Caliper Radius Gauge

Simply slide this onto the end of your metal caliper, press it against a round object, and take a reading with the depth probe on the caliper. Multiply your reading times 10 to get the radius of the object measured. No complicated formulas needed.

1. Slide it firmly onto the end of a caliper.

2. Press it against a round corner or object.

3. Measure the depth to the rounded surface.

4. Multiply the depth reading by 10 to get the radius. 

Similar gauges with a 90-degree angle require multiplying the reading by 2.414. Who has time for that? I'd need a calculator. This has a carefully-calculated, wider angle so that the depth reading is multiplied by 10 to get the radius. The wider angle has a few other benefits. It can measure corner radii on corners that aren't exactly 90 degrees, but up to more than 120 degrees. It can measure large radii (radiuses?) with fairly short arms. This is small enough to keep with your caliper. It even fits inside the case of many calipers.

Printing: Orient the part with the top down in the slicer. No supports or brims needed if printed in that orientation. If you print the first layer (0.2mm) in one color, pause, switch colors, and then print the rest of the layers, the instruction text (to multiply the reading by 10 to get the radius) will stand out better. 

Caveats: 

1. It must be slid onto the caliper all the way for accurate measuring.

2. It is slightly less precise than a gauge with a 90-degree angle.

3. It is designed for the standard dimensions of a quality, metal caliper.

Example:

1. The second photo shows the depth gauge protruding into the measuring space between the arms. 

2. The last photo shows a depth measurement of 4.9mm, meaning the measured radius is 49mm.