Q: bandsaw tuning

[Andy Resnick]

I have a 14" Jet bandsaw that as of recently refuses to cut in a straight line. The blade consistently drifts at about a 10 degree angle, making attempted 90 degree cuts come out to something like 80 degree cuts. I tried tuning the saw the following way:

-Checking blade tracking on both tires (tires look worn, but servicable. When the rotation direction is reversed, the blade shifts position to a new location, about 1/2" drift, and returns back to original position when normal rotation is resumed). During normal rotation, blade tracks along top of tire.

-Checking guidepost alignment. Guidepost is as parallel as I can make it.

-Checking blade tension. As best as I can figure, the blade is tensioned properly.

-Checking guideblock alignment. Guideblocks are the black plastic type, but are installed correctly.

-Checking bearing alignment. Blade overlaps bearing by 1/4" or so, more than the recommended 1/8"

To be sure, on the bandsaw I have limited ability to remove wheel twist and out-of-parallelism. Besides, until recently the saw worked perfectly, so I am assuming I simply need either new tires or a new blade. The tires are original (10+ year old saw), and the blade could be losing the set.

As it stands, the bandsaw is unusable, and I would appreciate any insight or help. None of the websites I checked addressed this specific problem, other than providing general tuning procedures. Thanks in advance.

Andy

[Lawrence L'Hote]

It's 'normal' to experience blade drift. You didn't mention you changed the blade. Get a new(good) blade (i.g. Lenox). IIRC the drift is caused by the way the teeth are cut.

Larry

[George]

Bunch of reasons why blades lead. One of the most popular at this turner's house is sand in the bark of pieces being prepared for the lathe, though teeth which are stamped versus ground, improperly set, or a bit dulled from touching the guides can certainly do the same. As can blades with a bit of a burr in the back, away from the teeth. This can be turned in use on the saw as well.

When it leads so much that it irritates, replace, and don't be surprised if the new one leads a bit, too.

[nospambob]

[Layne]

snip

It sounds like your blade is worn. If you think the wear is abnormal check that the blade isn't touching the metal insert plate in the table. This will wear out a blade in no time. This is the reason I switched to those plastic inserts. If you're considering getting a new blade try Timberwolf. They're very good blades and track straight. I set my fence parallel to the blade and I get straight cuts. Ususally drift is caused by improperly set teeth.

Layne

[L Anthony Johnson]

Take a scrap piece of wood and run it through the bandsaw.

The blade will drift, but you will have the angle of drift on the scrap piece.

Measure the drift angle on the scrap piece of wood with a Sliding T-Bevel / Bevel Gauge.

Adjust your fence on the bandsaw to the angle on the bevel gauge.

When you run another piece through , your cut should be straight as you have accounted for the drift in the blade by moving the fence parallel to the drift angle of the blade, rather than the blade itself.

L Anthony Johnson

[Jeff Gorman]

"Andy Resnick" wrote

: I have a 14" Jet bandsaw that as of recently refuses to cut in a : straight line. The blade consistently drifts at about a 10 degree : angle,

There is a great deal of lore about bandsaw drift, but is it really asking too much of a narrow bandsaw to ask it to cut parallel to a fence?

Try stretching an elastic band between index finger (or any other that you like!) between the index finger and thumb. Apply pressure to the edge of the band and observe the inevitable twist.

I find that the drift angle even varies with the type of wood being cut.

People do manage successfully to cut veneer with a narrow bandsaw (I believe that anything less than 3in or 4in is classified as 'narrow'), but I'm pretty certain that the principal factor is blade sharpness, which, sadly, doesn't last all that long.

