In assembling the glider the manufacturer had a welded nut on the base of the glider it was not welded correctly and it would not take the screw without striping it and would not screw in all the way leaving a gap of 1/4".  My husband had to re-tap and get another metric screw to fit. Some what of a hassel but got it fixed and now it's perfect.  This is not your fault just an error on the manufacturer..Now it's just what I wanted and I love it. Thank you