Okay, so like the title of this thread says, I think I might have figured out a way to fix the articulation on G1 PowerMaster Optimus Prime, and its very simple really. This is mostly for fixing arm articulation on the cab robot mode. For those of you that own the Hasbro version, you will note that on the sides of the arms, there are 2 screws for each arm that hold it to the smokestack. Unless there's a pin, then there is a way to give our PowerMaster friend here new found articulation. All you will have to do is the following, which I too will be attempting as soon as I can find: Step 1: Unscrew both screws on each arm and remove the entire arm unit from the truck doors. Upon doing so, the smokestacks will also disconnect. Step 2: You will see 2 plastic tubes for each screw on the smokestack. Take the arm and smokestack and place them on Prime as if you're reattaching them, but leave the second tube on the bottom disconnected. Step 3: Replace the top screws only and then test out joint tightness. If this should resolve the articulation problem and have a still tight fit then re-remove the arm once more. Step 4: Cut off the second tube on each smokestack, and then reattach Prime's arms. If this project works, you will gain 1 new point of articulation in PowerMaster Optimus Prime's cab robot mode. Overall, I love the PowerMaster Prime toy, but you know, Hasbro, in my own opinion only half-assed it when they gave him such limited articulation. But I personally think that this could turn out to be a quick fix and to possibly be something to send in to Hasbro as a way to improve the toy. It just so happened I was bored out of my head, and I was playing around with PM Prime and I noticed this. As soon as I get a small enough screwdriver, I'm attempting this surgery for him. I hope this thread proves useful to anyone reading it!