Bandsaw blade tracking

[Groggy]

I've read this thread to this point and have come to the conklusion you murricans have a combination of cabin fever and a slow news day.

In my mind, the blade naturally tries to climb onto the ridge on the wheel through the drag effect caused by the added resistance. If the ridges on each wheel are not aligned with each other, the blade is struggling to find equilibrium.

It may not be right, it may even be a crackpot theory, but it will hopefully keep an otherwise entertaining thread alive.

Groggy (who's hoping for an early thaw in the USofA)

[Groggy]

Oh, and one more thang, doesn't a spinning object naturally try to bring itself to vertical, the higher the speed the greater the force?

dunno why, I just wanna cause a ruckus tonight...

[Groggy]

g'day Noons, haven't read your voice for a while. Hope all is well at the new abode.

cheers,

Greg

[Noons]

dunno, Groggy. When my head spins, I feel like lying down...

[Edwin Pawlowski]

What railroad?

[Noons]

Narh, still waiting for the builders... Bastahds!

[RPRESHONG]

I find putting one foot on the floor stops the spin.

[Noons]

Hmmm... I usually have both of them on the floor to start with.

:D

[brocpuffs]

After snipping lots of wind, I add:

How about angled wheels? When ya adjust so the blade will ride in the center, you adjust the tilt of the top wheel from the vertical plane (trying to SOUND) like an engineer here).

Wottehell, this will have some effect, too. Real effect, not speculation

James [e-mail]\

[Larry Jaques]

On Thu, 12 Feb 2004 10:50:09 GMT, "Groggy" brought forth from the murky depths:

No, it simply resists turning due to gyroscopic effects.

And you said it was the 'Murricans who had cabin fever?

[Michael Daly]

I'll ignore it.

For blades of different size - yes. For blades of the same size and make - negligible.

Either the alignment isn't bad (even though you haven't changed anything since you bought it) or the amount of crown + the tension + other stuff is forcing your blade into some stressful alignment.

I've done a bit of experimenting with the amount of alignment (easy, since the one I have came 1/4" out of coplanar!) and you can make it work while slightly out of alignment. But if properly aligned, you get good tracking and less blade vibration/wander/drift/etc.

Maybe you're not fussy about the quality of the cut.

Mike

[Michael Daly]

You tension the blade and the wheels tilt in. You tilt the top wheel out to realign. This makes them parallel again at the expense of a slight change away from coplanar. As I said in another message, you can get away with a _slight_ misalignment.

I once tried adjusting the saw so that it's coplanar even under tension. This is an iterative approach that means adjust, tension, check, detension, readjust, tension, check, detension, readjust, tension, check... until the alignment is "perfect" under tension. It didn't work significantly better than the conventional alignment but was a _lot_ more work and the adjustments were different for each blade. The reason is that all that fiddling doesn't make a lot of change in the actual alignment.

Coplanar - the easy way to get good alignment. Non-coplanar - maybe it'll work if you're lucky and/or you don't care much about the resulting cutting quality.

Mike

[Rick Chamberlain]

Believe me, you can get away with gross misalignment if you have a forgiving blade and a good crown on the tires.

While this might help you sleep better at night, you're spending way too much time on this. The bottom line is that if the blade tracks well while under tension and torsional loads, you got a winner.

It's kinda like tuning up a 65 Mustang. You throw out the book and go by feel.

And while Duginske is a good read, he puts too much emphasis on coplanar wheels. He should have spent time teaching the masses how to crown a tire.

Pretty broad brush there Mikey. Do you have scientific evidence to prove this? Seems to me my non coplanar saw cuts just fine, thank you. And, I *do* care about cutting quality and blade life.

Just remember - it's wood, not platinum.

[Unisaw A100]

Thanks Rick. I was this close to slitting my wrists onna 'count of I wasn't getting glue ready edges from my band saw.

UA100

[Groggy]

In which case Larry, trying to turn within two dfferent planes would not be a good thing, equilibrium wise.

Maybe we should all agree that Woody is right and go back to bed. I need to tend to shop dog's nose anyway...

Greg

[Unisaw A100]

A least one of the signs of the impending apocalypse.

Hey! Compressed air will fix that puppy up.

UA100

[Groggy]

Trust me, *more* compressed air is the _last_ thing my dog needs...

[Noons]

Ay! Check out for sparks in electrical motors....

[Rick Chamberlain]

Welcome. I know what you mean about those pesky bandsaurs - even the old arn ones. No matter how hard I try, no matter how much I spend on blades, no matter how much time I spend with my trusty TS-Aligner Jr (tmEB) and straightedge, I can't get those glue ready edges!

I go slow, no love. I speed up, no love. New bearings and tires, no love. I adjust the positioning of the saur relative to true magnetic north, still no love.

Surely, there is some book or infomercial that can save us!

I'm hoping that Mikey will be at the Mahwahkee WW show next week so he can show me (and the boys at Laguna) how to do it the right way.

Rick, willing to make 3 easy payments of $29.95 so I can get rid of my jointer, planer, and sandpaper...

(Remove the HIGH SPOTS for e-mail)

[Bridger]

come on.... two wheels, two spindles....