A C172 with 160HP will easy handle 500 m lightly loaded but max weight, hot day, soft surface or slope may be a very different story ! A 140 Cherokee will not be any good on that short a strip !
You want to build an airstrip for anyone and everyone then you need a tar sealed 1500meter runway with clear approaches and departures !
I have a grass farm strip, 800m and use a J230 ! At full weight! the grass is wet and long plus hot it would be dangerous to take off as it won't accelerate fast enough or get enough lift ! I also have trees and a power line to watch for ! With short dry grass, 24deg, 600kg MTOW there is no need for more than 500m,
I don't encourage others to fly in as I do not want neighbours to complain, so as Kasper said " nothing to see here, " .