A mounting device comprises a collar part including a plurality of ramp portions on an interior side of the collar part, and a rotatable hub part comprising a plurality of protruding portions. The collar part is positioned around the rotatable hub part. When the rotatable hub part is rotated, respective ones of the plurality of protruding portions are configured to press against respective ones of the plurality of ramp portions and exert a force on the collar part which increases a dimension of the collar part.

A platform assembly with platform extending in a horizontal plane with a bottom surface, a vertical support member coupled to the platform and a C-clamp. The C-clamp comprises a horizontally oriented side coupled to the vertical support member; a first and second vertically oriented side extending downward; the second vertically oriented side comprising a threaded hole. A screw comprises a handle at a first end of the screw, and a shoe at a second end of the screw. A second end of the screw passes through the threaded hole and extends horizontally toward the first vertically oriented side of the C-clamp. Movement of the handle causes the second end of the screw to further extend horizontally toward the first vertically oriented side of the C-clamp such that the shoe and the first vertically oriented side of the C-clamp engage a support structure.