Wood milling forces

[mikycampo]

Dear all,

I need to check stresses in a wood milling machine. I search on my books but I've data only for steel as milled material.
I'd use the following formula to compute tangential forces acting in the milling cutter:

FT = ksm * (va/(z*n)) * sqrt(p/D) * B

where

va: cutter/piece advancing velocity
z: teeth number
n: rpm
p: cutting depth
D: cutter diameter
B: cutter thickness

I don't know the value to give to ksm for the wood.
For steel, ksm is such as 5 kN/mm2.

Thanks again Michele

 

[tomwalz]

Are you looking for something like shaft deflection in an overhead router?

This is the way I read it. How close am I?
Force = material strength (tensile strength?) x (linear velocity /(tooth count x rpm)) x (square root?) of (cutting depth / cutter diameter) x cutter thickness

Or the force required depends on the resistance of the material by the feed rate by the size of the bite.

The force required also depends heavily on tool sharpness (sometimes measured by edge radius) and the tool tip material.

There are some wood strengths at:

http://www.woodbin.com/ref/wood/strength_table.htm

Tom


Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

 

[John2004]

The wood handbook (wood as an engineering material) can be downloaded for free from the Forest products Laboratory site...

http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr113/fplgtr113.htm

You can download specific chapaters or go to the bottom right of the page and download the whole book. There is a wealth of engineering information about wood in this book.