Hi Keith,

This is how I have done it in my ZN Synergy, should work fine in the Impact as well. The black paper tube is from Gator RC. I glued it in with a small bead of Polyurethane glue, which foams up when curing. Weighs very little.

[link=http://www.gatorrc.com/gator/fl%20servo%20tube.htm]http://www.gatorrc.com/gator/fl%20servo%20tube.htm[/link]