TGTool
Titanium
- Joined
- Sep 22, 2006
- Location
- Stillwater, Oklahoma
This has been a recent project, partly of need and partly for fun.
Some time back I'd seen a couple intriguing photos in the Moore book "Holes, Contours and Surfaces". They were demonstrating how to check squareness by reversal with appropriate shots. And I give them particular credit for starting by pointing out that the blade of the square must be verified as flat and parallel before the squareness reversal check can mean anything. Not all the subsequent commentators and Youtube creators include that necessity.
So here are the shots from the Moore book.
Looking at the photo, it's clear that the square he's working with was shop made. A cast iron beam, nicely scraped and frosted, and probably a hardened and ground beam. This suggested a good tool and an interesting project. What I teased out of the photo is that the blade is carried in a secondary holder, and you can just discern two holes in the top edge of the beam that must be for adjustment. That is, the blade carrier is designed to pivot over a small angle and the squareness can be adjusted and set.
So this is my shop version.
I think the only feature I don't yet have is that lump along the middle of the blade. I puzzled about that for a time, but I'm confident now that it's a small stub on each side so that when the square is lying flat on a surface the blade is supported. Otherwise if will just fall, as this does, unless the beam is clamped square to a machine surface.
Some time back I'd seen a couple intriguing photos in the Moore book "Holes, Contours and Surfaces". They were demonstrating how to check squareness by reversal with appropriate shots. And I give them particular credit for starting by pointing out that the blade of the square must be verified as flat and parallel before the squareness reversal check can mean anything. Not all the subsequent commentators and Youtube creators include that necessity.
So here are the shots from the Moore book.
Looking at the photo, it's clear that the square he's working with was shop made. A cast iron beam, nicely scraped and frosted, and probably a hardened and ground beam. This suggested a good tool and an interesting project. What I teased out of the photo is that the blade is carried in a secondary holder, and you can just discern two holes in the top edge of the beam that must be for adjustment. That is, the blade carrier is designed to pivot over a small angle and the squareness can be adjusted and set.
So this is my shop version.
I think the only feature I don't yet have is that lump along the middle of the blade. I puzzled about that for a time, but I'm confident now that it's a small stub on each side so that when the square is lying flat on a surface the blade is supported. Otherwise if will just fall, as this does, unless the beam is clamped square to a machine surface.