AAVSO Observer Code CMJA / Minor Planet Centre Observatory Code H61 / Global Telescope Network Partner GTN-33 / Center for Backyard Astrophysics
Dome Sag Brace
After I read reports from other Home Dome users about the dome sag which creates a narrowing of the dome slit opening, I decided to measure the width of the slit on my dome at about 1-foot intervals from top to bottom. Sure enough the slit opening is more narrow at the top by about 0.75". To true up the slit opening, I fabricated an adjustable brace from a collection of 2" aluminium angle, various bolts, a turnbuckle and some chain. I opted for this adjustable affair over a fixed length brace just in case the dome sag changed over time. The turnbuckle draws together the ends of the two angles, the opposite ends of which hang from the top flange bolts that connect the east and west flanges of the dome sections. The inside face of the aluminium angles push out at the top ends of the dome flanges, thereby widening the slit opening to a consistent width from top to bottom.