Crossing Gate N (1/160) mechanism. These are desinged to be mounted to a round brass tube for a mast. The tube size can be a maximim of 2.4mm (3/32 inch) outer diameter. A pin maximim of 0.6mm is also needed to attach the two parts and make the crossing gate operable. The actual gate can be fabricated to any size you need using strip styrene. Use in conjuction with these crossing signal
https://www.shapeways.com/product/GKPZPCUKZ/crossing-signals-n-1-160-single-and-double-sided