Roc Tan has 8, 10, 12, & 18″ diameter hoop and bases available. As essential parts for accurate wind direction readings, the steel base fits over a 1″ diameter pipe, which should be at least 12″ long on top of pole.
The 24 & 36″ steel swivel units are equipped with nylon bushings. These nylon bushings are long lasting and require no maintenance. The unit attaches to a ½” fNPT (Female National Pipe Tapered thread) connection at the top of your pole. Our swivel unit has a ½” mNPT (Male National Pipe Tapered thread) on its bottom.
The steel hoops have an extension which preloads or holds the sock partially open. This preload helps prevent the sock from wrapping around the pole and promotes more swivel sensitivity in lazy winds.
Hoops & bases are sold only with their accompanying sock orders. Replacement socks are also available upon request.
From the very start, Roc Tan’s hoops & swivel units were purposefully designed without bearings.
Rotation of the windsock frame with ease is paramount. The windsock wraps around the pole if the frame does not rotate into the slightest of breezes.
Bearing lubrication tends to dry out and in cold weather the bearings stiffen. Bushings don’t rely on multiple parts to eliminate friction like bearings do. Roc Tan’s objective was to use a material that had high lubricity with sufficient yield strength to withstand any deformation during operation. The loads and rotation speeds in windsock frames are very low. Nylon bushings and washers can withstand this weight with very low friction comparable to a ball bearings. Lightly loaded nylon bushings are self-lubricating, run without maintenance or external lubrication and are extremely robust with high abrasion resistance.