Onsrud Tech Page

[coach]

www.multicamnw.com/support/manual/onsrud_routing_guide.pdf (http://www.multicamnw.com/support/manual/onsrud_routing_guide.pdf)

I came across this the other day.
I found it helpful.

David

[john_hartman]

Thanks for posting this. I just skimmed through it and I can tell its going to answer all sorts of questions!

[nick]

Excellent post. I love the technical aspect of cutting technology.

[scottbot]

Thanks David.
Just when I thought the learning curve was starting to level out...

Scott

[rhfurniture]

I have to say that there is one thing that has totally mystified me for the whole of my woodworking life.
There is in this pdf (page 15) a chart that defines "wood cutting angles" for different species of hardwood. There is then a little diagram that defines "rake angle", "wedge angle", and "clearance angle" with ABSOLUTELY NO mention of the "wood cutting angle". Would somebody kindly put me out of my misery and explain in terms of simple geometry what is the "wood cutting angle" ?
Thanks,
R.

[harold_weber]

See page 264 of Hoadley's "Understanding Wood".

He says that the angle between the face of a cutting tool and a plane perpendicular to its cutting direction is called one of the following:
>Cutting angle
>Chip angle
>Hook Angle
>Rake Angle
>Angle of Attack

This agrees with the little diagram in the Onsrud Publications

[rhfurniture]

Thanks Harold, that was what I tended to assume. I was confused by the diagram which showed a rake/cutting angle of around 50 - 60 deg which was no where near the figures in the chart, more like my little hand block plane. The figure on p6 of the pdf is a little more like it. Most machine cutting angles seem to be in the 15 - 25 deg range. I remember when I was planing a lot of curly grained hardwood I had a 10 deg bevel taken off the front of the planer knife and this helped. Does anyone have a definitive chart of the different cutting angles for different materials, ally, plastics, mdf, softwoods, etc ?
Anyway thanks for the clarification, I shall be confused no more.
R.

[don]

I used to work at a shop where we manufactured and reground tooling for the automotive and medical companys.
This link is to a pdf file that Weldon Tools (http://www.endmills.com/catalogs/weldon/Weldon1998.pdf) put out many years ago.
Tons of information (geared toward tooling used for cutting metal)
Between Page 109 and Page 114 of the pdf file shows and explains the tool geometry of an endmill and the terminology stands true with any cutting tool.
The regrind shops can add, decrease, alter any geometry to make the tool like new again.

Don