Operation with variable radius.

Attached is a screenshot showing your model (left), and a fillet I applied (right). The main difference is the type of fillet being created. Both are variable (10mm to 5mm), but yours is set to Elliptical. I think you want it set to Circular.

Also, look a bit higher in the fillet options too. I just noticed yours is set to Asymmetric. Symmetric should be set if you want the Circular option.

Hello FredSWUG,
I have made the radius as you tell me in the image and the piece does not have the same volume as the piece on the left, I have to get it to have a radius of 10 mm. (top) and 5 mm. (lower). I measure it and it gives me 9.96917334 mm and 4.98458667 mm. How to solve it?
Greetings.

I'm not sure why it does not match the specified radius of 10, and 5mm exactly. The only hint seems to be that the edges formed on the top and bottom of the part by the fillet are splines, and not arcs. This may explain the slight difference in radius from what was specified.

I think you have two options:
1. Model the shape with a loft as was done in the left part. This allows the corners to meet the precise radius you are looking for, and the corners will also have an arc as their profile.

2. Use the variable radius fillet, but perform a little trial and error to determine that the required radius needs to be specified as to obtain 10 and 5mm. Assuming it is a constant, the math should only take a few minutes. Keep in mind the corner will be a spline, and not an arc profile.

It all comes down to what purpose the model serves.
Regardless of the method selected, you should be able to save time by only modeling 1/4 of the part, and then creating the rest via the mirror command.