Please...

[qweqwi]

What happen??...many black lines appear where they should not but are well built ... to apply textures reproduce the error ... just disappear rotating entities ... why? ...

[Roy Hirshkowitz]

Make sure the model is not located very far from the origin.  Make sure the units are correct.  If you can't figure it out, send the drawing and I'll take a look.

[qweqwi]

Thanks Roy ...2d sent us a bad worked that origin in trouble ...

[Alejandro Testa]

Hola, eso pasa mucho con los archivos que uno recibe de otros usuarios, yo lo sufrí hace un par de años y me volví loco hasta entender que pasaba,   para evitar esto en general yo trato de no modelar nada sobre dibujos de otros, claro, esto es mas trabajo para uno...