Skew the Plane, Lower the Cutting Angle

[MarkSLSmith]

Folks, 

I've always had difficulty visualizing this, so I made a video that I think shows it very clearly.  Enjoy!

https://youtu.be/Zya6BSlDh-A

Mark

[Handplanesandmore]

A very clever way of explaining the subject. Maybe someone has done it before, but yours is the first time I saw a demo. like that.

Another way to show the lower angle is to plane a tough grain surface without skewing and then with skewing. See the difference in the degree of tearout.

Simon

[Timberwolf]

A very clever way of explaining the subject. Maybe someone has done it before, but yours is the first time I saw a demo. like that.

Another way to show the lower angle is to plane a tough grain surface without skewing and then with skewing. See the difference in the degree of tearout.

Simon

....................
A very clever way of explaining the subject

I agree...first time I have been able to "picture" that in my mind, even tho I have thought about it.

IMO, one of the main reasons the cut is smoother and the plane is easier to push is the fact that when skewed, the cut is a "slicing" action...as opposed to only a straight "pushing" action. You can demonstrate this by sharpening a knife blade and cutting a sheet of paper..make one cut pushing the blade straight down {no slicing}, then make another cut pushing down with a slicing action. You can also do this cutting a ham or a turkey.."slicing cuts" make the blade "perform" like it was sharper because under high magnification, the edge of any sharp blade has very fine "saw teeth" and when skewed it behaves just like a saw and puts more "teeth" into contact with the work to be cut.....

[MauleSkinner]

This is also why jet planes have swept wings.

[Pedder]

I will never get, if the slicing is more than lowering the cutting angle.
If you just push it skewed but straight forward, there ist no action of microteeth like in sawing.

[MarkSLSmith]

....................
A very clever way of explaining the subject

I agree...first time I have been able to "picture" that in my mind, even tho I have thought about it.

IMO, one of the main reasons the cut is smoother and the plane is easier to push is the fact that when skewed, the cut is a "slicing" action...as opposed to only a straight "pushing" action. You can demonstrate this by sharpening a knife blade and cutting a sheet of paper..make one cut pushing the blade straight down {no slicing}, then make another cut pushing down with a slicing action. You can also do this cutting a ham or a turkey.."slicing cuts" make the blade "perform" like it was sharper because under high magnification, the edge of any sharp blade has very fine "saw teeth" and when skewed it behaves just like a saw and puts more "teeth" into contact with the work to be cut.....

 
Agreed!  I commented there were a variety of reasons, and the slicing action may even be the primary reason.  But I always had trouble visualizing the "lower angle" thing, and now I have settled that question in my mind.

Mark

[Timberwolf]

 
Agreed!  I commented there were a variety of reasons, and the slicing action may even be the primary reason.  But I always had trouble visualizing the "lower angle" thing, and now I have settled that question in my mind.

Mark

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But I always had trouble visualizing the "lower angle" thing, and now I have settled that question in my mind.

It pretty well nails it for me also...

[Timberwolf]

 
Agreed!  I commented there were a variety of reasons, and the slicing action may even be the primary reason.  But I always had trouble visualizing the "lower angle" thing, and now I have settled that question in my mind.

Mark

..............
Here's a little more on the science of slicing vs push cutting...

https://scienceofsharp.com/2021/04/27/the-slice-cut/

[bandit571]

Usual way for me.    Plane sits at a 45 degree angle to the direction of travel....but the direction of travel is still straight ahead.    And, the sliced shavings simply curl out the side, almost like a spill plane's...

Being right handed, seems easier to have the nose of the plane "pointing" to the left....easier to push that way....

Self-taught that way...just seemed the easier way to plane a flat surface.   Like, instead of trying to peel a layer of a knot in Aromatic Red Cedar....by going full speed ahead...skew the plane and slice the knot.   By the time the knot realizes what happened, you are already by.....and heading for the next knot...

[Tapper]

Folks, 

I've always had difficulty visualizing this, so I made a video that I think shows it very clearly.  Enjoy!

https://youtu.be/Zya6BSlDh-A

Mark

Excellent video Mark - thanks for posting!

Doug