Cutterhead Knife Mark Calculator

 

Instructions
On the lumber to be analyzed use a ruler to measure the distance between the knife marks. 
In order to see the knife marks more clearly highlight the knife mark cusps by rubbing the material sideways with a piece of chalk or a carbon stick.  Mark eleven knife marks and measure the distance between the first and last mark.  Divide this measurement by ten to get an average of inches per knife mark.

On the knife mark calculator chart draw a line between the Feed Speed and the Number of Knives for your machine.  This line will cross the center line at the corresponding Inches per Knife Mark / Knife Marks per Inch with all knives active in the cut.

Example Below

Speed = 180 FPM

Number of Knives in Head = 6

Knife Marks per Inch = 10

 Click here for a printable
version of the Knife Mark
 Calculator

Planing Guidelines:   (Typical Knife Mark Requirements)

 

Hardwood Planing
Rough Mill Planing - 7 to 8 knife marks per inch

Finish Surfacing - 15 to 25 marks per inch

 

Softwood Planing
Planer Mill - 3 to 4 knife marks per inch
Dimension (Finished Boards) - 8 to 10 knife marks per inch
 

Newman Machine Company, Inc., 507 Jackson Street, Greensboro NC  27403
Voice: 336-273-8261 Fax: 336-273-6939 sales@newmanwhitney.com

Copyright © 2005 Newman Machine Company, Inc.  All Rights Reserved.