I often hear comments such as "I want to control the alignment of the part model during new sketch creation" or "How do I control how the part model aligns to the origin axis of the model when I use the "Look At" command". This article will probably not explain why every alignment occurs but I wanted to point out one control in Inventor 2015.
The Application Option setting is the same for both situations but when a new sketch is being created, another application option setting is required. It is set active during Inventor installation but it needs to be verified before I go on. In the Application Options dialog box under the Sketch tab, make sure the option shown below is active. This setting will automatically align the plane, on which you are creating a new sketch, with your view basically creating a 2D sketching area.
The Application Option switch I want to discuss is located on the Display tab and is at the very bottom. You will find it under the "Look At Behavior" heading.
When you first install Inventor 2015, the "Perform Minimum Rotation" is set by default. When you create a new sketch on any plane, in this case a plane on the part model, the program will calculate the closest 2D view and present it to you for sketching. Depending on the initial orientation of the part, since it rotates the minimum amount, it may leave your sketch oriented with the horizontal axis 90 degrees to what you expected. You must be aware of this since horizontial and vertical sketch constraints will be affected.
You could always rotate the sketch 90 degrees but that can be accomplished automatically is you choose the "Align with Local Coordinate System" option.
When you created a new sketch with this setting, the part model may rotate more but it will always end up with your 2D sketch view aligned with an axis that is always horizontial to your 2D view. It may be a combination of all the axis but it always presents one of the axis on the horizontal and your sketch constraints will match your sketch.
The choice is yours, but if you keep undoing a lot of horizontal or vertical sketch constraints because you selected the wrong one, it may be a good time to change your options. A little hint - if you show your sketch axes, the darker one is always the horizontal axis. So many choices but that is what makes Inventor so interesting for everyone.