Sawmill Design
Contents
Overview
Sawmill Design
Design
Z Height Leveling
- Turnbuckle attached to upper z adjustment peg
Evenness of Z Height Raising Along 4 Posts
- Build 4 inch winch drum - each revolution winds 1' of wire
Log Taper Adjustment
- Disconnect mechanism for connecting rod between front and rear z-risers to create a height differential between the two ends of the log
Edger
- Adjustable from 1-3 blades in standard version, up to 6 for 6 2x2 lumbers in one pass
- In 3-blade configuration, top edger blade is controlled by a crank that can be adjusted while sawmill is running
Gantry
- Box truss design
Carriage'
- Clearance of 1/8" around gantry
Hydraulic Hoses
- 4 Hoses
- Mast at either end
Trailer Hitch
- Telescoping piece of tubing in frame
- Hitch retracts for sawmill operation
General
- Counterweight for hydraulic motor on one side of gantry - balancing
- Saw and collar - typically from same manufacturer
Vertical Motion
- One crank with a worm gear controls one side, connected to second side via connecting rod
- Vertical adjustment - 4 worm gear sets - [1]
- Bronze bushings - for vertical adjustments
Horizontal Motion - Crosswise
- Crank with indicator
- Sprocket with chain to another sprocket with pinion, riding on rack
- Rack faces down
- Sprocket and pinion sheltered from dust
- Connecting rod connects to other end
- Link rod contains a telescoping slip joint with pin, to retain of modularity of track lengths
Horizontal Motion - Lengthwise
- Festooned hydraulic hose
- Hydraulic motor rides under the gantry
- Engine moves carriage via a spool over which a wire is wrapped
Horizontal Dimension
- Set by guides that are rolled out with a single crank
Automatic Feed
- Separate hydraulic motor - with a riding bidirectional valve that trips its lever to other dimesion upon reaching end of track
- Wire drives carriage
- Have a safety trip in case of running into metal objects in wood
Dust Ejector
- On top of blade guard
Set Works
- Set relationship of saw to the log to make the next cut
- Dimensional sawmill needs setting in 2 dimensions
Log Holding
- 2-stage dogs - one for staring the log (high center of gravity), and second for low center of gravity
- May want to flip log if it's difficult to hold towards the end
Outstanding Design Issues
- Hydraulic hose cabling guide
- Multiple edger blades in future
- Crank edger adjuster
Action Points
- Saw collar
Design
CAD
Materials Sourcing
- [10] 3/4" bearings for rollers on top of gantry- [2]
- Cam followers - 4x the cost - [3]
- [4] V-groove bearing for x (transverse) direction motion on inverted angle- [4]
- [4] 2-bolt, 1/2" flange bearing for y (lengthwise) motion - for pinion gear shaft
- Rack - 8' - [5]
- [2] Main shaft pillow block bearings, 1-7/8" - [6]
- [2] Secondary blade pillow block bearings - [7]
Fabrication
Blade
- Anneal blade to machine
- Harden blade by heating and quenching
- Surface grind to flatness
Dogs
- 1.25" square bar, sharpened to a 45 deg angle
Log Handling
- CAT 966 was industry standard for large sawmills; largest logs are 14000 lb
- John Deere 450 bulldozer - entry level, handy tool
- Yale lift
Documentation
- Z raising mechanism: worm gear for 4 posts, with adjustable wire tension
- Y axis - transverse motion - gear rack with chain linkage
