Centauro 600

[Brian Holcombe]

Ask a question about CT Blades

Personally I use the 1.3TPI and I have similar experiences to Tom. I recently ordered a pair of blades from CT Saw in CT and they laughed at the order history since the last order was placed 4 years ago. I thought the blade had gotten dull but it was in need of slight adjustment, and it's still cutting. So I have two blades hanging on the wall and have one that's been on the machine for 4 years of daily use.

The teeth hang off the front edge of the wheel, the wheels are flat. There needs to be a fair amount of tension on the blade, more than the standard blades.

[STUART Robertson]

Thanks Brian 👍

[STUART Robertson]

Interested in others preferred CT blades and experiences.
What was the nature of that adjustment Brian?
I also need to make large dimension crosscuts at times.

[STUART Robertson]

Have recently found Van Huskey's
treatise on bandsaw blades from 2010.
Very good.

[Mark e Kessler]

Assuming everything else is adjusted correctly (I know that doesn't help...lol) I adjust my fence to compensate for drift if any.

[STUART Robertson]

Thanks Mark,
Used to do that but now if everything is adjusted correctly then shifting the fence is going to put the alignment with the mitre slot out.As I understand it now, it seems like micro adjustments with the tracking are the way to go.If the work is pulling away from the fence,then the blade needs to track a touch further back on the wheel,if binding on the fence,a touch forward...
So many opinions out there on tracking my head hurts🙄😬
And then as you say everything else has to be right too,can be a bit of a torturous process of elimination.

[STUART Robertson]

Mark,
Hope you're not sitting a chair all day...waiting to die...unless age has caught up and wearied you.You must have a wealth of information to share.

[STUART Robertson]

Andrew Whicker -
I have managed to use the search function and have now read your posts.My saw has the original guide setup and not the mess you started with.And the tension guage is still mostly functional. Definitely similar levels of frustration and where to next when I viewed your tube vids.
Haven't seen any later posts but wondering how you've got on and is the saw now functional for you.

[Tom Trees]

.


I did put a dial gauge on both wheels and each seemed to have a variance of about 5/100 mm,given the vagaries of a cast iron surface.
But no comparison to each other.
It would seem that to be relevant any variation needs to be measured at the horizontal mid line.
Given the relatively small diameters of the shafts this feels difficult to achieve in a meaningful way in a woodshop.
If I set the saw level and then shot a vertical laser line I'd possibly pick up some variation?

Thinking about this, you could do that with the laser also if you wished, as mentioned mounted onto the wheel shaft/against bearing race...
but you would need strong clear plastic in place of the table.
That way you could see the difference between the pen lines drawn thereafter, and adjust accordingly.
Seems an extra step/thing needed to me, and still ignoring the motor, so that might mean buying a longer belt(s)
and crossing ones fingers.

It seems that might be what General were doing in this video, though we only get to see a mere glimpse of things really.

Screenshot-2022-5-26 How It's Made Band Saws.jpg

https://i.postimg.cc/LXkxLJ2z/Screen...-Band-Saws.png
Screenshot-2022-5-26 How It's Made Band Saws(1).jpg
https://i.postimg.cc/Hk74brtV/Screen...and-Saws-1.png


Here's another link to some approaches, much the same without considering the motor,
but in this case, I doubt the wheels may have been as nicely machined as the General's made in Canada, that's just a guess though.
https://forum.canadianwoodworking.co...8-bandsaw-woes

That's for one who would like to chase their tail, as I did for too long.
Having a pen on the end of a beam is far more telling, as it shows whether a wheel can be trusted or not, in the first place.
Though if adamant to instead try the straight edges with the plumb bob lines, or to try spotting something else what might not be right,
I can mention these four magnetic blocks (could be taped on) were the only way I found to get on with making working with plumb lines,s
having both top and bottom stabilizing them, the same as with the third for checking upper wheel protrusion, having both wheel retaining bolt heads to use instead.
I played around with that, whist also speculating & dressing tire edge crispness, (old vulcanized ones with some damage) so you can imagine quite a bit of fuss to line up the
edge of the rubber to have both edges in plane, and it amounted to nothing.

