Sawmill - Design Rationale

Things the sawmill must be able to do. See Sawmill Analysis for calculations based on these requirements.


 * Must adhere to OSE Specifications. (Open documentation. Low cost and easy to manufacture/replicate. Design for life, disassembly, repair. Robust, multipurpose.)


 * Must be able to cut about 2400-3000 linear feet of dimensional lumber per day.


 * Must handle up to 3000 lb logs.


 * Must cut 4x4s and flat 2x of large width.


 * saw wobble specification 1/16"

Motor Rationale

 * Must use hydraulic power from LifeTrac.


 * Power is about 40 hp - available from 55 hp Deutz, at .72 system efficiency.


 * Hydraulic motors utilize 24 gpm at up to 3600 PSI. Each motor is 40 hp, around 700 RPM.


 * 2 Cushion valves are used for stopping in bidirectional configuration.


 * 2 spool control valve needs to handle the full fluid flow (24 gpm) to each motor.

motors, from full power in one to full power in the other.
 * To use power effectively, one should be able to control the amount of flow to each of the two


 * Main blade RPM - 2000 RPM.
 * Edger blades - 5000 RPM.
 * Simple pulley system, with single pulley of 3x for main blade.
 * Double pulley for edger blades, about 2.5 ratio for each.

Platform Function Rationale

 * Needs a platform that will be able to hold the weight of the motors, pulley system, blades, and frame.
 * The weight of the platform will be about 25 lb. per motor, etc for a total of about 200 lbs.
 * The platform must be stable enough to make straight cuts.
 * The platform should be able to roll in the x axis.
 * The platform must move precisely and hold securely in the y and z axes.
 * The y and z axis movements must be about 3-4 feet for large logs.

Function List

 * blades with insert teeth would be best to use, but maybe expensive
 * 2 edger blades on same axle
 * 2 edger blades are adjustable
 * Move onto hydraulic log handling later
 * Move on to automatic sawmill operation with remote control, for ease of cutting.
 * Allow for log turning in addition to taking slices out of the wood
 * Safety cage around blades
 * Blade cooling soapy water?
 * Logs loaded with tractor loader
 * Mechanism to secure log to track
 * use bearings to ride on a flat track?