This work vehicle from HuiNa does not require you do do any assembly before driving it. The scale of it is 1:14.
From Amazon
HuiNa CY1592 1/14TH RC Excavator 2.4G 22CH w/DIE CAST Bucket Vehicle, Yellow
Model Bau
Huina 1/14Th Rc EXCavator 2.4G 22Ch W/Die Cast Bucket CY1592
OnBuy
Huina 1/14Th Rc Excavator 2.4G 22Ch W/Die Cast Bucket