Bandsaw blade jumping off - any advice?

cmd

cmd

Joined
Feb 7, 2004
Messages
1,207
It's the least expensive horizontal/vertical Norther Tool model, and I use a bi-metal blade and cutting fluid.

Any advice on how to improve keeping the @#$% blade on the wheels?

Crank down the blade tension really hard? It's "hand tight" but I could get it a lot tighter with a strap-wrench.

Replace my blade with more (20-24) teeth per inch? I think it is currently 8-12.

Chris
 
is the saw new or old? are the bearings on the drive and driven wheel worn? is there any buildup on either one of the wheels? are the guide bearings worn or loose? do you have the correct width blade on the saw? you might be getting the blade too tight. there should be a little play side to side but not much. overtightening the blade too tight will cause it to break not to mention putting undue stress on the bearings
 
Lots of good things to check!

is the saw new or old?
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less than 2 years old

are the bearings on the drive and driven wheel worn?
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no

is there any buildup on either one of the wheels?
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no

are the guide bearings worn or loose?
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no

do you have the correct width blade on the saw?
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yes

you might be getting the blade too tight. there should be a little play side to side but not much. overtightening the blade too tight will cause it to break not to mention putting undue stress on the bearings
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This is very interesting, I probably am overtightening the blade because it does not have any side to side play.
 
cmd said:
Replace my blade with more (20-24) teeth per inch? I think it is currently 8-12.

Chris
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How thick is the stock you're cutting? I was using a 14-18 tpi blade and it started jumping madly when I tried to cut 1/16" stock. Got a 24 tpi blade
and the problems vanished.
 
dlpierson said:
How thick is the stock you're cutting? I was using a 14-18 tpi blade and it started jumping madly when I tried to cut 1/16" stock. Got a 24 tpi blade
and the problems vanished.
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I'm cutting 1/8" stock with it, and feeding it by hand in the horizontal position is the most troublesome.

24 tpi may very well be the solution, excellent!

Any other suggestions on how to improve the situation?
 
Not sure if it will help but you need a much finer tooth blade for 1/8" stock. You want a lest 3 teeth on the steel, in the cut, 8x3=24. Your blades will last a lot longer and probably stay on better.

My Grizzly is 16 years old, I have two other larger saws but still use the little Griz the most. I hand tighten mine very tight, if I run it any loser, it will jump off. Also, cutting curves will cause the blade to jump. These saws were designed to cut straight lines. A slight curve should be OK.
 
I had the same problem on mine. The bearing on the top wheel was not fully seated in the hub. Tapped it in with a 2 x 4 and plastic hammer and no problems since.

There is also a tracking adjustment for the top wheel that might help.

Rob!
 
Is the blade hanging and then jumping off or is it just running along and jumping off? If the former, you might want to switch to a finer tooth blade.

Jim
 
Thanks guys!

Everything else checks out and seems to be solid so I'm pretty confident that the new blade is going to be the solution. I'll also go with a little bit less tension.

Chris
 
Don Hanson III said:
Not sure if it will help but you need a much finer tooth blade for 1/8" stock. You want a lest 3 teeth on the steel, in the cut, 8x3=24. Your blades will last a lot longer and probably stay on better.

My Grizzly is 16 years old, I have two other larger saws but still use the little Griz the most. I hand tighten mine very tight, if I run it any loser, it will jump off. Also, cutting curves will cause the blade to jump. These saws were designed to cut straight lines. A slight curve should be OK.
Click to expand...

After working many years as a millwright and in fabrication shops, Don's advice is right on! You need 3 teeth minimum in the steel for you to get the best performance out of your saw and blade.

I second this as the reason you're experiencing trouble.

Ickie
 
I have same exact saw, from HF. It is a true jewel of metal BS, dirt cheap,
and when tuned properly, 100% reliable.

- you don't have to tighten the blade past the point you reach with your hands

- do look at alignment of the wheels. They need to be coplanar and it is
really ez to adjust if they are not

- 12 TPI will work just fine with 1/8 stock. The 24 tpi will last longer, but will cut noticeably slower

- adjust the back bearings so that they are engaged during the cut and don't let the blade to move back too much

- lower the upper guide all the way when cutting sheet stock

- make sure the blade is nice'n'sharp bimetal, NOT the uber cheap plain
carbon variety . ENCO & MSC, McMaster all carry excellent blades in $17-20
range

- don't push it too much when feeding the stock into the blade. When sharp, blade will cut
with minimal pressure.
 
