Torso

Mid-body building

Hips

Now that I got the legs done, I attached them to the hip block. With these the guy'd stay standing firm, unless the rest of his body wasn't too heavily off-balance.

At this point the lower body got tightened into the baseplate, as in every other Transformer model so far. The pose was a bit more open than I expected, from the straight as arrow like in the toys it turned more into a ski-jumper's V style.

More recognizeable bits

The truck's radiator grille - sixpack of Optimus Prime was one of the key pieces that screamed who this character was, as soon as I had attached the piece to the model-in-progress. Just like the cockpit's windows just made the effect stronger. Building was a joyride at this point.