Can somebody recommend where to find a set of 3D files of gears and

Can somebody recommend where to find a set of 3D files of gears and a motor to buy to power them? Basically I’m creating a miniature street-cleaning truck, like in NYC. So instead of two gutter brushes rotating at 30-degree angle to the ground, I need to use 6 gutter brushes lined in two rows, so the debris is swallowed by the first two brushes and the ones atop continue the debris transfer to the garbage storage dumb at the end of the platform angled 30 degrees to the floor. The top of the platform is the edge where the top of the garbage container is.
Any recommendations?
Thanks so much!

Thingiverse hosts many parametric gear generators (including herringbones).

I’m new to 3D printing, what do you mean by parametric?

Parametric designs usually center around OpenSCAD (or the OpenSCAD-derived Makerbot customizer). It’s basically a single file that you feed with your desired parameters - like pitch, tooth count, bore, thickness and so on and OpenSCAD will derive a custom part made to your specifications.

I use MakerBot Replicator 2X, and one thing I don’t know is to measure how big the models will be when printed. I mean visually I can see the models on the build plate in Makerware but it doesn’t show exact dimensions of the model…

Netfabb Studio Basic (along with Meshlab) is practically the swiss army knife of .stl manipulation - you can repair, scale, rotate and measure files in a breeze.

@Thomas_Sanladerer Just a precision on that statement. Parametric designs on Thingiverse usually center around OpenSCAD. But parametrics are not exclusive to OpenSCAD. There are many parametric CAD software with a more conventional GUI which allows you to create a parametric model interactively and graphically with a mouse, and toolbars. There are a few on Thingiverse created with FreeCAD which like OpenSCAD is open source.