depends on how much circle/curve cutting you are planning.
I believe the groove isn't in the middle of the wheels on all those saws I've seen, of which aren't older ones with vulcanized tires, and couldn't advise if it were possible to swap the tire back to front
to account for wear.
The tires are molded with the tongue offset to match...
Could swap the wheel back to front I suppose, should lower wheel belt alignment not be of issue.

That's your call on how much wear you're happy with.
My older vulcanized tires are soft now, (not sure how much different from new)
and wouldn't appreciate running narrow blades.

Just sayin as you didn't sound keen on the cost of them, so seemingly you're not having business
values, i.e treated as a consumable, and no time to be dressing tires.

Tom

 

[sams93]

I would say the work I currently do on my bandsaw is 80% straight cutting 20% curved cutting.

As you say, the groove is not in the middle it is slightly offset. I have no intention of swapping it back to front, there just is not much wear on the tyre so it does not seem neccersary. I might take that comment back later if I have to replace that tyre as well.

Yes I am keen to do the refurbishment as cheaply as possible, partly because I cannot actually fit the machine into my shed at the moment, so likely it will sit in my parents garage for a couple of years before I am able to get a workshop big enouth for it!

@Ttrees you talk a lot about dressing the tires, but I haven't managed to find much elsewhere on this topic, in fact even when I try to look up about it all that comes up is you talking about it on other forums or youtube . Is this a common practice or is it quite a niche thing?

 

[Ttrees]

You'll not likely not find talk about it regarding newer Centauro's.
These machines are built for industry, so no sending wheels off to Italy like some of their competitors.

You might find info by searching for vulcanized real rubber tires, or cork/rubber composites.

Might I add the longevity is mentioned to be lesser than real rubber, and generally the thing to do is replace both, if the upper tire is perished?
You'll probably find evidence of replacing only one tire or tyre, and something bad happening, but you'd likely find success stories also.

Tom

 

[Ttrees]

Hello again
Since got my machine running pretty smooth, but still having issues with beam tension.
Seems I was indeed, chasing a red herring regarding having flat tires on a bandsaw....
I have came to the conclusion that no machine actually has.

Mythbusting using a really cheesy gauge
It's a Centauro tire, for a CO600 from S&S, looks like it'd be quite a strech to get it on.

I'd not thought of measuring this before, as myself and I guess seemingly everyone else, would presume these tires were flat from a glance.
Reading the Centauro manual again suggested this,

And noting the ACM promo video on YT, would suggest the same as their neighbors in Modena that this is the case.
I was thinking it maybe have been a typo, as on elsewhere.
Not sure if you'd call that the bottom line or not, but seems like I've put more effort into all that than I've seen elsewhere.
Not to say others haven't ventured there, i.e Bob Vaughan on another forum,
but without much other than a passing comment, not good enough for me to believe.

I've documented all that and more on video, but the linux computers crashing uploading youtubes, might see if I can get the last video to load.
I can't even edit my videos to mention this, arragh!

So... apologies for my continuation regarding that dis-information.
Well, I will be doing one or two last things before being absolutely 100% sure that flat tires can't work, having somewhat visited all this before, since, and in-between,
I suppose those things will have to be checked again since I've done a fair amount of work
and the variables are eliminated since.
Hopefully it'll be as simple as creating that profile.
All the best, and good luck to ye.
Tom

 

[sams93]

Haven't posted an update on this in a while but have been busy working on it.

Reinstalled everything and re-mounted the newly cleaned and polished table.

New tyre fitted to the top wheel to replace the horribly worn out one.

Got 2 blades from Ian at Tuffsaws

• 3/4" - Fastcut (Basically 3TPI)
• 1/2" - SuperTuff Premium 6TPI

Ran the saw up with the guides loosened off, working like a dream! Still some very slight residual vibrations, but completely within the realm of reasonable for the saw of this size. I do wonder if replacing the worn lower tyre as well would be sensible, i'm just too tight pocketed to want to spend another £40 on a tyre!

I set the guides and managed to saw up a variety of test pieces. I thought I had enough tension on the blade (actually I was worried I had too much!) but the blade did spend more time than I would have liked riding the thrust bearing, to the point where the thrust bearing body was actually warm to touch. I think I just need to put more tension on but I got a bit scared! Maybe I should buy a tension indicator. I'm not familiar with saws of this size so it seemed a lot of tension to me!

I'd like to be able to do a bit of resawing on the saw, so I had a go at sawing an oak log about 28cm thick with the fastcut blade which I was delighted with, even managed to cut a very thin veneer about 2mm thick and the finish was good and the thickness even.

The lower guides on my saw (i'll try and get a picture) seem pretty undersized and flimsy compared to the GL upper guides. They are small wooden block guides with a rear bearing, but the wooden blocks are tiny, like 7mm x 5mm - even my tiny hobby 3 wheel CBS355 has more substantial guides. I do have a set of the axminster professional upgrade guides, which I had intended to fit, however there is not enough room behind the blade for the axi guides and so to fit them I would have to make cutouts in the steel frame of the saw which seems a shame.

I noticed that the upper wheel had a light coating of dust from the blade so I think it might be sensible for me to add a brush somewhere.

I'm thinking the next steps are going to be:

1. Suck it up and buy a new tyre for the lower wheel.
2. Find a way to install a beefier lower guide system (I've asked someone with the same saw as mine to send a photo of his lower guides so I can see what mine should be).
3. Make or purchase a blade tension gauge.
4. Possibly I should change the motor drive V belt (I know some people find that vibrations come from a worn drive belt, mine seems OK but it makes sense to change it as they arent expensive.