This script has been in my toolbox for a long time, so I’ve taken it out, polished it up, and partnered it with a friend. There are probably other scripts out there that will do this for you but I hope you will find mine intuitive and easy to use.

Ladies and gentlemen I give to you Align Tools

Download here

1. Align to three points

Pick your source objects, activate the tool and then click the three points. Max refuses to show the snap icon after the first click but it will snap correctly.

2. Align to an edge

Pick your target object, select and edge in the sub-object and the click the tool. Now either click your source object or right click to have a dummy created along that edge.

Installation:

Download the mzp package and drop it into your max viewport.

customize | customize user interface

choose the JNScripts category and the two tools should be listed. Drag them onto a toolbar. You may need to re-start Max in order to get the icons to show correctly.

If I can think of any more then I will expand the toolbox. Requests welcomed.