1/2" vs 1/4" Bandsaw Blades

[Bob Kline]

On my Jet bandsaw I used to use inexpensive 1/2" blades and had more drift than I could live with. I bought a couple of 1/2" Timberwolf blades and the problem completely disappeared. Then I (accidentally) bought a few 1/4" Timberwolf blades and the problem is back. Can it be that the difference in performance is due entirely on the width of the blades?

[John TenEyck]

Simply put, no. Drift can be due to many things, but since one blade cut straight it suggests to me that either the other blades were not equally sharp on both sides, they didn't have equal set, or you didn't get them tracking correctly on the wheels. The fact that one 1/2" blade cut straight while the other did not, shows you that blade width is not the issue.

John

[Prashun Patel]

? If you had it with the original 1/2" blade, then how can the problem be due to the width of the blade?

I think the problem is either using cheap blades (I've had this problem with both stock blades I got from Grizzly) and not using the right blade for the job (fewer teeth are more efficient, IMHO).

Bandsaw owners tend to make a lot of the importance of tensioning and the guides used. On most general purpose cuts it's just not an issue for me. Even on thicker resaws, it's not an issue.

What's the tpi on your blades? What wood are you cutting?

[Bill Huber]

I think tracking is the problem, you can change the drift just by changing the tracking.

If the blade is tracking to the back of the wheel the blade will want to drift to the right and if the blade is tracking to the front of the wheel it will want to track to the left. This is from standing on the side of the band saw looking at the teeth of the blade.

[lowell holmes]

I think tracking is the problem, you can change the drift just by changing the tracking.

If the blade is tracking to the back of the wheel the blade will want to drift to the right and if the blade is tracking to the front of the wheel it will want to track to the left. This is from standing on the side of the band saw looking at the teeth of the blade.

I agree with Bill. I have a 14" Jet. When you are setting the tracking, manually turn the wheel and adjust the tracking until the blade is on the crown of the tire and then turn the wheel manually and adjust the drift until it centers on the tire. Do not over tension the blade.

[John TenEyck]

I agree with Bill. I have a 14" Jet. When you are setting the tracking, manually turn the wheel and adjust the tracking until the blade is on the crown of the tire and then turn the wheel manually and adjust the drift until it centers on the tire. Do not over tension the blade.

On a slight tangent, you can't over tension a 1/2" blade on a 14" CI saw. If this particular Jet has a steel frame, then OK, you might be able to. With the Delta CI 14" type saws, about the most you can apply to a 1/2" blade is around 12K psi, which is at least 50% lower than the minimum recommended by most blade manufacturers (Timberwolf being a noted exception).

John

[Ivan Wolder]

Several months ago I went to a woodworking show,I attended the demo that Carter Co put on.I then followed their directions on setting up the saw and it has made all the difference,even with cheap blades. It is worth checking out.(I have no allegiance to the company)

[lowell holmes]

On a slight tangent, you can't over tension a 1/2" blade on a 14" CI saw. If this particular Jet has a steel frame, then OK, you might be able to. With the Delta CI 14" type saws, about the most you can apply to a 1/2" blade is around 12K psi, which is at least 50% lower than the minimum recommended by most blade manufacturers (Timberwolf being a noted exception).

John
I tend to agree. Except, in the case where you have an after market spring. I do have and they cautioned about over tension with smaller blades. I normally run a 3/8" blade on my saw. The instructions that came with the spring said to set the tension at 1/4" for a 3/8" blade.

I can tension a blade to the point the machine that sounds and operates differently. I don't run it there.

Also, if the blade is running on the crown of the top wheel, I have minimal deflection on the saw. The 14" Jet BS is reasonably good saw, but I agree it is not a really robust saw.
I don't need a more robust saw at this time.

[Jerry Thompson]

Take a look at this. It changed my BS problems.
https://www.youtube.com/watch?v=wGbZqWac0jU

[Lee Reep]

Take a look at this. It changed my BS problems.
https://www.youtube.com/watch?v=wGbZqWac0jU

Yep, that's one I recommend whenever I see questions on drift, tensioning, guides, etc. I have Alex Snodgras bookmarked in YouTube, although I've pretty much got the video memorized regarding technique and suggestions. His video made a HUGE difference for me.

[John TenEyck]

I tend to agree. Except, in the case where you have an after market spring. I do have and they cautioned about over tension with smaller blades. I normally run a 3/8" blade on my saw. The instructions that came with the spring said to set the tension at 1/4" for a 3/8" blade.

I can tension a blade to the point the machine that sounds and operates differently. I don't run it there.

