Help, vibrating saw blade

[AlanD]

I have a question for the woodworkers.
I've been ripping some 3/4 oak boards with a Delta Shopmate table saw. I put a new Irwin 24 tooth blade on it and noticed the blade starts vibrating kinda like a harmonic. This makes my cuts uneven and a mess. When I saw this first happening I turned the saw off and checked for anything loose - all tight. I've gotten some advice saying the saw is low grade or the blade is cheap, or I need blade stiffeners.
So I borrowed my dad's heaver all metal table saw and it does the same thing. I should add that both blades cut good with not stalling or smoke. The blade's rpm rating is 6000, the saw is 4600 so I'm not exceeding the blade's rpm.
Have any of you noticed this? If so, how did you fix it?
Thanks!

 

[schor]

I would guess the blade is not right if you tried it on 2 different saws. I've never used an irwin blade, I use freud and forrest blades and my only problem is not the blades but the vibration my tablesaw has, causes tearout when working with very thin veneers.

There are many woodworking experts at canadianwoodworking.com that can probably answer to your problem.

But my guess is a the sawblade is not square to the arbor for some reason.

I have a question for the woodworkers.
I've been ripping some 3/4 oak boards with a Delta Shopmate table saw. I put a new Irwin 24 tooth blade on it and noticed the blade starts vibrating kinda like a harmonic. This makes my cuts uneven and a mess. When I saw this first happening I turned the saw off and checked for anything loose - all tight. I've gotten some advice saying the saw is low grade or the blade is cheap, or I need blade stiffeners.
So I borrowed my dad's heaver all metal table saw and it does the same thing. I should add that both blades cut good with not stalling or smoke. The blade's rpm rating is 6000, the saw is 4600 so I'm not exceeding the blade's rpm.
Have any of you noticed this? If so, how did you fix it?
Thanks!

 

[AlanD]

Steve, thanks for the response. I should have said that I didn't change blades. My dad's saw has it's own blade that he has been using.

 

[JohnG]

The last response makes it sound like you have the same vibration or wobble in 2 different machines with different saw blades so the two have nothing in common.

It's normal, even desirable, for small saws on light machines to have some wobble or run out. They won't spin true enough to produce a glue line rip like an industrial saw will, but they are less likely to stall, burn, or kick back when cutting unstable construction wood. Check the run out by taking a long narrow piece of stable material like a plywood or mdf off cut, raise the blade high, run the stock into the blade about 1" using the rip fence as a guide, and back it off carefully. Stop the saw, set the blade back into the cut, and check how much clearance there is between the blade and the saw kerf with feeler gauges. I'd expect no more than 0.005" on an industrial saw, 0.015" on a cabinet shop saw, or 0.025" on a construction site saw.

Better saw blades are tensioned. The center is expanded by rolling or hammering to put the center in compression and the rim in tension. When the saw is run to speed, centrifugal force balances out the internal stress; and it runs true.

 

[chips&more]

The last response makes it sound like you have the same vibration or wobble in 2 different machines with different saw blades so the two have nothing in common.

It's normal, even desirable, for small saws on light machines to have some wobble or run out. They won't spin true enough to produce a glue line rip like an industrial saw will, but they are less likely to stall, burn, or kick back when cutting unstable construction wood. Check the run out by taking a long narrow piece of stable material like a plywood or mdf off cut, raise the blade high, run the stock into the blade about 1" using the rip fence as a guide, and back it off carefully. Stop the saw, set the blade back into the cut, and check how much clearance there is between the blade and the saw kerf with feeler gauges. I'd expect no more than 0.005" on an industrial saw, 0.015" on a cabinet shop saw, or 0.025" on a construction site saw.

Better saw blades are tensioned. The center is expanded by rolling or hammering to put the center in compression and the rim in tension. When the saw is run to speed, centrifugal force balances out the internal stress; and it runs true.

It’s desirable to have wobble????? Sorry, you will not see any wobble in my shop! As to the vibrating saw blade. I switched from Craftsman blades to Freud blades about 25 years ago and I don’t regret a single day of changing sources. And oak wood has internal stresses. So when ripping, it can easily pinch the blade and also make it hard for you to keep the material up against the rip fence which causes more blade binding. I would get a good rip blade (Freud) and try that…Good Luck.

 

[Thomas Paine]

does it have blade guides and blade guide bearings? check them. Also check your wheel bearings on your drive and idle wheels. Check while the blade tension is off.

if it doesn't have blade guides, make some for the saw.



Sorry, nevermind, i thought it was a bandsaw!