How would you trim the thickness of the pad down? What tools? A 4.5" razor cutting guillotine style with the pad on its side seems like what you would need. It would be hard to do without compressing the foam which will end up giving you a wavy cut surface.
I would hold onto the 4" and 3" pads as is. The more I use the Mini 75 the more I am becoming accustomed to fact that it is just not the right tool for many panels. Especially the concave and convex surfaces on the bumpers. Its too much pad movement due to the extra total area the pad covers the and it will be difficult to keep the rotation from stalling. Imagine if the Mini had 21mm of throw, it would stall like crazy on those surfaces. I know, I wanted to make that little $300 machine do it all too. I've gone back to using my 8mm polishers with a 4" backing plate because the pad movement fits those concave/convex surfaces better. I use the B&S 4" pads which are not as thick as the LC ones. I don't own an IBrid yet, so maybe that is truly the ultimate polisher for these types of surfaces and make my point moot. I'll find out one of these days.
That KXK Dynamics Punch set is a good idea. The cost savings is obvious to see after reading their product description. Now, I did not expect it to cost $250 for the set! It would probably take me too long to recoup that cost from the savings you get making your own pads, but some of guys probably would recoup the cost in 6 months. Those smaller pads just don't last very long so you making them for under a $1 a piece is much easier to swallow than buying each one at $4-8 a piece.