SAM_4964.jpg
https://i.postimg.cc/vBs3Kqkf/SAM-4964.jpg

SAM_4977.jpg
https://i.postimg.cc/vHk7j26T/SAM-4977.jpg

Tire edge dressing, (not under power)
Screenshot from SAM_6242.MP4 - 1.jpg
https://i.postimg.cc/XYNZswsq/Screen...6242-MP4-1.png

That's if you wanted to chase red herrings.

Tom

[STUART Robertson]

Thanks Tom,
Think if I set the saw up so that both wheels are plumb then set a laser line at 90 degrees to that plane then measure back to the wheels at the horizontal mid line
the laser will hit the "ruler" whenever it intersects the laser.
Not the micro measure I would like
But should give some idea maybe.
Given that the blade has very little evident wander at the apex of the top wheel maybe they are not too far out.(?)
It seems to me the the major consequence of having wheels in east/west,left/right misalignment is erosion or excess wear on the crown of the tyre more than it causing blade wander or drift.(?)

[Tom Trees]

Thanks Tom,
Think if I set the saw up so that both wheels are plumb then set a laser line at 90 degrees to that plane then measure back to the wheels at the horizontal mid line
the laser will hit the "ruler" whenever it intersects the laser.
Not the micro measure I would like
But should give some idea maybe.
Given that the blade has very little evident wander at the apex of the top wheel maybe they are not too far out.(?)
It seems to me the the major consequence of having wheels in east/west,left/right misalignment is erosion or excess wear on the crown of the tyre more than it causing blade wander or drift.(?)

I wasn't convinced at all, of exactly the method described,(on the ozzy forum), and can thoroughly recommend taking footage of your setup,
as it showed up things which obviously weren't clear , like the bandsaw being level for instance.

Compression of the set is the most notable thing experienced, and excessive rubbing into the thrust guide/bogging down for no good reason,
mostly fore and aft blade walking.
I've got quite a few differing types of blades which I need to reset sometime, which I'm guessing is what your most notable issues are.

You could put it this way... if that method worked, they'd be making machines with adjustable motors.

Could also mention I didn't likely do my upper wheel bore any favours by assuming the faced lips/edges of the wheels were trustworthy to start with.
SAM_7943.jpg
https://i.postimg.cc/Vv7sFzJg/SAM-7943.jpg

All the best
Tom

[STUART Robertson]

Surely the adjustable motor,if I understand that correctly,is a minor thing as long as the pulleys are reasonably well aligned,unless they have moved on the keyway, and the belts under suitable tension.
I can see that if significantly misaligned with excessive tension that may cause biased loading on the band wheel bearings/shaft.
Haven't seen or read the Australian forum.

[STUART Robertson]

Interesting thread starting with Bill Space 09/2018

[Kevin Jenness]

It's easy to make a simple thing seem complicated. Bandsaws are about the most basic machines one can find. I've used many through the years from 14" and 20" Deltas and 16"-20" Aggazanis up to a 36" Crescent and never had significant problems that couldn't be cured with a new blade and tracking adjustments. You've put on new bearings and tires. I really doubt a minor misalignment between the upper and lower wheels is fatal but if you want to get the best measurement of that pull off the tires and measure from a vertical plane to the grooves, or use the edge of the tires- you can see easily enough whether the tire edge is spinning in a plane without significant runout. Put a dial indicator on the tire rims to see if they need dressing. If the tires are flat run the teeth off the front of the wheel, if crowned run the blade centered on the crown. Put a new blade on- if it doesn't run true try another one, making sure the welds are not causing a problem. There are only a few factors in play, run them down in order.

[STUART Robertson]

Thanks Kevin,
Agree,I like to keep it simple where possible.
And agree with starting with simple cures first.
I thought I'd done that and thought it didn't work...which sowed seeds of doubt for further issues.
One being was I sold the correct replacement tyres...now trying to confirm that or otherwise.
And does it matter,flat or crowned.Do I simply work with what I've got.
Manual says hang teeth off tyre,suggesting flat tyres...but mine are crowned...etc, then all differing opinions re blade placement on those tyres.
So yes,trying to identify the starting point and my own errors.
Thanks again.