Skew Bevel Again

[windknots]

Jeff - Thanks for the prompt reply but I still have a problem/question.  I don't see how grinding longer on one side using the jig will make the bevel length/angle change if the protrusion length does not change or the universal support moved. I will try to define it in another way.  I'm using to SVS 50 jig and believe the universal support is parallel to the wheel surface. 

If I grind a skew that has a 1/4 inch blade thickness and look down from the top, the "V" cutting edge where the bevels intersect, is not centered 1/8 inch from each blade edge.  It is shifted to the side with the shortest bevel.  I have rounded the blade edges on the skews that were square; however, I have the same problem with factory rounded skews.

I'd like to know what I'm doing wrong before I use up any more steel or return to hand grinding.

[Jeff Farris]

Jeff - Thanks for the prompt reply but I still have a problem/question.  I don't see how grinding longer on one side using the jig will make the bevel length/angle change if the protrusion length does not change or the universal support moved. I will try to define it in another way.  I'm using to SVS 50 jig and believe the universal support is parallel to the wheel surface. 

If I grind a skew that has a 1/4 inch blade thickness and look down from the top, the "V" cutting edge where the bevels intersect, is not centered 1/8 inch from each blade edge.  It is shifted to the side with the shortest bevel.  I have rounded the blade edges on the skews that were square; however, I have the same problem with factory rounded skews.

I'd like to know what I'm doing wrong before I use up any more steel or return to hand grinding.

But, the protrusion has changed.  As you grind the tool, it becomes shorter and shorter, thus altering the bevel angle  (and the protrusion).  If you establish a bevel on one side, then flip the tool over, if your previous grind is such that you're working toward the front edge of the tool, you will be taking length off the tool from the start.  This scenario is most frequently found when first using a jig on a tool that has been freehand ground for a long time.

Having the tool centered in the vee blocks of the jig will insure that the bevel is parallel to the cutting edge. Having the edge centered on the thickness of the skew can only be controlled by monitoring and adjusting the amount of time spent grinding each side.

All that said, if you take a look at the skews in the tool rolls of the world's best turners, I bet you wouldn't find more than a couple that are perfectly centered, and those are probably an accident.    Close is good.  Exact is not necessary.

[windknots]

Thanks Again Jeff !!   I finally got it.  I never thought about the protrusion changing as the tool is ground.