Robin: Personally, I like to create one to one templates for parts and assemblies I am recreating. However, I came across this handy printable tool and thought I'd share it for those who might find it useful. Often when something that scales to say 8.7 mm, it can be easier to measure say two foot rather than 'guesstimate' 8.7 from a steel rule for those who don't have a digital vernier.