In sketchup there are a number of ways in which you can import an image. These are outlined in the short video below that’s made by concept3d.
With this in mind I thought, I would have a go at copying an object from an image. I choose a toothed gear thats attached to a stepper motor out of a printer.
I took a photo from directly above the gear wheel from close up and then imported it into sketchup.
From there it was a simple task of tracing over a single tooth on the gear wheel, then copying this trace around for each tooth, rotating it as I went. The perspective is not quite perfect but by repeatedly copying the outline of just one tooth, all other teeth should be identical. After less than five minutes of work I had an outline of the gear wheel.
Then it was a simple case of accurately measuring the original gear wheel and using the scaling tool to correctly size the model. Lastly, I used the pull tool to pull the object up to the right height.
From there it would be a simple case of exporting the model to an STL file and hitting print. This particular object is most likely too small to be printed but the idea is there. The object is also not a mathematically perfect toothed gear but I think it would be close enough to use.
There is no reason why you couldn’t use this simple and quite obvious method to model a range of objects you already have and make copies. If this is breaking IP laws I have no idea.. If you would like to become more familiar with skethup have a look at the introductory videos.
I did originally try to use the ‘Match Photo’ function, shown last in the video, to create a scale 3d model of some other objects. However the match photo system is really designed for producing models of simple buildings, not small objects with lots of geometry. As such it proved too difficult to get a model to match up from multiple angles and photos. Using a camera on a tripod and a rotating platform to take multiple photos could improve things and so I will give this a try another day. For more information on the Match Photo system take a look at the video found here.