What's the proper tension for a Resaw King?

[glenn bradley]

Interesting discussion. Those pics look like they may be the result of an excessive feed rate. I have used the flutter method (see Suffolk's site) on my Resaw Kings since day one. I cut 1/16" veneer between the blade and the fence using minimal tension. More years ago than I can remember I embraced the method of proper setup and alignment of the saw making your blade really want to cut true. I've been riding that horse ever since ;-) I know there are other methods of making a saw cut along the line you want and if those are working for you, keep doing that. There are always more ways than one to skin the cat.

[John TenEyck]

That's what I understood from reading books and other posts. What had me confused was the idea of less tension to get rid of flutter. You wrote in one post that you can get rid of flutter if you release the tension on a blade, but then in this last post state that to get a straight cut you must have higher tension.

Anyway, thank you for the earlier reply. I went ahead and bought a tension gauge that should arrive in a few days. I'll be able to set a blade to the right ksi right off the bat without guessing.

"The FB 510 ain't so capable when it comes to tension." I'm not sure what you mean by this. When researching bandsaws last year I did not come across any negative information regarding the Felder machines.

Joel, I don't think I ever said "release the tension"; more likely I said reduce or decrease. And, yes, higher tension makes it easier to cut straight. Those are not mutually exclusive comments. It doesn't matter if you increase or decrease the tension to stop flutter, the point is to change the frequency so that the blade stops fluttering. There can be several harmonics in the blade, related to different frequencies and different values of tension. Could be at low tension, could be at high tension. In all cases, you decrease or increase tension to stop the flutter.

If you look back through the archives you will find at least one not so favorable review of the FB510 with respect to tension. The author was unable to get 25 ksi on a Woodmaster CT (IIRC) and Felder was of no help in even telling him what the spring constant for the spring in that saw is. That series of posts is what suggested to me that you might be able to get 20 ksi on the thinner Resaw King.

I've been thinking more about your comment that you couldn't get the flutter to go away no matter how much you cranked up the spring, all the way to max. There are only two reasons I can think of for that to be true. One, the spring reaches a point where it no longer adds additional force, or two, the frame of the saw is deflecting disproportional to the added force. If you are fortunate, it's the spring, which can be replaced by an aftermarket one, which I think the author of the other thread did, which, if true, suggests the spring is the problem. One way to prove which is the source of the problem is to install a dial gage between the upper blade guide and table. Also, clamp a set of 6" Vernier calipers to the blade using two small clamps. That will serve as a poor man's tension gage. As you increase the force on the blade, starting at zero, you will see the dial gage compress, ideally very little, but it will. At the same time the calipers reading will increase. If the gap between the jaws of the verniers is 5" at zero spring force, the tension in the blade will be 6 ksi for every 0.001" the gap increases as you increase spring force. Record the reading on the dial gage, verniers, as well as turns on the spring as you increase spring force. Based on your comments you likely will get to a point where the reading on the calipers no longer increases but the reading on the dial gage does. Continue to take measurements as you turn the spring adjuster for another turn or two.

Now take your data and plot spring turns on the X-axis, caliper reading on one Y-axis, and dial gage reading on the other. The slope of both lines should increase nearly linearly up to where the value on the calipers stops increasing. Above that point if the dial gage reading stays constant at higher spring turns then the spring is the problem. However, if the slope of the line for the dial gage gets a lot steeper the problem is the frame. Let's hope it's the spring.

John

[JOEL MONGEON]

Interesting discussion. Those pics look like they may be the result of an excessive feed rate. I have used the flutter method (see Suffolk's site) on my Resaw Kings since day one. I cut 1/16" veneer between the blade and the fence using minimal tension. More years ago than I can remember I embraced the method of proper setup and alignment of the saw making your blade really want to cut true. I've been riding that horse ever since ;-) I know there are other methods of making a saw cut along the line you want and if those are working for you, keep doing that. There are always more ways than one to skin the cat.

Hi Glenn, thanks for that reply. It was the first time I'd heard of the flutter method. Thanks I'll give it a try when I'm back in the shop.

[JOEL MONGEON]

Thanks for the detailed reply John, I should have left it at "less tension" instead of "release the tension".

That is a very good idea. I've got a tension meter on order, it should show up in a few days. I'll try and test if the spring is an issue or at the very least find out how much tension I am applying to my blades. In the meantime I'll try out what Glenn mentioned with the flutter method.

[al ladd]

Reading this I see I use an unusual method of murky provenance (as I can find no mention of this particular method online, though others do talk of blade's musical pitch)that has worked great for me for over 30 years, for a variety of blades on my 20" Davis Wells. I pluck the blade like a guitar string as I tension it, listening for the first additional increment of tensioning that stops producing a discernible raise in pitch. I stop there. This is a noticeable discreet point. Then I do the flutter test, releasing tension if I have flutter (which I almost never do). I get great blade life, wheel bearing life, and resaw results. No tools, no math, but I do have to turn the radio off..... I mostly use 1/2" Trimasters, 1/2" Woodslicers (or its competitors), and 1/4" 4 tpi for tight curves. I do a lot of resawing.....