It's making use of the "1 in 60" rule for small angles: Tan of 1 degree is approximately 1/60
I thought that originally you were looking for 180 degrees travel on one axis and 90 degrees travel on the other. You don't need anything like that to scan a 200mm object at a range of 1000mm.The greater the travel you need the harder it will be to achieve the resolution, so try to work out what you actually need.
Please enter a valid email to subscribe
We need to confirm your email address.
To complete the subscription, please click the link in the
email we just sent you.
Thank you for subscribing!
via Egeo 16