Editor’s be aware: William Howes’s Ames square is without doubt one of the shop-made instruments featured in our gallery for Tools & Shops 2022. Here, he particulars how he made it.
Nathan Ames of Boston was issued a patent in 1852 for a square that might be used to discover the middle of a circle, a useful gizmo in setup for spindle turning on the lathe. This ingenious device was manufactured by J.R.Brown and Sharp of Providence, R. I., and is typically nonetheless obtainable in outdated device markets. Ames held different patents together with one for a precursor of the escalator.
As nicely as discovering the middle of the inventory, it will also be utilized in a vogue like a contemporary velocity square to structure 90° and 45° angles and to examine inside corners for squares. I made a decision to reproduce this enticing device in wooden.
Creating a duplicate in wooden requires cautious work, and after a number of makes an attempt, I concluded that the usage of easy jigs would enhance accuracy.
Start by milling inventory to 5/eight in. by 5/eight in. Any fine-grained hardwood is appropriate, I’ve used apple, hawthorn, and beech, however something obtainable will work.
Join the square sides with a butt joint held by a screw (1 in.#6). A jig to maintain the items at 90° is beneficial.
Alternately, a half lap joint includes no screw, and if the glue-up is true the joint stays square, in distinction to the butt joint.
The base or hypotenuse of the triangle joins the 2 equal sides with half-lap joints. Lay these out to a depth of half the thickness of the ruler. I made my rule 1/four in. thick, and the lap joint mortises every 1/eight in. deep. The blue tape helps with the accuracy.
And a flush-cut noticed with no set permits the positive minimize.
Again, a jig to maintain every little thing square throughout glue-up simplified issues.
Setting the ruler in.
A small scrap minimize to 45° aids in laying out the mortise for the ruler. Measure from each edges and go away the road, as this would be the future heart line that you find yourself drawing once you use the device.
Take care with the structure, ensuring that the ruler is to the left of the midline, if you’re right-handed.
Remembering that this view is of the underside of the square, make the inset for the ruler a hair undersize in order that adjustment might be made to permit the ruler to be 90° to the baseline.
Before gluing up, it’s simpler to soften the perimeters and corners.
The completed product.