Sawmill - Design Rationale
From Open Source Ecology
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"
- 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.
- To use power effectively, one should be able to control the amount of flow to each of the two
motors, from full power in one to full power in the other.
- Main blade RPM - 1500 RPM.
- Edger blades - 3500 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.
- 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?
Log Holding and Blade Direction
- The blade must spin into the product and into the table or stops or whatever is holding the substrate being worked. Otherwise we make missiles.