3D printing of curved object

How smooth are objects with many segments when 3D printed. I was wanting to model an object for my brother. But he is afraid that he will have to sand the final object down when he 3D prints it. If I model it will hundreds of segments will it print smooth?

Why not print a few small rings with various segments and see what is acceptable?

He is going to have to pay to have the things he needs printed.

Oh, sorry the “when he prints it” part tripped me up.

It would be worth checking with the service that is doing the printing to see what they need from the .stl files and what their printing resolution is. That’ll guide you in how many segments you need to use when modeling curves.

jimhami42 created a plugin that might be helpful. See:

Thanks. I will tell him

It also depends on the shape and the material.
Some shapes may lend themselves to SUbD or other smoothing options.
Some materials will be more coarse than others and some will always need finishing, some of the cost is in the finishing.

what do you mean some of the cost is in the finishing? Do some services offer smoothing of the surfaces.

The material and type of printing can require finishing, printing in metal needs professional finishing.

Ok, thanks. He is going to be printing in something like the resins he uses to make things by hand now.

Yes, for example the i.Materialize folks offer to print some materials in a raw form and in a processed form (as I recall).