Hi Mike, (and welcome) First of all, don't talk about images as they are 2D raster images and we are talking about 3D vector based modelshere, right? Now as for imported models; they are most probably scaled right (I mean 1:1) as you shlould aslo make your models. So first of all, make sure that you are modeling in the correct scale (1:1). To make sure, use the tape measure tool to see how big YOUR model is (I know it's all virtual but still we need a refernce to "real world" in virtual reality as well). If something is out of scale you have two choices: use the tape measure tool to scale a group/component or a whole model use the scale tool to scale any geometry (primitive/group/component). If the conveyor belt is the "culprit" (being out of scale) of course you need to scale that, not your model.

Hi folks. With scaling, everything in the component will be scaled. If the change in frame size bother you, you can use the Move Tool. For example, if you want to increase the heigth and the width of a window but keep the framing the same size as the original, go in component edit mode, select the top frame and move it up. After that, select the right frame and move it right. The other lines attached to the selection, will stretch automatically. Of course, you may select the bottom frame and move it down or the left frame and move it left. If the component is made of subcomponents, you may have to dig deeper into these to edit them one by one. Just ideas.