I am making a glider with manually retracting gear.  There is some kind of weirdness going on with the contact points. 
Tried everything.  If I make all the contact points wheels, then the gear animation works, but the simulation does not know when the main centre wheel contacts the ground, so the aircraft sinks into the ground past the wings and crashes.
If I make the contact points - other than the main centre wheel – scrape points, then the gear contacts and the aircraft sits correctly, but the gear animation does not work.
If I make the contact points skids – which is the correct option for a glider – then the sim again does not know where the gear is and also the animation does not work.
Any ideas anyone????

Harold
www.dickert.ca/swift