Weather Resistance and Final Touches
After 7 months of laboring over plans, lumber lists, and making financial decisions, the new observatory is now finished and ready for the mount and schmidt camera. This installment chronicles the flashing trim, and installation of the mounting, which was completely designed and manufactured by the author. It is important to understand the nature of "sealing" a roll off roof structure. I have built three now, and a fourth is in process. The idea is to allow ventilation during the heat of the day to allow the insides and the telescope to not get too warm. If this occurs, it will take hours to equalize with the surrounding air temps at night, and the seeing will be very poor. It is my experience that the best solution to this is to allow gaps in the roof seal and in in between the trusses on the sides so that air may flow through and keep the temperature in check. By doing this, only an hour of cool down is needed to be ready for sub arcsecond resolution in imaging.
Click on the thumbnails for the 800x600 sized image.
September 2002 images
Front side, weather stripping. The trailing edge of the roll off roof is sealed with six inch flashing bent outward several inches at about a 30 degree angle to allow water to run off and not blow into the gap. This must just clear the top of the wall when being rolled back.
Rear side, drip edge. The rear is the same, an angled piece of flashing to keep water from entering and form a clean edge for snow to slide off.
Front side, double door sealing details. The seal over the double doors is eight inches of flashing as well. Note the peak is bent to match the contour of the door, and the very tips are bent up slightly to keep the doors from catching the corners when being closed.
Main entry way, weather resistance. Water runs off the door, and is deflected by a gently sloping metal sill.
Double doors, inside view of seal. Although you can see light over the top, it is completely tight to the pounding rain.
Mounting installed! After what seemed like forever, today we installed the mount. It has a 2.5 inch solid steel RA shaft, 3 inch steel DEC shafts, is made of 1/2 inch thick 6061 T6 alumininum and has a brand new 10 inch Byers Starmaster drive. It can carry a 300 pound telescope effortlessly. It should carry the 20 pound Schmidt camera just fine.
The Author with the new mount. Why is it so high off the floor? Because the mount is designed to carry instruments such as SCT and Refractors with the business end on the bottom. I'm through crawling around on the floor to line up a photo!