Jeff G

-- Jeff Gorman, West Yorkshire, UK Email: username is amgron ISP is clara.co.uk

[mike]

Try a new blade, although I do not think that is the problem. Even with a new blade and new tires , you may have a tracking problem.Check for wheel alignment between top and bottom wheels, this is called coplanar when they line up at four points. Place a straight edge against the top and bottom wheels next to the hubs. The wheels shoud touch the straight edge at two points on each wheel. After this initial setup you may have to shim or remove a shim if the tracking knob does not allow you to get coplanar. When done, move the wheel by hand , adjust tracking so blade is fairly centered. Blade tension is usually about 1'4" to 1/2" play with moderate pressure. The blade should stay on the wheels at the same position whether you turn (by hand) forward or backward. Try the saw, if problem persists change blade, then change tires if needed.

[mike]

Try a new blade, although I do not think that is the problem. Even with a new blade and new tires , you may have a tracking problem.Check for wheel alignment between top and bottom wheels, this is called coplanar when they line up at four points. Place a straight edge against the top and bottom wheels next to the hubs. The wheels shoud touch the straight edge at two points on each wheel. After this initial setup you may have to shim or remove a shim if the tracking knob does not allow you to get coplanar. When done, move the wheel by hand , adjust tracking so blade is fairly centered. Blade tension is usually about 1'4" to 1/2" play with moderate pressure. The blade should stay on the wheels at the same position whether you turn (by hand) forward or backward. Try the saw, if problem persists change blade, then change tires if needed.

[Rodney Myrvaagnes]

I think you are right, although I have what seems an anecdotal exception. All my experience with larger bandsaws required stoning each new blade and fiddling with everything. I have not had a shop with large tools for a long time.

So when I bought a tiny Inca bandsaw to use in my small city apartment, I didn't expect much. I was astonished that the blade that came on it (about 6 mm wide) cuts parallel to the fence in boxwood and in pine, about as different as two woods can be.

The saw has 8-inch depth and is made of cast aluminum. I can pick it up with one hand.

I dread having to replace the blade, beacause I can't believe the next one will behave as well.

Rodney Myrvaagnes NYC

We have achieved faith-based science, faith-based economics, faith-based law enforcement, and faith-based missile defense. What's next? Faith-based air traffic control?

[Old Nick]

On Fri, 20 Aug 2004 08:20:46 -0400, Andy Resnick vaguely proposed a theory ......and in reply I say!:

remove ns from my header address to reply via email

4 words. The Bandsaw Handbook. Mark Duginske.

3 words. Probably new blade. Is this the first blade ever?

It is possible to work with a saw that does what you descirbe. You simply start feeding ghe wood at the angel the saw wants.

***************************************************** Marriage. Where two people decide to get together so that neither of them can do what they want to because of the other one.

[wdh]

I have to disagree with Layne. Timberwolf blades are the worst ones I've tried. Notice I didn't say use. I bought a three pack (1/8") at a show, and the steel used to make them is so soft, I bent the first two just trying to get them on the saw. I managed to get the third one on without a bend, but the "low tension" instructions that came with the blade are absoulute fiction. Once I got the tension up just past where I normally set it for 1/8" blades, the blade finally stopped fluttering. Even so, it cut the widest kerf of any blade I've had, and the blade snapped after less that 30 minutes of cutting. Probably because the tension had to be set so high.

I have noticed that there are "gimics products" in certain industries. Golf and fishing certainly come to mind, with products that are this year's fad and promise far more than they deliver. Woodworking shows have these types of products too. Timberwolf bandsaw blades are among them.

Just my $0.02.

[GerryG]

[WD]

I agree with you don't buy Timberwolf. I suggest Viking's blades from Lee Valley. I thought I am the ONLY one here who had used Timberwolf blades and was convinced that the blades were trashes.

[Bruce Barnett]

Viking blades ARE Timberwolf blades.

[GerryG]

A very good point, Bruce. It's interesting also, to read the description. It seems to me that Lee Valley usually checks this out and writes much of the prose themselves. They note the absolutely straight cut, which is also something I've seen, as there's virtually no blade lead.

The only issue I've had was the deviation from flat in the blade, which causes a slight back-and-forth movement, but this was primarily in their 3/4 blade. As to lasting, I bought a bunch of them maybe 4 years ago, and only a few have worn out.

GerryG