Surface Plate Square

[rossbotics]

I was using the surface plate the other day and accidentally hit my granite square almost knocking it over onto the plate, boy was that scary! If I hadn’t caught the granite square it could have landed on the plate and possibly broken it rendering the square totally useless, that’s when I decided to make a smaller square with a large base.

I had a piece of O-1 tool steel that measured 3/4" X 2-1/4” x 16” so I sit down and drew up something that I thought would be sufficient enough for my needs utilizing the materials I had on hand, the base measures 3/4" x 2-1/4” X 4”, and the blade measures 3/4" X 2-1/4” X 5-1/4”, both pieces were precision ground parallel and square on all six sides before any machining was performed.

After the machining was performed the two pieces were then hardened, tempered and precision ground all over, they were then assembled with two 1/4" dowel pins and two 1/4" socket head cap screws, the bottom of the base was then reground to insure flatness, the blade was then very carefully reground square to the base within .0001” using my granite square as a master.

I have included various photos of the machining and grinding processes it took to make the square along with a video of its usage, this square will be used in the place of the granite square or the cylinder square, periodically this new square will be checked for stability using the granite square as a master.

As always thanks for looking and happy machining
Doug

[Paul Jones]

Doug,

I like your detailed photos and work descriptions. Your contributions are always very informative.

Thank you,

Paul

[old_toolmaker]

rossbotics,

Nice work as always, Doug!!!
Thanks for sharing with us.

[rossbotics]

Doug,

I like your detailed photos and work descriptions. Your contributions are always very informative.

Thank you,

Paul

Thank You Paul

[old_toolmaker]

rossbotics,

Doug, I forgot to ask; where did you get the granite square?

[rossbotics]

rossbotics,

Doug, I forgot to ask; where did you get the granite square?

Hey Dick
I got the square from a place called Penn Tool Co. a few years ago, here's a link to the square Precise Precision Granite Square 10" x 6" x 1" Grade 00 - 303-916 - Penn Tool Co., Inc

I'm sure there are other tool companies that have the same tool or maybe even E-Bay

Doug

[old_toolmaker]

Thank you , Doug! I will check them out.

[PJs]

That Granite is pretty good I'd say @ 89.999427042204893° or 3.597937351927e+17 arc seconds. Surprisingly inexpensive for being that ON! And your new one is as good, Wow! Always, Amazing builds and write ups Doug. Thank you for posting this fine build.

PJ

[rossbotics]

rossbotics,

Nice work as always, Doug!!!
Thanks for sharing with us.

Thank You Dick

Doug

[rossbotics]

That Granite is pretty good I'd say @ 89.999427042204893° or 3.597937351927e+17 arc seconds. Surprisingly inexpensive for being that ON! And your new one is as good, Wow! Always, Amazing builds and write ups Doug. Thank you for posting this fine build.

PJ

Thank You for your comments as always PJs
When I bought the granite square I didn't think it was to astronomically priced either, and it's a heck of a lot lighter than a steel cylinder square, I have a 3" X 6" steel cylinder square and it weighs about 12 pounds compared to the granite square weighing in at around 6 pounds, and the tolerance is + or - .0001" on either one, just have to be a little careful with the one made by Fred Flintstone is all.

Doug