How do I duplicate this shape on the oposite side?

[broncomech]

I have attempted to copy paste, project curve, mirror, nothing seems to work. Either I end up with an object that I can no longer alter dimensions on, or the program throws an error message saying it cant do a simple projection.

I need the same feature on both sides with the option to continue the designe in sketch as I may need to alter the dimensions later.

Here is what I am attempting to sketch, the part needs some design tweeks to get it to function properly, would be nice to do it virtually rather than cut another one manually and discover its still not quite right.

[TrippyLighting · Accepted solution]

Here's a screencast of one approach, but this can be done many ways.

[broncomech]

Thank you for the screencast, it took a few attempts but I finally got the part mirrored.