Ultra Magnus has been in-progress for a while. The main reason is that it's been really difficult to figure out his transformation. I don't want any kibble, (parts that stick out from the transformed or untransformed mode due to transformation). Right now his arms are sticking out from the rest of the truck, which probably loses him a lot of aerodynamic-ness. It's also been an uphill battle to figure out how to get his shoulders to rotate above his arms without having to do it magically. I'm even considering completely scrapping the shoulders and trying again, but there are still a few things I'd like to try before it comes to that.
A rough concept of the body. There needs to be several joints to get the current system to work, however if I remodel the shoulders, I can fit them loosely around the arms.
I'll keep you posted in further updates.