JP ASTROCRAFT

Welcome to JP Astrocraft, my little astro manufacturing company. I'm John Pratte. I spent over 40 years as an Engineer for a large manufacturer, but recently retired and can now devote more time to my telescope making activities. I've made telescopes for over 50 years, including mirrors up to 20 inches.

In my search for the perfect size personal telescope, I designed and built a 16" F4 which soon became nicknamed the "Sweet Sixteen". Well actually I built four. I have one left for sale from this first production run, the pecan colored scope at the left. The 16" aperture provides "big scope" light gathering, and the F4 precision optic allows a no-ladder 62" eyepiece height. It also means seated viewing including the zenith. The compact design means a 16" scope in a package typical of a 12.5" or 14" scope. It is really significantly smaller than a typical 16" telescope, and a joy to transport. Refer to the Sweet Sixteen page for more information and construction details. You will see why I am proud of the sweet 16. It is available with optics from Lockwood Custom Optics, or from Dick Wessling's Pines Optical Shop.

I have also built a number of custom mirror cells over the years. My cells mount the mirror on it's own support framework and use a pivoting support at the mirror edge to prevent binding. I do not believe slings or glued on supports are the best way to support the edge. The larger cells feature spherical bearings at the support triangles to reduce slop in the pivot. The sweet sixteen cell uses channels that are shaft mounted for the levers, further controlling slop. This frame is spring loaded with stainless Belleville washers to the mirror box frame. This construction results in a strong, easily collimated cell that resists collimation change as the scope is moved while properly supporting the precision optic.

I was fortunate enough to have acquired a reasonably complete machine shop for my telescope making activities. It is great to be able to make the proper part for a scope rather than having to adapt hardware store or commercially available parts. See my shop section for my equipment and custom projects for pictures of special stuff I have done.

If you are interested in a finely crafted "Sweet Sixteen" telescope, special mirror cell, or have a unique need please contact me at:

astrocrafter[at]consolidated[dot]net.