Hello everybody, I feel like a real idiot asking, but I am stuck trying to assemble the links on my SCX10 ii kit. Am I missing something or doing something wrong here? I cannot for the life of me get the plastic end pieces to screw on flush to the link arms. Here is a pic: I dont know if I need a vise, or what why the hell I cant get these to twist on any more. Thanks in advance for the help!!