Abstract: A rotary scanning device having a rotary transformer in which a transformer ring is glued to a scanning means. The effects of temperature and humidity on the rotary transformer gap spacing are reduced by utilizing a first thin layer of glue between the transformer ring and a support which extends into a hole in the scanning means, and a second layer of glue extending radially between a cylindrical surface of the support and the inner wall of the hole. A radiation transparent support, and radiation-curable glue may be used, so that the two distinct layers may be cured simultaneously by radiation directed into the support through a hole in the scanning means.