Mechanical CAD: 3D Printable Device

I have an idea for a compact, fully functional tool / device that I want to manufacture on an FDM printer. I already know the features it must perform; what I need from you is the engineering detail that turns those ideas into a clean, ready-to-print model... (Budget: ₹600 - ₹1500 INR, Jobs: 3D CAD, 3D Modelling, 3D Print Design, 3D Printing, CAD/CAM, Fusion 360, Mechanical Engineering, Solidworks)