I printed this for my 3 year old son in his favorite colors. I am new to printing and this was my most challenging print so far as . I had trouble with the first layer squash making cylinders and pistons flat bottomed. After a couple failed tries I just chased the cylinders with a drill bit, problem solved. I had to print everything that bends twice because my print tolerances were off or I broke during assembly. That's my fault, not unexpected, and two tries for this beauty is a small price to pay.