This 87th HO scale file will print four lift axle assemblies, which fit all of the frames I offer, and with minor modification, should work with almost any HO scale frame. The axle 'hole' is designed so the wheel can ride on the ground, or be placed in the upper position. This file has passed the normal software checks for the detail materials, but should there be an issue, contact me via the shapeways designer link, or directly via email to modelmechanic@gmail.com.