Fred Rowe
Well-Known Member
Progressive grinding for the perfect flat grind.
Grinding the bevels on a blade, while changing the angles of approach or Progressive grinding. There are several benefits to this method.
I used a 4 inch by 2 1/4inch by 5/16 inch section of planer blade for this demonstration.
The first picture shows the blade section, end on, before it was ground.
The second and third pics show a 10 degree grind on the left side of the blade.
The forth picture shows the results of switching to a 5 degree angle of approach. The grind moves up the blade and moves to intersect the edge that was ground at ten degrees.
This next picture shows the grind at 4 degrees angle of approach, the grind moves up the blade and moves to intersect the edge.
I jumped from a 4 degree angle to an angle of 2 1/2 degrees to show the amount of grind line change caused by changing the angle of approach by 1 1/2 degrees.
The last picture shows the grind at the 21/2 degree grinding angle.
As you can see the grind has gone completely across the 21/4 inch blade section.
The straight edge shows the ground side to be perfectly flat across the flat.
When you grind blades by degrees, two things will happen, one is the grind goes faster because you are grinding across the high points left by the previous angle of approach. The second is you will end up with a perfectly flat bevel.
Happy grinding, Fred
Grinding the bevels on a blade, while changing the angles of approach or Progressive grinding. There are several benefits to this method.
I used a 4 inch by 2 1/4inch by 5/16 inch section of planer blade for this demonstration.
The first picture shows the blade section, end on, before it was ground.

The second and third pics show a 10 degree grind on the left side of the blade.


The forth picture shows the results of switching to a 5 degree angle of approach. The grind moves up the blade and moves to intersect the edge that was ground at ten degrees.

This next picture shows the grind at 4 degrees angle of approach, the grind moves up the blade and moves to intersect the edge.

I jumped from a 4 degree angle to an angle of 2 1/2 degrees to show the amount of grind line change caused by changing the angle of approach by 1 1/2 degrees.
The last picture shows the grind at the 21/2 degree grinding angle.
As you can see the grind has gone completely across the 21/4 inch blade section.


When you grind blades by degrees, two things will happen, one is the grind goes faster because you are grinding across the high points left by the previous angle of approach. The second is you will end up with a perfectly flat bevel.
Happy grinding, Fred
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