[Tristan Lall]

One thing I value—and I know Ed values as well—is accuracy.

Essentially all of the parts on FirstCadLibrary are carefully modelled with accurate dimensions and proportions. This is especially difficult with things like motors (that have a large number of complicated features).

While designs using the simplest motors and the provided gearboxes don't really need to pay much attention to the minor aspects of the shape of a motor, occasionally FIRST gives us something like the Bosch/Scintilla drill motor (2003 and 2004) that has features that are non-obviously important to some designs (diameter of round holes on face, thickness of case, position, diameter and depth of side holes, etc.). In a situation like that, I want to be able to depend on my CAD model to give me good information, so that I can make parts without worrying too much about how it will fit.

Even though I have the ability to measure it and model it for myself, it saves me time to have a reliable source for models. Since CAD can sometimes be a limiting factor in producing accurate parts (e.g. when you have a fast machining method provided by a good supplier), every advantage in the drafting process is worthwhile.

So accuracy is a priority for me: if it's not a good model, I don't even want to know it exists!