Acetone Smoothing an ABS Cone - (New to 3D printing)
is it possible to smooth the surface of my print without loosing shape?


That is by definition impossible. Smoothing the surface implies that the geometry is changed. Rather, the question is: how much does acetone smoothing change the shape, and is that change within the tolerances of your application?

Acetone smoothing is a fickle process, and how (much) the geometry is changed depends on a lot of factors, such as the concentration of the acetone vapor, the amount of time the print is exposed to it, the exact composition of the plastic, geometry of the print, etc... It is definitely possible to overdo it and melt your print into a puddle, but it is also possible to smooth it out without affecting the geometry significantly.

I would recommend experimenting with the process and seeing whether you can tune the process (time/concentration) so that you get a smooth enough part without affecting the geometry too much.