How many of you roll your blades when you sharpen them? Do you think it helps? Ricky
I don't sharpen my own blades, but the guy that I just started using is very meticulous about his blades. He checks each one and rolls the ones that need it. Don't ask me how he decides which ones need rolling. I can give you his contact info in a PM if you'd like. I know he'd be more than happy to discuss the topic with you.
Quote from: Ga Mtn Man on March 03, 2013, 07:39:22 PM
I don't sharpen my own blades, but the guy that I just started using is very meticulous about his blades.
What I was trying to say is that he treats every blade as if it were
his blade. :)
Whether it helps depends on the type of band wheel. Some bandwheels are worse than others about bending the blade. You can put a steel straight edge across the blade and look for any crosswise bending. My experience is that it helps. Like GA Mtn Man, I send my blades out for sharpening, and they get rolled if they need them. Been very satisfied, but don't have anything else to compare them to.
I've gotton along a long time with no roller with 1-1/4 blades, I think they benifit 1-1/2 + blades more. Steve
I believe you're right Steve!
I use the 1¼ inch WM Double Hards and have never had a problem relative to blade rolling!
Whats a sign they need rolling?
The straight edge trick the easy way to tell?
Cheers
Justin
All this rolling talk, can someone show me who sells a band roller? ::) Among its uses, it would be good for quickly fixing over-set bands.
Cook Saw sells them and swears by them, for all size bands (even 1.25 inchers) and all wheels, tired and crowned. Ask them for a video. The roller won't correct for overset. It's non-intuitive how it works; a ball-shaped roller contacts one side of the blade - not sure about the contact for the other side.
I have checked my bands w/ a straight edge and have seen a crack of light indicating curvature but I have also seen the same crack on new bands (Simonds Red Streak) right out of the box. ??? I don't roll my bands but would love to try it to see if it corrects the slight rising in the cut I experience.
Bob
My neighbor has a gadget, nogt a band roller that I think he got from WM which takes the set out of over set blades.
I have used it on occasion and it works well.
I am wondering if rolling is only necessary when using crowned wheels?
Pete
I've used an english wheel to take the set out of a couple of blades that had hit rocks with good results.
In simple terms, can someone explain what you are talking about/issue? I'm thinking you are referring to an unequal lengthening of the blade during its life. Somehow you can "roll" (squish it to make it longer) one edge to make it "straight" again?
A blade roller flattens the band.
It is run lengthwise of the band.
Using a straight edge, lay it on the band front to back, if you see an air gap under the straight edge, the band would then be rolled.
Here's some good info on the subject:
http://www.cookssaw.com/sawmill-blade-insight/understanding-blade-flatness.html
Ok, so the band developes a cup, conforming to the crown of the band wheel, right? That could mess up the cutting abality!
To check if the blade needs rolled I use a utility knife and place it across the blade. If there is daylight in the middle or on the ends of the blade it needs to be rolled. What causes the blade to cup in the middle of the blade is the fact that everything you do to or with that blade is done to the leading edge of the blade. Over time it will make the leading edge of the blade a little longer than the back of the blade. Rolling of the blade will elongate the back edge of the blade thus making it flat.
Most of my blades are 1¾" and it is rare that I have one that needs rolled. I do run my blades longer than most so 3-4 sharpening is all I normally get. If I do get a blade that gives me trouble and everything else is right then I check the flatness of the blade.
There were a few post made while I was pecking out on the putter.
customsawyer
I wish that explanation made sense to me, but it doesn't add up to a blade that has a hump across its width (and that hump is what we are hearing is the problem).
But I'll sit tight until something comes along that does explain (to me) what rolling does to remove that hump across the width. ;) And I may just be too dense to ever understand it, so don't distress over my problem.
Quote from: ljohnsaw on March 06, 2013, 07:26:51 PM
Ok, so the band developes a cup, conforming to the crown of the band wheel, right? That could mess up the cutting abality!
It's counter intuitive, but it actually develops a cup away from the band wheel crown. Take one of your bands and bend a curve in it about the diameter of your band wheels and check the blade for flatness on the curved portion. You'll see the concavity on the outside of the band.
Beenthere I feel your pain. It took me along time to understand how it worked and what was happening.
I will try to explain it another way. In the process of cutting with and sharpening your blades the blade becomes a fraction of a thousandth longer between each tooth. When you add that fraction of a thousandth up over 210 teeth, on my blades, it makes the leading edge of the blade a few thousandth of a inch longer then the back edge of the blade. This is what causes the cupping of the blade. When rolling the blade you adjust it to where the roller is making contact on the back 1/3 of the blade. The best picture of how it works for me is imagine a blacksmith with a narrow piece of metal on their anvil. As he hammers it and moves it along his anvil it will slowly get longer. While the roller has no hammering effect it has the same concentrated compression effect as the hammering. I hope this helps to make it clear as mud. ;D
Custom,
Thanks. I totally understand what you are saying. Now a question: do you notice this growth in the leading edge as a function of using the blade (cutting, heat buildup from the cut or bending around the wheels) or from the sharpening/setting process? Just curious. Also, as a matter of practice, do you check every blade before use (including new), before sharpening or just when an issue rears up?
I have done lots of checking of blades both new and used. I have found that almost all blades have at least a small amount of cupping. The more it is used the more cupping will develop. I have found that I get the best results not worrying about it till a problem arises.
Keep in mind that I am not a scientific type in any stretch of the word but my feeling is that the increase in length to the leading edge of the blade comes mostly from cutting.