Sirkut, I'm pretty sure I did something wrong with one of your parts, but I can't figure out what it was and can't undo it. After a search in this thread for problems with the Closed Powered Hinge, I seem to be the only one who messed up this way! I've included screenshots to show what happened in flight and a stripped-down .craft file (I think I got all the non-stock parts out). Here's my situation: I have a space station with an experiment module that is finished and needs to come back home. I use docking ports on the experiment to send it up and bring it back (launched with a basic rocket, retrieved with a spaceplane). My retrieval design uses a cargo bay on a spaceplane, with your Closed Powered Hinge to bring out the docking port for attaching the experiment. The hinge is then supposed to close again, safely tucking the experiment into the cargo bay (because I like to use DeadlyReentry for the realism). The problem: After designing my spaceplane (see .craft file below), I tested the hinge movement, set movement limits, and assigned action groups for easy operation. All systems were go, so I launched. When I got to the space station, grabbed the experiment, decoupled, and tried to retract the hinge...nothing moved! I hear the motor sound when I activate my action groups, but the hinge never retracted. Then I took a close look at my cargo bay and noticed the state of the hinge. Here are screenshots (a couple of views, and each view with and without the part menu in case there's any useful info there): https://www.dropbox.com/s/eg6z5tafbxswfs9/screenshot5.png?dl=0 https://www.dropbox.com/s/4iflqooyi7otz0n/screenshot6.png?dl=0 https://www.dropbox.com/s/d499cxijo6hyfjk/screenshot7.png?dl=0 https://www.dropbox.com/s/euq15cl7loq1ml6/screenshot8.png?dl=0 For anyone reading through posts like I did, what happened was the base of the hinge--the part that doesn't move in the VAB and is supposed to be fixed to a surface--decided to become the moving side! It's now closed again with the payload sticking out and doesn't move at all anymore. I thought maybe this was simply a graphical bug, because the "Rotation" value in the part menu does respond to the motion controls, and tried closing my cargo bay doors: https://www.dropbox.com/s/yii4lcsaxopidad/screenshot9.png?dl=0 But the menu for the doors showed that only the same 3 parts were shielded as in the VAB (the hinge, docking port, and an RCS tank), as you can see from the .craft file: https://www.dropbox.com/s/jrtxrchvj6ozhv5/SERP%20Debug.craft?dl=0 What did I do wrong, so I can avoid it next time? Can this be fixed by editing the part in my save file? I'm cool with that, I just need to know which of the many values to change. Thanks for any advice, and thanks for the mod! P.S. I hope Squad recognizes this functionality of moving parts as fundamental and will incorporate your mod into the stock game by v1.0!