mechanical fitting

[Vito18]

Hello everyone, I am new in modeling 3d and I am not minimally experienced in the use of modeling software (currently use rhino8), I would have a problem, I can not correctly make a connection between two solids(the one highlighted by radius 2):

I don’t know what function you need to use, the only one that seemed to me approached is “fillet surfaces” that gives me this result:

but in this way it does not cover the entire surface, if instead the "extend" box in the "fillet surfaces" function I have this:

That doesn't match.

 

[meccanicamg]

It is a fitting that must take three curves.... it also extends on the sides.

 

[Vito18]

It is a fitting that must take three curves.... it also extends on the sides.

and what is the function you have to use so that the connection matches the curves?

 

[meccanicamg]

and what is the function you have to use so that the connection matches the curves?

the connection made in your last image is correct.
certainly could have as a variant the constant radius until the end. probably if you do not have other options on the treatment of the rays you have to do the bigger piece, you will radiate complete constant and then cut.