Also, if the blade is running on the crown of the top wheel, I have minimal deflection on the saw. The 14" Jet BS is reasonably good saw, but I agree it is not a really robust saw.
I don't need a more robust saw at this time.

Even if you have an after market spring, like the one I have from Iturra, you cannot reach 18K psi on a 1/2" blade on a 14" CI Delta or similar saw unless you nearly fully compress the spring. At that point the frame bends so much that the upper blade guide goes way right and you risk breaking the upper wheel axle. You definitely don't want to run there. With narrower blades, yes, you can reach proportionally higher tension, even 18K or more on really narrow ones, though still only about 16K psi on a 3/8" one. Those with more robust saws have an inherent advantage in getting blades to cut straight because they can apply 18K psi tension, even a lot more. With the 14" CI Delta type saws running at lower tension everything has to be set nearly perfect and the blade needs to be about perfect, too, for it to cut straight.

John

[lowell holmes]

Even ------------------------------------------------ . At that point the frame bends so much that the upper blade guide goes way right and you risk breaking the upper wheel axle. You definitely don't want to run there.
John

I was not talking about blade breakage, but the saw distorting and creating issues.:)

I have watched the video mentioned in the other posts and stand corrected. Apparently, the blade should be positioned so the back of the gullet is centered on the center line of the upper tire. I will try that. If you are running Timberwolf blades, you definitely want lower blade tensions. I use the flutter method of setting blade tension on blades other than Timerbwolf as well. The aftermarket spring on my saw is Iturra.

I think we are in general agreement here.

[Lee Schierer]

As others have noted, drift can be caused by a number of factors such as uneven sharpening, improper alignment, grain of the wood, etc. One other factor is that the wider a blade is the less tendency it has to make a circular cut. If you look at a blade radius chart, a 1/4" blade can cut a 5/8" radius. A 1/2" blade can only cut a 2-1/2" radius. If you want smoother resawing with less drift, stick with wider blades. I was given a 3/4" wide blade for my 14" band saw and I love it. I have to max out the tension, but it will almost flawlessly resaw 6" material with little if any drift.

[lowell holmes]

." I was given a 3/4" wide blade for my 14" band saw and I love it."

I personally find that my 14" Jet doesn't handle 3/4" blades that well. I pretty much limit my blades to 3/8" or 1/2". I get adequate performance from the 1/2" blade. I use 3tpi stagger tooth blades. If I use finer tooth configuration, the saw does not perform. I am currently using blades from Highland Woodworking and I prefer them to other brands, except I used BC Saw blades for years. But, their marketing has gone to pot and I can't seem to find them on the net anymore.

If I have the 3/8" blade in the saw and need to to resaw, I just do it. I am not sawing veneers. If that is your goal, disregard my comments.

[John TenEyck]

As others have noted, drift can be caused by a number of factors such as uneven sharpening, improper alignment, grain of the wood, etc. One other factor is that the wider a blade is the less tendency it has to make a circular cut. If you look at a blade radius chart, a 1/4" blade can cut a 5/8" radius. A 1/2" blade can only cut a 2-1/2" radius. If you want smoother resawing with less drift, stick with wider blades. I was given a 3/4" wide blade for my 14" band saw and I love it. I have to max out the tension, but it will almost flawlessly resaw 6" material with little if any drift.


Maxing out the tension is a bad idea. It over stresses the saw and leads to early failure of bearings and potential catastrophic failure of things that should never fail under normal tension. There's no reason you shouldn't be able to get a 1/2" blade to cut straight.

John

[Lee Schierer]

Maxing out the tension is a bad idea. It over stresses the saw and leads to early failure of bearings and potential catastrophic failure of things that should never fail under normal tension. There's no reason you shouldn't be able to get a 1/2" blade to cut straight.

John

Just to clarify, I don't compress the tension spring to solid height, but I do reach the mark where it says a 1/2" blade should be tensioned, which is as high as my saw will go. This particular 3/4" blade is only 0.021 thick and is actually only .726 wide. It has about 40% more cross sectional area than my 1/2" blade. I never leave the blade tensioned when the saw is not being used and I don't do a great deal of resawing.

[John TenEyck]

Just to clarify, I don't compress the tension spring to solid height, but I do reach the mark where it says a 1/2" blade should be tensioned, which is as high as my saw will go. This particular 3/4" blade is only 0.021 thick and is actually only .726 wide. It has about 40% more cross sectional area than my 1/2" blade. I never leave the blade tensioned when the saw is not being used and I don't do a great deal of resawing.

OK, good. I guess it was your comment about "maxing out the tension" that caught my attention. My Delta has marks up to 3/4" plus even more before the spring is fully compressed. Why they ever did that is unknown. I guess maybe it was a Marketing point to ignorant customers.

John