shaper cutterhead questions....

[Warren Lake]

works for me I could not get it but knew its further so how? thought it hangs out more then no thats not right but if you do what you say brent visualze the tilt then top and bottom are further from the bore it becomes clear still odd though.

[Imran Malik]

It becomes even easier to visualize if one thinks in terms of circle of cut. So take a top view of the cutter head. Straight knife, as Brent said, there is a single circle of cut. Now start rotating the knife around the middle. The top view will clearly show that the leading and trailing edges of the knife are leaving the original cutting circle and creating a larger cutting circle. This becomes even more obvious when the knife is rotated to 90 deg from vertical. The circle of cut made by the leading and trailing edges of the knife is much larger than the middle. Therefore, the cut from a shearing rebate head will always be more at top and bottom vs the middle.

[brent stanley]

It becomes even easier to visualize if one thinks in terms of circle of cut. So take a top view of the cutter head. Straight knife, as Brent said, there is a single circle of cut. Now start rotating the knife around the middle. The top view will clearly show that the leading and trailing edges of the knife are leaving the original cutting circle and creating a larger cutting circle. This becomes even more obvious when the knife is rotated to 90 deg from vertical. The circle of cut made by the leading and trailing edges of the knife is much larger than the middle. Therefore, the cut from a shearing rebate head will always be more at top and bottom vs the middle.

Yup, saying the same thing a different way. This is why the shear cutting, segmented heads have a radius on the little carbide inserts to compensate for that. Byrd uses the same inserts all the time for all their heads but if the head is a different diameter and other elements of the geometry are different, the compensation offered by the radiused head will not necessarily be enough. That's why performance (in terms of the scalloped surface) is not the same for all Byrd heads.

[brent stanley]

I got a lot of questions about it and decides to do a little video on the subject:

https://youtu.be/-kaS1iLAqS4?si=1iyl08l05wZiGxtm

B