Tension setting for those with 'economy' mills

[Gilman]

Jim,
The nice thing about strain is that it doesn't care or know the difference.  You can use this method with goat hair wheels if that's what your running your blades on.

You're very welcome Highpockets

[highpockets]

Lennox replied to my question and said 0.0025" on 5" test. 

[brucehuggins]

I pluck it with my wrench and listen for the thrum.m.m.

Works as good as anything else I have tried.  I borrowed a tension meter from my blade source but broke blades when jacking it up to the recommended tension.  I have tried keeping track with a torque wrench too. 
I can cut flat lumber without those  things but there was a learning curve.  A lot of broken blades and wavy lumber due to improper tension at first. 

[highpockets]

I think the proof is in the pudding.  I am still a little confused in what I read and what little I can calculate. Ken told me that he had a 1" cylinder on the WM Mill tensioner.  I think they recommend some  2,000 p.s.i. of pressure.  To me this calculates to some 1680 (calulator not handy) lbs of force on the shaft. If you divide that by two, I don't see where the 15,000 lbs of (Lennox recommendation) strain come from.

To be honest, I started out trying to run by these large numbers. I broke probably 30% of my blades. Since I started pulling the flutter out and tighten a little, I can cut good woood and have not broken a blade out the last 14.   

[Lud]

I agree with Brucehuggins.  I would pluck the blade on my vertical bandsaw and you could hear a note.  Do it enough times and you'd know when you were getting tight enough.

I'll try it on the mill whenever it stops working perfectly!  :D :D :D

[Gilman]

High Pockets,
I think Lennox was referring to pressure lbs/in^2 the band experiences, not lbs of pull.

Assuming you have 1 1/4" blades x 0.045" thick and 1680 lbs of pull

pressure (stress) = (1860lbs/2)/(1.25" x 0.045") = 14933 lbs/in^2 (psi)

[highpockets]

Gilman, I am certainly glad you are around.  I am getting old and my thinking does not seem to be what is used to be.  That sounds about right, now you mention it. 

[Russ]

I had alot of problems at first with blade tension on my mill. I now put 48-50ft lbs on the bolt with a torque wrench. If you have to keep tightning its because  your blade is hot and stretching because its dull. If you don't sharpen the blade its going to start cracking. I debark and use keosene for lube, this helps my blades run cooler, don't use much, if your blade hydroplanes bad news.  Kerosene will ruin the tires on some mills. I have much better luck with my blades now.

[ADebMallick]

How we can find out tension in  a circular saw 10 mm Thick 1500 mm diaby A STRAUGHT EDGE WHICH HAVE
A ROUND BOTTOM???

What is this straight edge for?



For thinner saws you can use ALLEN GAUGE.

[beenthere]

Wonder what note on the scale the blade will give when plucked at the right tension?  If that is what it takes, seems that with a pitch pipe, blade tension could be 'tuned' to the correct note.  Anyone know what that note might be?  Any violinists on the forum?  or maybe even a trombonist  ;D or string plucker :