Bandsaw questions: zig zag cuts, and blade options...

If it’s in the budget, you might consider either of Mark Duginske’s books. I also have one by Lonnie Bird called The Bandsaw Book that is more basic but gives good information about tuning. Also, there are several good articles on Fine Woodworking’s website. I’ve even seen an article for a shop-made tension gauge out there.

-- Jeff, St. Paul, MN

I believe the waving that you are seeing is a vibration within the cutting line. to me it looks like the teeth cutting a wavy line as it vibrates. The rows to me look like every tooth on the left and right cause the line.

I don’t know what causes it but I’ve seen it before. I’m currently using a Laguna Resaw king blade at $1.75 per inch. but they are carbide teeth and they will resharpen them. A fantastic cut. it just requires sanding to make it smooth.

-- Karson Southern Delaware karson_morrison@bigfoot.com

Without seeing a pic – hard to tell if you’re talking about a normal bandsawn surface or not…does sound like it could be tension related…the old adjuster/spring in there may be crapped out. Might want to look into replacing that…I had to, because mine broke…I think it was a $20 part or so. The latest findings have pretty much crushed all the myths and state that stock blade tensioners are okay to gauge tension by.

I use the Timberwolf blades – really like them and pretty much alternate between two blades…the 1/4 6tpi hook and the 1/2 3tpi hook…

-- Dorje (pronounced "door-jay"), Seattle, WA

I belive the books Jeff referred to have good information on blade selection. Also, LJ Tony Ward has some info on his web site.

http://www.tonyward.org/index.php?option=com_content&task=category&sectionid=3&id=38&Itemid=90

-- We must guard our enthusiasm as we would our life - James Krenov

Wavy cut may also have to do with the guide blocks being too far from the blade sides to properly support the blade. You explained your problem and then answered it when you said that your guides need to be replaced.

Hi Ben.

Sounds very similar to what I’m seeing. I also have a Jet 14” and Timberwolf blades. I’ve done my best Duginske tuneup adding only a wheel brush and cool blocks.

On my 3/4” blade I can see it twist when the weld comes around and assumed that was the problem. But I’m getting similar rough cuts with my 1/4” blade too. And on that one I see no twisting.

I’m going to call Iturra Design. Their catalog is a book on band saws – highly recommended. I’ll try one of their woodslicer blades for the resawing. Not sure yet what to try for the smaller cutting.

-- johnjoiner

How prevalent is the zig zag? If I examine my blade closely, it too does a zig zag that stays within the saw kerf. Almost like it bounces back and forth between the cut surfaces, but it does not wander and I don’t consider it a problem (Jet 14 with timberwolf blades, btw). Funny as I just noticed this the other day and now you ask about it.

There is no one blade fits all scenario here. Generally it is assumed that you should try to keep 3-4 teeth in the cut at all times. This will obviously vary with workpiece thickness. Sawing 1/4” stock would need more TPI than 3” thick stock. For tight curves I use a 3/16” blade. For resaw, 1/2-3/4”. 3-4 TPI, sawing wet turning blanks, 1/2, 3 TPI.

-- Just another woodworker

Lots of good stuff here. I ordered a couple new timberwolf blades for starters, and will pick up a pair of ceramic guide blocks this coming weekend (my parents live near a rockler AND a woodcraft). Since it’s still useful discussion, I will take a picture of the cut when I get home and post it. Thanks for all the good info so far!

-b

Well, I’m an inadvertent liar. There will be no pictures, since my wife took the camera far far away (and not to return until after X-mas)... In any case, hopefully new blocks and blades will solve the problem.

-b

Ben, I don’t know if you subscribe to American Woodworker or not, but I got my new copy in the mail today and there is an article in there about tuning bandsaws.

-- Jeff, St. Paul, MN

There is also the possibility that your wheels are out of balance. Any easy way to determine this it to remove the blade and then do a spin test. (1) spin the wheel once (2) mark the bottom of the wheel after the spin; (3) give it several spins. If the point you marked in step 2 is always the low point, the wheel is out of balance.

-- Jeff, St. Paul, MN

I know the perfect solution! There’s this woodworking contest I know of where the grand prize is a new Steel City band saw …

Seriously, I just ordered a 3/4” woodslicer and a 1/4” bimetal blade from Iturra Design to throw at my problem. We’ll see if it’s the blades or my setup.

-- johnjoiner

The 1/4” bimetal blade from Iturra is sweet. Threw it on and made a couple test cuts in 4/4 ash before helping the boy cut out his pinewood derby car. Much smoother cuts than with my other blades. Don’t have time to try the 3/4” blade tonight. Hopefully tomorrow ….

-- johnjoiner

sounds like a tension problem! Despite applying / setting a high tension I’ve not broken a 1/4” blade, ever.

If everything else is set up properly, e.g. table square to the blade, blade operating in a vertical position, guides in place, what else have you got to loose but by applying more tension?

At the end of the day the less machine marks the better, the less sanding to do. Sanding is the time consumer and bad for your health!

Good Health
Tony Ward

-- Bandsaw Box Plans