I make this system from mostly old 2 x 4 boards from pallets and other wood scraps. The truck is capable of hauling the trailer behind it, a camper on it, or a dump truck body on it. The accessories fasten with a wooden dowel into a hole. The wheels all turn and the trailer will turn around corners. It is fun to watch children try to put the different bodies on the truck. You will laugh out loud at their antics.
The learning part of this is the colored blocks. The blocks for the dump truck will not fit into the trailer, so your little tyke can learn about different sizes. I sand all the edges as smoothly as I can so we have no splinters if possible, and paint everything with paint that will not harm people once it has dried.
When I was a boy, (when Moby Dick was still a guppy) most of my toys were hand made. I wish I had kept them. They would be almost priceless today. These can be the same way if stored away after each child has outgrown them.
Dump Truck Body
Tractor Trailer on Truck
Views of Trailer Full of Blocks
Camper on Truck Body