Help with Jet bandsaw - please

[George Robin]

Hello all,

I have an enclosed base Jet 14" bandsaw (don't have the model number with me). I bought this new.

Problem I'm have is how the blade tracks through wood as I'm cutting. The balde seems to twist once I start a cut. I've tried everything from, blade tension, tracking, adjusting cool blocks, different blades, etc. no luck.

Here's why I'm confused.....we have a similar Jet bandsaw (14" open stand) at work. I have set this saw up, it has been abused by several people here, and this saw works like a charm.

Any ideas?

Thanks
george

[tod evans]

george, i`m bettin` on a dull blade or too little tension or both....02 tod

[Bill Kay]

Hi George, I have the same model Jet Bandsaw you describe. Every time this tracking problem has happened to me it was caused by a dull blade. Change the blade and give it a try. regards,

[Stu Ablett in Tokyo Japan]

I'd agree with tod, the part that is causing the trouble is most likely at fault.

That being said, if the tires are in BAD shape, you should have a look at them too.

Cheers!

[Bartee Lamar]

Blade on upside down ?

[George Robin]

Thank you all for the replies....

What is puzzling me, is I have tried at least 5 or 6 blades since I bought the saw and have always had the same problem. These were all NEW blades. I've adjusted blade tension up and down, no difference.

Tires, they show little wear (very little)

I was cutting a piece of pressure treated 2x yesterday.....as I was cutting, the balde would wanted to twist.

Maybe I haven't cranked the blade tension enough?

How do you know when you have enough tension?
Is there a such thing as too much?


Thanks
George

[Pete Bradley]

Can you clarify what you mean by twist? Does the blade try to bow between the two guides, does it vibrate, or does it do something else? What size/tooth bands are you using?

I gather you bought the machine used. Did it ever not do this?

What condition are your blocks in?

Pete

[George Robin]

Hi Peter,
Actually, I bought the saw new, adn it has always do this. I just haven't tried to do any critical cust with it.

Twist, as I'm pushing the board into the blade, the blade itself starts to track mostly to the right. If I skew the board going into the blade, I can follow the line. However, I'm puting side load on the blade this way.
The guides are in good shape and adjusted very close to the blade but not dragging. They are also adjusted to the edge of the tooth gulleys (? is that what they're called?).
More feed pressure woorsens this, less pressure doesn't do anything.

I've tried blades with 6tpi and 14 tpi. (1/4 - 3/8" wide)

No vibrations, or anything out of the ordinary.

Still clueless in RI

[tod evans]

Hi Peter,
.

I've tried blades with 6tpi and 14 tpi. (1/4 - 3/8" wide)



bingo! here`s the problem as i see it.....try a 1/2" 4 tooth blade from any manufacturer and see how it behaves....02 tod

[Pete Bradley]

I don't have a lot of experience with high tooth counts and I'm not sure that's warranted. I use a 3/8" 4TPI for almost everything. It may not entirely explain your problem though. Some blade drift (you know blade drift, right?) is to be expected, but not to the point of putting pressure on the blade.

Assuming the band tracks normally in the center of the wheel, it's gotta be in your guides or blade. I suggest doing the following with a good-quality 3/8 or 1/2" band:

1. remove the band, loosen up the blocks, and make sure the faces of the blocks are not chewed up and meet squarely.

2. If you have a thin metal machinist's ruler or similar, pinch it between the bottom blocks and check that it looks straight. Do the same with the top blocks. A lot of machines have a set screw that allows you to adjust the angle of the top guide, but I'd leave it alone unless it's way out.

3. put on the band but leave the blocks and thrust bearing backed off and get the band tensioned properly. Spin the wheel by hand only while making adjustments to avoid launching the band. If all's well, you should be able to run the machine this way. Verify tha the blade doesn't flutter (but don't adjust tension or anything else while running).

3. now adjust the blocks and thrust bearing to the band, being careful not to push the band to the side. The thrust bearing should be about 1/64 from the back of the band. The blocks go about 1/64+ behind the gullets. I use a thin piece of cash register receipt paper to adjust the clearance.

Hopefully by going through these steps, you'll identify the cause of the problem or make it go away.

Pete

[George Robin]

Tod, so I'm using blades with too many teeth? How do you get a cleaner cut? Should I only be suing my curent blades for thin stock?

Pete, thanks for the instructions. I will try these tonight.

I appreciate all the responses.

George

[tod evans]

george, pete gives you very good set up advice, and yes you`re running to fine a blade especially on pressure treated wood. think of treated as green wood that`ll eat your blades faster( the chemicals do eat steel). i think you`ll find than no blade will give you a flawless finish so go for ease of cut first then after you`re able to cut well with your saw start playing around with tooth count and geometry to find the happy medium between accuracy and finish.....02 tod

[Perry Holbrook]

Band saw blades wear quickly once they get hot. They get hot if you cut thick stock with higher teeth count because they can not carry the dust away from the cut fast enough. Cutting dirty stock and pressure treated stock can make this worse.

Sounds to me like you are using blades that dull quickly either due to poor quality of the blade, wrong blade selection and/or cutting stock that is hard on the blade.

Perry

[Pete Bradley]

By the way, you can get a very clean cut even with a lower TPI. I find a 4PC Timberwolf will give you a cut that only requires light scraping in most hardwoods.

Pete

[Aaron Beaver]

How do you know when you have enough tension?

Thanks
George

Lots of people use this method

http://www.suffolkmachinery.com/six_rules.asp

[Curt Harms]

Lots of people use this method

http://www.suffolkmachinery.com/six_rules.asp

This method works well with Timberwolf blades, which are intended to be run at tension less than the tension used on other blades, e.g. carbide. Has anyone used Timberwolf's method on carbon steel or bimetal blades? I've found that using excessive tension on Timberwolf blades doesn't help with tracking problems (due to a dull/worn blade that felt sharp to me:o ) A good Timber Wolf blade with too much tension seemed to produce a rougher surface without improved tracking compared to the same blade tensioned using the Timberwolf recommended method. That has been my experience anyway.

I hope this makes sense

Curt

[Bruce Shiverdecker]

Here's my .02 about the Timber Wolf blades. We sell them. I am told that these blades are "Low Tension" Blades. If you Over-tension them, they WILL break early! The way I was told to tension them is:

Install the blade with all the bearings/ cool blocks backed off. Tighten it till it is snug. Turn the band saw on and tighten it till the "Wobble" goes away. Make one more turn on the tension knob and it should be correct!

Other blades should be tensioned to the specifications listed in your machine.

Bruce

[George Robin]

I wasn't able to try these tings last night. We are getting ready for a small vacation, our first vacation this year. I will hopefully get to try them tonight.

Thanks again for all the ideas.
George