Ready References
A Guide to Backyard Astronomy
Understanding Celestial Coordinates
Latitude is Everything
Using the Hands-On Astrophysics Manual
Stepper Servo Motors
Molding and Casting
The Use of Fused Silica
Ready References A Guide to Backyard Astronomy Understanding Celestial Coordinates Latitude is Everything Using the Hands-On Astrophysics Manual 
Stepper Servo Motors 
Molding and Casting The Use of Fused Silica