Well, for starters, here's what I've been working on:
The Agusta Westland A-109 fuselage arrived as well as the 4 blade flybarless rotor and fiber blades.
Windows are now in, and since it didn't come with any side windows I got blue tinted acrylic instead of clear.
Landing gear is in, and I'm waiting on more wheels. I have the aluminum hub on the nose gear, but had to order more for the rear so I could replace those cheezy plastic hubs and foam wheels with scale duals.
The nose wheel is now operational and I'm still working out the hardware for the rears. The gear retracts.
On a 7 channel radio intended for planes or helis, one channel is intended for retracts or flaps. In a heli, if you want to control the gyro gain from the radio, there's a channel for that. Since this is a scale project, and won't be intended for 3-D flight due to it's weight, I'll set the gyro with it's manual adjustments and have another free channel to either run the rear gear with that switch, or use it for lights.
Now, the difference between a standard heli and 3-D is in the rotor AND radio. The small helis and the cheaper ones use a fixed pitch blade that's pretty much just a fan. A 3-D heli has a fully operational rotor just like a full sized one. That means each blade adjusts to positive OR negative collective as well as cyclic pitch.
That allows you to flip the heli inverted and fly it or skim the ground with it while it's upside down, since the rotor blades are now moving air in the opposite direction. That's also what allows it to auto rotate and land in an engine out condition.
The radio allows for 3 different flight modes of 'throttle up' as well as dual rate controls. These are all set according to how extreme you want to get, as well as settings for gentle or scale characteristics.