Laguna 14SUV Bandsaw and Resaw King Blade Problem

[Bernie Kopfer]

Last night I decided to once again try to get the 1" Resaw King blade to track properly. I Cleaned the blade and tires. I made a jig and made sure the wheels were coplanar, and yes they are, even under full tension. Centered the blade on the upper wheel with the teeth just off the tire. But as before the blade on the lower wheel tracks forward so the teeth are actually in front of the wheel a eighth or more inch. This is clearly visible on the post so that if the guides are adjusted correctly at table level when lifted to full height they push the blade forward about 3/32 in.
I finally gave in and adjusted the post and table to the blade since I intend to leave this bode on all the time. (I have a small Rikon for curve sawing etc) This blade has never been my favorite and it was recently factory resharpened. The cuts I made last night are very acceptable but i am annoyed that the blade does not ride in a coplanar manner on the wheels. Does anyone else have/had this problem? And are there any suggestion as to why and what to do about it? Thanks.

[John TenEyck]

It's normal for the blade to track towards the front of the lower wheel under normal tension. Nothing wrong there.

But you should adjust the blade so that it's centered on the upper tire, and then adjust front/back so that the saw cuts straight.

I wonder if that saw can tension a 1" blade. Maybe, but a 3/4" might be a better choice.

John

[Bernie Kopfer]

I too have wondered about a1" blade, but that was what Laguna was selling with the saw when I bought it..... But now I see they promote a 3/4 blade. Others here at SMC have said the 1" blade works ok on this saw and it is a well built unit.
Thanks for the info about tracking. I did not know that and perhaps it really only showed up significantly with the wide blade.

[Van Huskey]

The LT14SUV has a fairly small crown so I have an issue riding it forward of the upper tire centerline especially if you get any tooth/tire contact with it centered. But it will try to pull "up the hill" so if there is no tooth/tire contact centering it may settle your concerns about the tracking on the lower wheel.

The first question I have is the blade cutting exactly parallel to the fence, if it is not it will contribute to poor quality of the cut.

Honestly, the 1" RK is going to be under tensioned on that saw, I don't care what anyone tells you. The SUV is a solid 14" saw but...
To give you an idea I can't quite get 30,000 psi on a 1" Trimaster on a Minimax MM20 and while the Trimaster needs about 25% more spring pressure to get to equal strain (since it is thicker gauge) if you compare the spring in the MM20 to the SUV you will see they are quite a bit different in the beefy department. When it comes time to replace the RK go 3/4", the lower tension you can get on the 1" will have lower frequency/high amplitude harmonic vibrations in the blade which results in a lower cut quality. Also be aware that hand feeding, especially tall resaws will exhibit a lot of hesitation marks which some try to blame on the blade.

Check and account for any drift or lack of parallelism between the fence and blade, crank the tension as high as it goes and let the blade ride more to the center of the top wheel and see what that does for you.

[Morey St. Denis]

There were some basic math errors in certain information you have been given regarding spring tensioning force required for a 1" Lenox Tri-Master blade vs the 1" Laguna Resaw King. As Van has correctly pointed out, tension, compression, stress & pressure are conveniently normalized and expressed in engineering terms of force per unit area; in the Imperial measuring system we often use: pounds/in^2, Lbsf/in^2, or simply PSI. The error appears to be in accounting for just how much thinner band thickness is for a Resaw King vs. Tri-Master or most any other blade in resaw application... My information shows that thickness of the band (sometimes called "backing" in the instance of tooth inserts as opposed to tooth "set") is 0.035" for their 1" blade, while that of your 1" Resaw King is only 0.024". Saw kerf (material wasted) is a standard 1/16" while kerf width for the RK is only about a millimeter or 0.041", a full 34% less material wasted... Facts are that it will indeed require nearly 50% more spring force of your saws structural frame to equivalently tension a TM blade (not about 25% more as had previously been mentioned).

I also humbly disagree with the assertion: "the 1" RK is going to be under tensioned on that saw, I don't care what anyone tells you!". While I do not have precise figures for comparitive width across the gullets available at hand this moment, we can reasonably assume that these could be roughly similar in the range somewhere around 7/8". Regardless, it shouldn't matter much, it's that substantial band thickness differential that really counts, the RK has only 2/3 the backing width of the TM band profile. 0.035" x 0.88" = 0.031 in^2 of area vs. 0.024" x 0.88" = 0.021 in^2. The Force difference required in jumping tension up to a equivalent range for that Lenox band is 0.010/0.021, about 48% more spring force demanded if you were to attempt a 1" TM.

Another great benefit of reduced backing band thickness over every other band saw blade marketed is in lower bending stress repeatedly imposed on a band, especially that weld joint, and in each tooth's brazed carbide juncture to the band. While the former example illustrates a simple linear relationship between width and area to tensile stress, with bending stress it's actually an exponential relationship to thickness! The highest bending stress imposed on a band conforming to smaller tire diameters is an exponential inverse function; so a simple reduction by 1/3 in the band thickness can result in a reduction in the range of halving both stiffness and peak band stress... Applied engineering brilliance on the part of Torben Helshoj! The Lenox Tri-Master employs a "triple chip" grind to their carbides, resulting in a general multi-purpose blade that works well on ferrous and non-ferrous metals, its application for wood appears strictly an afterthought... The Resaw King is optimized for use in exotic and other valuable hardwoods, it can readily accommodate band saws as small as 14". Due to greater band thickness and substantially increased bending stresses, I would not think that the TM could be recommended for 14" wheeled saws. The RK raking teeth reduce the perturbation of certain harmonic vibrations by employing variable pitch spacing in the range of 2-3 TPI; a feature not afforded by many other multi-purpose blades. Smaller kerf width also delivers proportionally reduced power demands in tall resawing cuts. A lot of people may be happily getting away with certain subtle misapplications in their power equipment, but there's no cheating the mathematics and material science applied to our craft.