ORIGINAL: Daniel Z
I just use a dremmel on plastic spinners
I really wouldn't want to run a plastic spinner on an engine that's turning an 18x6W prop, like he said an OS 1.60.
By that size you really want to be invested in an aluminum spinner - espeically on large 4 strokes even more so.
I run 18x6W and 18x8W APC's and buy the tru-turns made to fit those specific props from Tower, but like you said they are not cheap.