How Did This Machinist Make This Surface Gauge?

[Janderso]

I love this surface gauge. It's an Ebay find. It's shop made, no markings on it at all.
It feels good to the hand, the quality is very good.

My questions,
How did he cut the rounded sides?
How did he round all the edges?
The top where the two angles meet, it's a clean, smooth transition.

I'd like to try to make one. I believe I have all the tooling.
I just don't know how to perform some of the cuts.
Thank you.
Jeff

 

[Peyton Price 17]

maybe used a radius cutter for the grooves, and a file for the round overs, but that would take some time. the top was probably milled or shaped and rounded with a file.

 

[mmcmdl]

First things first . That is what we in the trade refer to a Toolmakers' Gauge being it has the 4 pins . Other than that , it's easy to make on a manual mill and then finish ground .

 

[wrat]

When I was a much younger man, I worked in a Tooling Department in a aircraft factory.
There were such persons known as "Tool Makers" and this was typical of their output.
They did a LOT of grinding and a LOT of filing, well after their bandsaw work.
To them, lathes and mills were simply for "roughing in" the desired shape. All else was hand work. With files.
Lots of files.

 

[jwmelvin]

That is what we in the trade refer to a Toolmakers' Gauge being it has the 4 pins

How are the pins used?

 

[mmcmdl]

How are the pins used?

Used for checking parallelism on different applications . The pins are the contact points .

 

[woodchucker]

the pins are used on the edge of a project, and can run down the length, to measure lets say an offset of another cut.. either for scribing, or for measuring

 

[woodchucker]

as far as the roundness, like other have said filing. I don't think any of those were cut by a radius cutter.

But you can also get the same result on your own with out filing perfectly.
3 methods.. both should start with filing. Smoothing using:

1. a cratex stone (a rubberized stone, comes in a few grits just keep rubbing and it creates a round if you keep it in the same spot)
2. a wooden block with the shape you want (hard wood like maple)... drill it down the length (short amount with the grain) then cut off half) then use silicon carbide (wet/dry) sandpaper.
3. using a scotchbrite wheel.. (much less perfect)

both tedious compared to filing (also tedious) but less expertise required.

 

[Mini Cooper S]

The seller may have advertised it as "shop made", but that looks absolutely identical to my Starrett surface gauge. If it is shop made, someone sure put a lot of work into duplicating every part perfectly.
Nice find by the way.
Richard

 

[mmcmdl]

The last time I used any of my gauges , I aligned one of our cutoff saws in my current workplace . The linear slides were off compared to the rotating arbors for the 5 blades . I aligned both parallel and also heigth wise within .0005 . I then made up a block and taper pinned all so this was set for life . The supervisor saw this and said that this was way over the top for the operators that changed the blades . He pulled the pins and removed the back bearings off the ass end of the arbor . Didn't matter to me . Anyways , I've sold 4 Starretts on this site in the past , I kept one small one just to look at and remember my past.