I,m not familiar with your band saw but if it has tires on the wheels check for debris under the tire. Don't know how it gets there but I had the same problem, I had to take my saw apart twice before I found the smallest piece of crude had fused to the wheel
 
Hey Chris,

Years ago, when I was a hack machinist working in Raleigh, I bought one of these saws for the shop. Worked great. Last I knew they put the friggen thing INTO PRODUCTION!, Amazing.

Then a few years later, I got one for myself for my little shop. I've had it for many years and have gotten great service from it. I can't bear to part with the old saw.

A few years ago, I got one for a little shop we were putting together back in R&D at TR ENG, the stupid thing could not be made to keep a blade on. Several of us fooled with the thing and we could not figure out what was the problem. A bunch of engineers and we were (and are) stumped... Beats me. I tried a high quality Starrett blade (the best IMO) adjusting the toe in of the pulley, adjusting the bearings, anything we could think of. Put over an hour into it. No improvement. I guess we must be pretty dumb...

I can pass along a little bit of useful knowledge here though. Bandsaws require fairly high blade tension. The little 3" knob on the top of these things does not allow the average human to obtain the correct blade tension, so they ship with a little spanner wrench that fits in those two holes in the knob. I don't think you can over tighten it by hand. Higher blade tension may help your problem. It will certainly help keep your cuts straight.

The blade that ships with these saws is damn near useless. You could probably use the metal strap holding it to the pallet and get better service. The new blade will probably help.
 
Thank you all so much! My bandsaw is working like a dream now.

The solution? 24 TPI was what it took to get it working smoothly and staying on the wheels.

Nathan, great advice on cranking up the tension. The cuts wander much less and now I agree that the cheap little saw is a treasure of tool.

Thanks again guys, I really appreciate it. The quality of my life in the shop just went way up.

Chris
 
I had never heard of using cutting fluid on a bandsaw??
Can't that lubricant cause the blade to slip on the wheels?
That blade needs a lot of friction to track properly.
 
Never heard of cutting fluid on a band saw???? (just kidding)
That is how they keep the big industrial unit blades from burning up.
My big band saw has a coolant pump and a three gallon tank. I use water soluble coolant oil. The blade never slips of jumps off. On my small saw, I don't use coolant. The blade needs a lot of tension and a high tooth count.
Stacy
 
Hey Chris,
If your saw has a D shaped handle on the frame near the blade tensioning knob and you want to save yourself some knuckle skin and aggravation, remove that thing. It makes it really easy to get a proper grip on the tension knob and will greatly increase the positive energy in your shop. I used an angle grinder to remove the handle from mine and it was the best 15 minutes I could have invested.
 
bladsmth said:
Never heard of cutting fluid on a band saw???? (just kidding)
That is how they keep the big industrial unit blades from burning up.
My big band saw has a coolant pump and a three gallon tank. I use water soluble coolant oil. The blade never slips of jumps off. On my small saw, I don't use coolant. The blade needs a lot of tension and a high tooth count.
Stacy
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I understand that -0 but I'll bet those saws have guides and such to help keep the blade in place as well as much higher tolerances in wheel alignment.
The small, and rather low-tech, cut-off saw in question here may not be able to keep a "grip" on that blade if lubricated.
I'd leave it dry.
 
I can only speak from my experience, and obviously I am no expert, but using fluid with this saw provides a couple of benefits without causing any problems.

Since switching over to a 24 tpi blade there has been no slippage or jumping off, and I did a lot of cutting last night :)

Using some fluid on the cut seems to keep the metal cooler, cut a little more smoothly, and helps to keep the metal filings from getting all over the place. Also when chopping things like small tubes it tends to keep the tube from spinning.

I have tried cutting with and without fluid and personally like how it works with fluid much better. This is of course just the results of trial-and-error on my one cheap little saw.

Chris
 
well how bout this. My bandsaw jumps the blades off of hte bottom wheel towards me no matter how I have the top wheel adjusted, even with the blade all the way to the opposite side on the top wheel. It still jumps off to the front no matter what I do, no matter which blade. It is a Ryobi 9" model
 
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