Viewport Rotation

[Mechanical]

Can someone smart with Autocad tell me why this happens?

Okay, in modelspace I have a drawing that is aligned perfectly, but when I create a new viewport in a layout the drawing that was created in modelspace seems slightly rotated in the layout view?

Can someone please offer any suggestions.

[Dadgad]

You say that in Modelspace it is aligned perfectly, which begs the question,
to what?

If the UCS in your modelspace is something other than WCS, you would experience a different perspective (either slightly or wildly) in your
newly created viewport.

Another possible scenario might be that your Modelspace view is set to PERSPECTIVE view as opposed to PARALLEL view.
Try entering PERSPECTIVE at the commandline and making sure that it is set to ZERO.

Are you at liberty to post the drawing, or a very stripped down version of it, which is all it would take to debug the problem?

[BIGAL]

A bit more if you have set your modelspace to a diiferent UCS then just UCS S name then in viewport UCS R Name plan

[khoshravan]

Another possible scenario might be that your Modelspace view is set to PERSPECTIVE view as opposed to PARALLEL view.
Try entering PERSPECTIVE at the commandline and making sure that it is set to ZERO.

I thought perspective command is only deal with 3D objects.
How is it used in 2D drawings.
I checked ACAD help but didn't get the point which I quote here.

Perspective projections require a distance between a theoretical camera and a target point. Small distances produce severe perspective effects; large distances produce milder effects.
A perspective view remains in effect until the perspective effect is turned off or until a new view is defined in its place.