Shop Made Square

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.

TGTool said:

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.
View attachment 326044
View attachment 326041

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.

View attachment 326042

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.

Click to expand...

I made these...



dee
;-D

dcsipo said:

I made these...

View attachment 326056View attachment 326057

dee
;-D

Click to expand...

Nice tools. And a dovetail.


I've got one too, that's a section of angle plate with one rib. I think there's an underutilized resource in the cheap angle plates from Asian foundries. You may not be able to count on them in the as-received condition, but you can scrape them into accuracy (good practice) or cut them up and make them into other things.

The cut-off square I have is the left over from another project. I didn't bring the edges into square, as you have, thinking there wasn't much application for those sides, but again, it would have been good practice in scraping and in bringing geometry into correct relationship with the attendant choices of which surfaces you scrape in sequence. If you have to true one face to others I'd generally keep the primary references as the ones with the largest area so you have less material to remove on the others.

Here's one I made. Rereading the page now, there are many details I should have included.
Make a Reference Square

That looks nice, I had thought it would make a good project, but I didnt think of a use for it. Not for what I do, I already have a good square box to check things to and I didnt need the longer length. Still a neat project and thank you for sharing it with us.

Charles

Thanks for posting!

Getting a good sized square for checking vertical way alignments is still on my to-do list, and making one is my most likely scenario as I would like to have more than the typical toolmakers fixed-blade type. At the very least, I'd like it to be cast iron so the surfaces can be scraped flat. I'd like the perpendicularity to also be adjustable (more than just scraping) so that it can be routinely calibrated against a known standard, or set 'off' by a known amount to compensate for post-assembly sag. My initial plan was to make one that you could measure from three points and use trig to calibrate it, but I haven't gotten too deep into it yet.

The other feature I wanted to build into it is an integrated dovetail slide on the vertical section with a mount for standard test indicators, so that you could slide along a vertical surface and indicate how square and flat it was.

Dennis Mayeron out in CA showed me a device he saw and then made to check his Master blade square. It was a bridge that looked like 2 - 1 2 3 blocks sitting on their sides and a parallel spanning across them and he had a 10" indicator rod with a tenths indicator attached to the spanned cross ground bar. He would set the square on the granite table and then set the blade square short side under the bridge until it touched the cross bar and zeroed the indicator on the blade. then he carefully slid the square away from the indicator and reversed the square and slid the bottom under the bridge so he could indicate the opposite side of the blade and they read the same, meaning the square was good. I didn't take a picture. It's late and I'll see if I can find something tomorrow.

I also have done the test Conrad is showing with the ball end of the Starrett gage. Jim Thiele showed me that one years ago. I now use a mag base mounted on a precision ball bearing of a larger diameter. I have photo's of that set up. I'll try to post those tomorrow too. Good night

Here is another way to make a square



Tram the shaft by sweeping an indicator on the surface plate. Accuracy is dependent on the shaft straightness and the sleeve end squareness and flatness in conjunction with the fit to the shaft. I can get the tram within 5 tenths on an 18" circle by adjusting the crews in the base. Fiddly as hell but once it is done you just plop the thing on the surface plate sweep the distance from the shaft at various heights to verify squareness.

dcsipo said:

View attachment 326148

Tram the shaft by sweeping an indicator on the surface plate. Accuracy is dependent on the shaft straightness and the sleeve end squareness and flatness in conjunction with the fit to the shaft. I can get the tram within 5 tenths on an 18" circle by adjusting the crews in the base. Fiddly as hell but once it is done you just plop the thing on the surface plate sweep the distance from the shaft at various heights to verify squareness.

Click to expand...

Nice tool. I'd be tempted to lap the base to establish squareness once and for all. On a base with a recessed center so it has a contact ring near the edge, you could simply weight the high side (magnet maybe) and lap in a standard pattern before checking for square again.

M.B. Naegle said:

The other feature I wanted to build into it is an integrated dovetail slide on the vertical section with a mount for standard test indicators, so that you could slide along a vertical surface and indicate how square and flat it was.

Click to expand...

That seems like a nice idea. Couldn't it be done on a regular square without a dovetail by making a carriage for the indicator to slide up and down. If there were magnets on it that held to the flat side, the contact to the edge might be kept with finger pressure. Or magnets again to the edge. With contact on the edge and one face at the side, a carriage should fit any square within reason.

Here is the slickest square tester. I have had customers buy them when they want me to teach classes. Goya foods in Puerto Rice has a cannery I taught at and they rebuild high speed punch presses and I had them buy one of these and a granite square to double check it. SquareMaster™ | PMC Lone Star

It is expensive, but if your doing production rebuilding, it pays for it self in a few jobs.

scroll to the # 24 to see it in use. July 2015 Scraping Seminar in Puerto Rico

Here are a few ways I show in classes how to check squareness. The mag square works well as it is self checking.

Daryl Smith or our member "Other Brother" showed us several swivels square testers he used when he took the Bourn & Koch scraping class a few years ago. In the class other students were Cash Masters, Matt Cricterly, American Gear machine.(forgot his name), Jim Thiele, I have photo's.

Richard King said:

Here is the slickest square tester. I have had customers buy them when they want me to teach classes. Goya foods in Puerto Rice has a cannery I taught at and they rebuild high speed punch presses and I had them buy one of these and a granite square to double check it. SquareMaster™ | PMC Lone Star

It is expensive, but if your doing production rebuilding, it pays for it self in a few jobs.

scroll to the # 24 to see it in use. July 2015 Scraping Seminar in Puerto Rico

Click to expand...

that is neat...here is one in use

I like things square. Things squared away. Square deals. Square music. I've seen a lot of prints that have a block tolerance with +/- 1 degree called out for squareness. I bet they'd change their tune in a hurry if you ever delivered small parts with the faces out by 1 degree!

Have very much enjoyed this thread and would also add that I have spent a pleasant evening reading Conrad's website on machining tips. Lots of things to think about in there. Thank-you.

Shop Square Addendum

So I should add that while I was doing this project I talked to Don Roberts (this was several years back) asking in his experience if he found the T-shape square, as Moore illustrated, more helpful than the traditional L-shape most commonly found. I can't remember now exactly what he said, but as I was doing one I thought I might as well make two. So here's the companion.



Same basic idea in an adjustable square. With both I made the beam height just under 2" so that common 1-2-3 blocks would clear it when checking and adjusting using an indicator and reversal.



My favored indicator holder has a three point contact so I do need a flat ground slab on top of the blocks, but no matter. And since I was setting up for squareness checking I modified the holder to have a lower contact. In this case a flat edge, but I also have a curved edge that can be swapped in.

Another way to check and set the square is with a comparative reference, in this case a cylindrical square. The engineering part of my brain says that an indicator is better since it quantifies exactly how much it's out of square and you could adjust for half the total reading to get the first close approximation. On the other hand, there are other ways to assess the out-of-square besides watching the light slit. This was a trick I got from an old toolmaker. Using cigarette paper, trap two or more strips between the members you're checking like a straightedge against a way or table. Then try each slip of paper and see how much drag it takes to pull it out. It's not a quantifiable measure, but using pull it can be very sensitive. Machinists are geared to use "feel" a lot in any case.



Sorry about sideways picture, they're correct in the original. I suspect they're rotated because of aspect ratio, and if there's a control on here somewhere for that I haven't found it yet.