A Centerless Filing Button

[rgsparber]

I don't know why, but I have a facination with forming rounded corners on flat stock. The standard way to do this is with a filing button. You drill a hole in the stock, run a bolt through the button and the hole, and add a nut to secure the assembly. Then file down to the button. That hole really bugs me. I did figure out a way to avoid drilling the hole by using hot glue to secure the button. That didn't satisfy me so I kept thinking about the problem. Can't say that I'm done with this journey, but here is my latest "day trip" - a tool that lets me cut a nice 7/8th inch radius in sheet stock. No hole is drilled and no glue is used.

If you are interested, please see

https://rick.sparber.org/CenterlessFilingButton.pdf

Your comments are welcome. All of us are smarter than any one of us.


Thanks,

Rick

[DIYer]

Thanks rgsparber! We've added your Radius Fixture to our Metalworking category,
as well as to your builder page: rgsparber's Homemade Tools. Your receipt:

Radius Fixture by rgsparber

tags: radius, fixture

[baja]

I don't know why, but I have a facination with forming rounded corners on flat stock. The standard way to do this is with a filing button. You drill a hole in the stock, run a bolt through the button and the hole, and add a nut to secure the assembly. Then file down to the button. That hole really bugs me. I did figure out a way to avoid drilling the hole by using hot glue to secure the button. That didn't satisfy me so I kept thinking about the problem. Can't say that I'm done with this journey, but here is my latest "day trip" - a tool that lets me cut a nice 7/8th inch radius in sheet stock. No hole is drilled and no glue is used.

If you are interested, please see

https://rick.sparber.org/CenterlessFilingButton.pdf

Your comments are welcome. All of us are smarter than any one of us.


Thanks,

Rick

Thanks Rick! Just solved a problem for me in rounding corners on metal (or plastic) sign blanks.

[bobs409]

I could see a use for something like that! Great idea. Hmmm, I feel the wheels starting to turn in my head again... Uh oh!

[Tooler2]

Rare earth magnets come to mind.

[rgsparber]

Rare earth magnets come to mind.

I’ve tried using neodymium magnets. They slide. You certainly do not want to use them as filling buttons. They will shatter.

Rick

[Tooler2]

I’ve tried using neodymium magnets. They slide. You certainly do not want to use them as filling buttons. They will shatter.

Rick

What kind of ''filing'' are you doing? I have not tried it out but magnet's field may require a minimum thickness of material to stick properly. Not sure if you use one underneath as well if it would have to be perfectly aligned. Once the curve is well defined one can remove the guide and fair the curve freehand with some skill.
Rob

[rgsparber]

The magnetics I tried take a lot of force to pull straight up. But a slight nudge with the file makes it slide enough to mess up the shape. I suspect that if I had more skill, these bumps would be light enough to not move the magnet.

As shown in the article, I do a lot of shaping on my belt sander.

[Tooler2]

With any method you should be cutting to a line, not actually cutting till you touch the button?

[suther51]

I like this, thanks. Been noodeling on how to do similar rounding with thick stock on a milling machine with out the expense of a rotory table. Or maybe a fudgit home brand table. Thinking along the lines of bike chain, sprockets, mabey angle grinder gear head. Chain n sprockets to keep the hight down on my small mill allowing crank and perhaps index plates to be off the table. All the pieces have not noodeled into place yet.