Head speed
I glued my airplane tach to a piece of spruce about a foot long. I stick it in the ground and hover over it. When I was first starting I'd just sit the heli over it and read it when the heli started to get light on the skids.
Brian, where did you get a GV-1 for 125. At that price I'll take one! After spending nearly 2K for new radio, engine, X-cell Fury, servos etc. I'm about broke and decided to forego the GV-1 at lhs that was $180.
Later,,,basmmntdweller