Double Arm Barn Door Tracker

A camera is mounted on the top board usually with some sort of ball joint to allow the camera to be pointed in any direction.

Double arm barn door tracker.

Construction plans for a star tracker. Sky telescope february 1988 p213 p214. The hinge is aligned with a celestial pole and the boards are then driven apart or together at a constant rate usually by turning a. Double arm barn door tracker.

Sky telescope april 1989 p436 p441 very good. An inexpensive route to astrophotography has long been the scotch mount also known as the barn door drive after its appearance or the haig mount after its inventor. Smits notes that all of dave trott s drives including the single arm version have the drive screw mounted as the expanding base of an isosceles triangle. To use it the tracker is set up in the field so that the hinges are aligned with the earth s axis of rotation.

How to build a double arm barn door tracker jefferson lab home page science education home page construction notes photos page sources. His paper a mathematical analysis of the double arm barn door drive appears on pages 155 160 of the december 1988 monthly notices of the astronomical society of south africa. Calculation of drive arm length. Original concept by dave trott.

A simple single arm barn door tracker can be made by attaching two pieces of wood together with a hinge. For some of my longer exposures i use this device which can track the motion of the stars across the sky while the image is being made. A double arm mount offers much greater accuracy than conventional designs. Make sure everything is square and moves freely clap the 2 hinged boards together and shout action a few times like they do when making movies if it makes a nice clack sound it should work well for a star tracker now measure 228 55mm from the center of the hinge pin down the middle of the board and mark the drive rod holes do this on.