Scale down SketchUp live size object does not render completely I got a life size model of a signaling post (trains) where I scale it down to 1/87 model (in SketchUp). When I send the model to my 3D printer (with Cura 2.4) some parts of the model are lost in translation even when their dimensions exceed the printer minimal dimension of 0.7&nbsp;mm. 

Is this a known problem of Cura or is something else at hand?
You will indeed have difficulties with scaling a model to the point that individual components become smaller than the tolerances of your printer.

It is more likely a problem with your model, having been created in SketchUp. If you use an online model repair service, it will almost certainly return an indication that the model was flawed. Unfortunately, those repair services are not a good choice for repairing a SketchUp model, as the fail points are usually beyond the capability of the software.

Another option would be to load the model into MeshMixer and use Analysis/Inspector to reveal the flaws, but again, the automatic repair feature would likely destroy the model.

Even a program as simplistic as TinkerCAD will do a better job of creating a 3D printable model.

Consider to begin learning a different, perhaps more challenging program such as OpenSCAD or Solvespace, or even more challenging than those, Fusion 360. All of the above are free, while Fusion 360 has the requirement of non-commercial/hobbyist use to remain free.