Generally it is always a good idea to provide working code so that others have a starting point.

All this is very easy to do in Mathematica. No need to use Excel either, because I see that you build analytic surfaces that can be sampled in Mathematica too.

First I recommend reading

**Notes on 3D printing** by

**Henry Segerman** who did a lot of work on the subject and

**published a paper**.

A rather quick summary for you about specifically your problem. Here is the code:

f[u_, v_] := {u, v, u^2 - v^2};

scale = 40;

radius = 0.75;

gridSteps = 10;

curvesU = Table[scale*f[u, i], {i, -1, 1, 2/gridSteps}];

curvesV = Table[scale*f[j, v], {j, -1, 1, 2/gridSteps}];

tubesU = ParametricPlot3D[curvesU, {u, -1, 1},

PlotStyle -> Tube[radius], PlotRange -> All];

tubesV = ParametricPlot3D[curvesV, {v, -1, 1},

PlotStyle -> Tube[radius], PlotRange -> All];

corners =

Graphics3D[

Table[Sphere[scale f[i, j], radius], {i, -1, 1, 2}, {j, -1, 1, 2}]];

output = Show[tubesU, tubesV, corners]

Export["MathematicaParametricSurface.stl", output]

Here is how the resulting STL file is viewed in an independent STL viewing program - for example

**MeshLab** which is free:

And here is final 3D printed

**result you can find in Shapeways store**:

Now sometimes you will wish to plot surfaces as they are, not as meshes. Here is a simple example.

model = RevolutionPlot3D[{Sin[t] + Sin[5 t]/10,

Cos[t] + Cos[5 t]/10}, {t, 0, Pi},

RegionFunction -> (Sin[5 (#4 + #5)] > 0 &), Mesh -> None,

BoundaryStyle -> Black, PlotStyle -> Thickness[.1]]

Export["model.stl", model];

Import[%]

Now further very useful links: