sound of machine gun. (Bratatat! is a Roy Lichtenstein painting)
CHUGGA chugga chugga CHUGGA chugga chugga CHOO CHOOOOOOO
steam engine or train. from this book: 
Click here for more train sounds
sound of a coin put into a vending machine (from the graphic novel "Jimmy Corrigan: The Smartest Kid on Earth", ref)
sharp rapping sound repeated, often a machine gun. also : rat-a-tat; bratat
RRUUMBLE SCRUNCH SCRUUMBLE SCRUUUNCHH
Sounds made by a bulldozer. From: 
construction equipment machine heavy engine
sound of a washing machine , "[Aredelia] found Starling in the warm laundry room, dozing against the slow rump-rump of a washing machine."
(Thomas Harris, Silence of the Lambs, 1988)
sound of a machine gun (title of a Roy Lichtenstein painting)
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