Problem with band saw - any suggestions

[David Metzman]

I have a 1980s band saw that has developed the following problem. Background - it has a green wood blade on it that is a bit thicker then standard blades and has large teeth. The problem seemed to have developed after i tried to cut a too large and rocking piece of a log - while doing this the blade got jammed in the wood a couple of times. Now when I cut, the saw cuts angling out and the blade bows out some (so that when the cut is done it pops back straight). Any ideas on how to correct this? Thanks, David

[daryl moses]

Sounds like you kinked your blade. I've never had much luck straightening one. Try a new blade.

[Dwight Rutherford]

Agree with Daryl, replace the blade.

[Don Jarvie]

You may want to reset the blade on the wheels and make sure the guides are set up.

This happens to me quite a bit. I have a crappy Reliant 14 inch saw and if the blank wobbles it will jam. Sometimes cause it the blade to jump off the tires. When it jams I shut the saw off and use the eraser on my pencil to push the blade against the guide and slide the blank off the blade via the saw cut.

All you can really do is make sure the blank is flat and take small cuts with a sharp blade.

[Reed Gray]

It can be any or all of the following:

Not enough blade tension.

Dull blade.

Damaged blade.

Cheap blade that won't cut straight no matter what...

Bandsaw needs adjusting.

Best set up video for setting up your bandsaw is on You Tube by Carter bandsaw products. Really worth watching.

robo hippy

[John K Jordan]

I have a 1980s band saw that has developed the following problem. Background - it has a green wood blade on it that is a bit thicker then standard blades and has large teeth. The problem seemed to have developed after i tried to cut a too large and rocking piece of a log - while doing this the blade got jammed in the wood a couple of times. Now when I cut, the saw cuts angling out and the blade bows out some (so that when the cut is done it pops back straight). Any ideas on how to correct this? Thanks, David

You forgot to give the size and brand of bandsaw and specifics about the blade.

Sounds to me like you might have several problems. As others mentioned, when a blade gets jammed it almost always gets warped and needs to be replaced. You can turn the wheel by hand and put a dial indicator on the side near the back and the front and watch for variation, usually in the spot where it jamed. Usually you can see the problem area as you rotate the blade.

In my experience if the blade bows when cutting thick wood it is usually one or more of several issues: the teeth are dull or the tension is too low. (Or the blade is not right for the use.) You can sharpen the teeth your self with a Dremel and see if that helps - I usually sharpen several times before replacing a blade, search the forum for threads on this. If it still bows, try increasing the tension (or try the tension increase first). Note that the tension indicators on most saws are way off. I use a tension gauge but some people make a tension gauge with a digital caliper, some use the flutter tension method.

Since you didn't give details I'll guess you are using one of the models most common in small shops. Some older 14" Delta and Jet bandsaws are notorious for losing their tension when a tensioning bracket in the saw bends. This part is cheaply made and weak and will bend when trying to tension a blade too big for the saw (even though the saw is "rated" for larger blades). The wider and thicker a blade the more tension it needs. It is also possible that a jam put enough force on the saw to bend the bracket. A saw with a bent bracket will be difficult or impossible to tension properly. I bent the bracket on my 14" Delta once, probably because I was trying to tension blades that were too big. I bought a new, improved bracket from Iturra Design and also replaced the tension spring with a stronger one - the saw then tensioned correctly and easily. I now do all my green wood prep with a 1/2" 3-tpi blade on either the Delta or mostly, an 18" Rikon.

I'm sure you know this, at least now, but a piece of wood that is not well supported at the point of cut is likely to rock and jam the blade - very dangerous, people have been hurt and blades and bandsaws broken. The size of the piece of wood does not matter - a 14" saw will easily cut a 12" thick log of green or dry wood using a riser block - I did that for years with my Delta. However, it should never be cut across the grain, through the round part. (Actually it is possible if properly wedged and supported.) You can cut the log down the center or if short enough, stand the log on end and cut that way. If cutting down the center of the log I sometimes trim off irregularities with an hatchet or chain saw so the log will rest nicely on the table.

processing_B01.jpg processing_B03.jpg processing_B07.jpg

processing_wood_.jpg processing_wood_2.jpg processing_wood_3.jpg

JKJ

[Roger Chandler]

Sounds like you were making a dangerous cut on your saw, and are lucky to get by with just the blade being ruined.....replace blade, adjust all guides properly, and the saw tension.

[Curt Harms]

BTDT. The most practical fix is to replace the blade. Maybe keep the old one as a 'nail finder' if it isn't too bad.

[David Metzman]

Thanks for all of the replies and pictures. It is a 1980s Makita. I just upgraded the motor - some of you commented on that venture in a previous post. When I just run it it seems the blade is not straight - it seems to vibrate. I will try increasing the tension and see if I see any kinks. I think I remember noticing that the blade looked bent a bit in places. I guess the 80 lb log was a mistake. It is a new blade. Ow well. Thanks, David

[John K Jordan]

...I guess the 80 lb log was a mistake....

That weight alone should make no difference to the bandsaw as long as the table is strong enough and you have a method for dealing with the outfeed (such as a friend who can follow directions!) But again, the log really, really needs to be 100% supported from the table up, every time a tooth is in the wood! As mentioned, I cut a lot of round and irregular chunks of wood and use wedges, screws, clamps, and other strategies to keep the wood supported below the cut.

There are situations where you can get away with some minor unsupported areas but that's tricky - mostly it's just a disaster on a hair trigger.

JKJ

[David Metzman]

John - what bandsaw do you have? Thanks

[John K Jordan]

John - what bandsaw do you have? Thanks

The bandsaw I used when taking the photos posted earlier is a Rikon 18". It can handle about 12" from the table. It can easily handle a heavy log as long as I set it down gently and don't drop it on the table. I can handle around 2' lengths by stopping the push at some point and walking around and pulling to finish the cut. I've cut some that were 12" in diameter and perhaps 3' long. For that I get someone to support the far end as it comes off the table while I continue to guide the cut. I have to make sure they understand to simply support the weight and not try to help by pulling the log! With a second person I get help to lift the log to the table.

If the log is over 12" in diameter I cut it down the middle first with the chainsaw. If it is over 12" in diameter but less then 12" long, I stand it on end on the bandsaw table and cut through the pith first, then lay it on the flat and continue.

Before I got the Rikon I used a 14" Delta with a riser block which also gave a 12" cut. Looking back, I cut some logs I find a little difficult to believe today! The cut was slow with that underpowered saw, especially for hard woods like osage orange and black locust. I've always used 3-tpi blades with these saws and now stick to 1/2" blades. For a while, I experimented with wider blades on the smaller Delta, up to 1" - way to wide to tension properly on that saw! I did a lot of resawing on that saw as well, including cutting a 12' douglas fir 2x12 into 4 boards for a friend. It worked beautifully, but if I had had more experience I probably wouldn't have even tried!

BTW, I do have a small WoodMizer band mill behind the barn that is far better for this sort of thing but has some limitations - I have to make a special way to hold any log under 4' long. It's only worth it when I have a bunch of turning blanks to make such as these for a friend:

sawmill_blanks.jpg sawmill_blocks.jpg

JKJ