Replies

1. 
   SARGEgrinder47 | Feb 15, 2010 04:17pm | #1

   Turn the machine on after you have set tension and tracked by turning the upper wheel by hand with it off.. place a small sharpening stone on the table behind and simply move it in an arc on the back edges.

1. 
   RalphBarker | Feb 15, 2010 06:52pm | #3

   Doesn't Festool sell a
   Doesn't Festool sell a machine that does this for $695? ;-)

2. 
   Rich14 | Feb 15, 2010 05:24pm | #2

   Quickstep,
   Since you're
   Quickstep,

   Since you're asking this question, I'm going to assume you have no experience doing this. So I'm going to ask, why do you want to do it?

   Have you read or heard this is a good thing to do to a band saw blade?

   I've seen this practice advocated in band saw books and have come across it occasionally repeated in wood working forums. I think it falls in the category of something that someone advised to do some time in the past, seems like a logical thing to do ("it makes it easier to cut tight curves") and just gets repeated in books and lore.

   In my humble opinion and many years of using band saws, I have never found any usefulness in rounding the backs of band saw blades. In fact, if it made blades cut better, some manufacturer would offer it as an "improvement" over his competition. But I'm not aware of any brands that are available "pre-rounded."

   Cutting curves on a band saw requires proper technique and the blade size matched to the range of radii that you need to cut. I don't think that rounding the back of the blade will improve performance.

   That said, you can do the job using a small stone held on the table. Protect the table with a sheet of paper if you don't want the stone to scratch it.

   Let us know if you can detect any change in the blade's performance.

   Rich

3. 
   philip | Feb 15, 2010 10:50pm | #4

   Sarge has described a practical way of doing it, and you can use any stone like a grinding wheel or part of, or a dressing stone, when the machine is running . I often use a die grinder, or a Dremel can be used.

   I have found that rounding the back is beneficial in that

   1) it prevents hang ups when one needs to back out especially on a curve- yes, yes bad practice but in practice things often turn out differently to the theory- and you have to back out.

   2)Blades last longer- I should know because I use my bandsaw(s) to cut various materials including brass and tool steels. Stress cracks develop on sharp corners.

   3)Blades which have been electrically butt welded often have a weld bulge seam at the rear due to the pressure exerted when the butt welder clamps press the ends together so one needs to fair that off and one might as well round the back off at the same time-hence the die grinder being the fastest method.

   4)There will be times when it is necessary to take tighter curves than the blade would like-if the back is rounded this will be easier to do.

   I don't think it is a counter productive practice at all.

1. 
   SARGEgrinder47 | Feb 16, 2010 10:29am | #6

   Ditto Phillip on all counts. It simply makes common sense to me that a square corner dragging in a curve is going to produce more friction than a rounded one. More friction.. more heat and heat is very critical to carbon style blades used in curve cutting.

   Never thought of the advantage Phillip mentioned when backing out of a cut. But.. you probably don't use a BS much for curve cutting.. tenons.. dovetail waste removal if you have never encounted a situation you didn't "have" to back out of a cut. Maybe in cyber-world but not in the real one IMO. ha.. ha...

4. 
   Quickstep | Feb 16, 2010 09:55am | #5

   I've been using my bandsaw
   I've been using my bandsaw for about 25 years and have never rounded the back of the blade. I've read about it as a method to get more relief behind blades, especially small ones which have only a small amount of set in the teeth. I never really thought about doing it, but recently while buying a new 3/16" blade a guy I respect (and ironically the guy from the machinery store where I originally bought the saw new), suggested it.

5. 
   Jammersix | Feb 16, 2010 10:33am | #7

   Don't bother, no payoff.
   Don't bother, no payoff.

6. 
   Quickstep | Feb 16, 2010 08:03pm | #8

   I never thought of the backing out thing. Makes sense though since 90% of my bandsaw cuts are curves and my poor planning skills mean I often have to back out of a cut. Makes me wonder why the manufacturers don't make them that way to begin with.

1. 
   philip | Feb 17, 2010 11:27pm | #9

   Manufacturers of certain metal cutting blades DO  round the backs off- to reduce metal stress. I don't know of any wood cutting blades made this way by the manufacturer and do doubt if they do it- costs a bit more and the customer can do it easily anyway. Wood cutting stuff tends to be made on a shoe string budget  due to the nature of the end user (!) and  for the same reason you could wonder why the average wood cutting blade is not as sharp and well set as it can be if re-sharpened by a dedicated sharpening shop.....