Hi MrShaunL,
It does sound like the motors are drawing too much power then. The second battery pack could help solve this.
If you were still looking to create tracked vehicles, we do sell tracks and the relevant wheels for the gearboxes on our partner site https://mindsetsonline.co.uk/shop/caterpillar-track/
He definitely does look like a prototype Wall-E, fantastic!
Kind regards,
Dan
