The mounting plate of a winding form assembly for a flier-type armature winder has a split hub with an axial bore clamped to a bearing at the end of the flier spindle. The mounting plate has spaced segments defined by splits. A clamp screw has a head confined in a bore in the split hub so that, upon loosening the screw, it causes the plate segments to be forced apart, thereby increasing the size of the axial bore so that the plate may easily be removed from the bearing.