Sawmill/Research Development

Goals

An Appropriate Scale GVCS worthy Sawmill with a modular design that integrates cleanly with GVCS equipment.

• Mobile Dimension Sawmill forms a good benchmark for the Industry Standard to start with. As the design progresses, it is expected to diverge radically from the initial prototype. Separation of the power unit, hydraulic power, 3D scanning capability and autonomous functionality are options being explored for later designs.

Design Notes and Rationale

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

Subject Matter Expert Review

The Mobile Dimension saw (MDS) is a serious unit, and well designed. One of the guys on the board of the woods coop has one, though I don't think he is using it or even really broke it in yet. The alignment issue for these saws has been addressed in two ways by them, and more options are up to you. With the Lucas mill, all options are available, just think them up and incorporate them on site, less good. I like the MDS lots, it is all they say it is, I think it works best with large logs.

I think a band mill like a wood mizer, or a shop made unit like the "Procut mobile sawmill" (have plans), or the Mobile Dimension will all work well and it all comes down to the sowyer and the logs. Who runs it? What do your logs look like, What species are they? This sort of thing has to be a bit of a passion to do it right or even acceptably well. This is only a step in the process remember and it is a stairway. Your lifetrack will be well tested in this task.

I would say that if you want to build a mill the plans for the Procut will accomidate chainsaw or band head, a circular saw, multiple saws, or anything else you want to fit in, the plans are $50 from allen at Procut. procut@telus.net These are simple plans, well laid out, and I think they would fit your current style of "open bootstrap", this is an open mill. The basic design costs a tiny bit, then you do anything you want with it.

Benjamen Hansen, Sawyer, Wisconsin, USA

Comments

1. Use a platform with endstands - need vertical and horizontal alignment
2. Track is extendable in modular sections

Design

CAD

• http://openpario.mime.oregonstate.edu/projects/osusawmill/documents

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

=See Also