Woodworker's Journal fall-2008, страница 88

Adjustable Shop Horse

ADJUSTABLE HEIGHT MAKES A WORKSHOP STEADY EDDY EVEN MORE PRACTICAL,

by bill hylton

Everyone needs trestles or saw-horses, and I'm certainly no exception. Each pair of my shop horses is slightly different, though all have the same basic design and construction. The first pair I made are about knee-high and 30" wide. The second pair, my ponies, are shin-high and only 24" wide. The third pair — the ones I'll be describing here — are adjustable in height, ranging from 24" up to nearly 35".

My adjustable horses have nesting posts, joined with sliding dovetails. The outer elements are mortised into the trestJe feet. The inner elements are attached to a beam and are joined

to a wide stretcher with crossdowels and connector bolts. The outer elements are similarly joined to a narrow stretcher.

Begin construction with the feet. Each foot is made by glue-laminating two plies (pieces 1 and 2). You cut a half-lap across each piece, and when they are glued up, the laps form a through mortise.

Shaping the Feet

To produce the shape, I routed an instep on each foot blank, then band-sawed the rough contour and template routed to final shape. Only after this work was done did I glue up the feet.

The instep is a simple cut on the router table, but it does take several passes to complete each part Use a 1"-diameter straight bit. Raise it about 7/8", and set the fence so about half the bit is exposed. Clamp stops to the fence to give you starting and ending points for the cut. To limit the amount of material removed on each pass, use a series of removable shims until you are routing right up against the fence. To contour the foot blanks, make a template to which you can clamp the workpieces with toggle clamps. The template need have only the right-hand portion of the overall contour: so when you rout, you are moving from ankle to toe, and the cutting edges are "laying down the grain." That's a clean, problem-free cut. To complete the shape, flip the workpiece over and rout the second half of the blank, again moving from ankle to toe.

Making the Telescoping Uprights

The uprights (pieces 3 and 4) are made up of two pieces, joined with a

Using an edge guide to position the shallow dado in the beam ensures that all four cuts will be the same distance trom the ends. The damp secures a stop block.

Template-rout the contour of the foot plies. The author's template has locking clamps to immobilize the workpiece.

88 ADJUSTABLE SHOP HORSE "

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