A couple of people have mentioned that they are having difficulty reading the verniers on their calipers. The chaps on the Model Engineering Clearing House suggested using digtal calipers which was then followed by a discussion on the accuracy of using such a techniques.
This got me thinking about an article I’d seen sometime back about using a USB camera for a centering camera. It turns out that Mike’s also had the same idea and he’s already produces some software that allows you to measure things, he cleverly set it up so you can calibrate the camera using a simple ruler.
Given Mike’s images and results perhaps a microscope is overkill, a camera should have sufficient resolution although looking at some microscope reviews the 20x mode looks to be about right. The built in LEDs are also a useful feature of such microscopes.
If you wish to use Mike’s CentreCam software, I would advise checking with Mike about any compatibility issues before purchasing. However, some of the some of the top end USB microscopes available already come with measuring software.