How to cut a radius

[osaleh]

Hi

In the drawings and instructions, many times we are asked to trim parts. I am at the HS-710 and 714. We are asked to make a radius of 1/4 for example for the HS-710 and 714. How can i go about doing that? do i use a compass? any other way you guys use?

Thank you

Omar.

 

[hydroguy2]

I find the easiest way to make a nice internal radius is the drill a hole. Then for outside radius, grab a washer of the correct diameter and sharpie or scribe around it.

 

[rv9aviator]

You can also buy a cheap set of radius gauges and then scribe a line around the edge of the gauge to mark where to cut. They will do inside and outside radii. Look up radius gauge sets on EBAY and you will finds lots of them.

 

[shuttle]

I use a belt sander/bench grinder like the one below with a scotchbrite cutting a polishing wheel for radiusing outside corners.
Sander makes the rough shape and finish with the Scotchbrite. Takes seconds and good enough even just gauged by eye.

As already mentioned, drills do the job on inside corners and definitely agree with the "not a Swiss watch" comment.

As a tip for laying out shapes or cutouts, e.g. for instrument panels, you can use the free software that Front Panel Express offer to design and print an exact template for a shape/cutout, including the centre point for the corner radii. Simply position the template on your metalwork and scribe or centre punch the key reference points through to the material.

Software is here: http://www.frontpanelexpress.com/download/front-panel-designer/index.html

 

[Ironflight]

If it's just a small radius, I do it by eye on the Scotchbrite wheel. Circle template (or whatever is handy) for larger corners. And just like mentioned above, a drill hole for inside corners.

Not going to the moon - just to Denver.....

 

[Doug Lewis]

For the smaller radius I've been tracing a washer that fits the end of the part.

 

[longranger]

I find the easiest way to make a nice internal radius is the drill a hole.

And don't forget to use a drill bit size that is DOUBLE the radius you're looking for. Easy mistake to make...

 

[rzbill]

A practical tip

If you are doing small corner radii with a file or sander or scothbrite wheel, here is an easy method to do it quick.

Put a 45 degree straight chamfer of a shade less than the radius you want. In other words. cut a straight line on the corner that is about the length of the radius.
This will leave 2 "points" on either side of the chamfer to blend in.
A few swipes with whatever tool you are using will blend them in quickly and the finished radius will be pretty close.

I use a circle template and sharpie if I want to get it really close, but I still use the chamfer method as the first cut to the line.

 

[mike newall]

Just done it last night on my new 8.

Use a washer, can't remember if it is a #10 or AN4 washer - get your ruler out !!!!!

You can center it on the last hole, draw around and use a double ended grinder - rough it on the grinder, fine it off on the Scotchbrite wheel.