Heliostat

[edit] Introduction

Aim of project. I want to make a simple heliostat on polar or equatorial mount. I wish to make it as simple as possible with no computer control needed.

First some basic theory! If you have pointers of equal length, one pointing at the sun and one pointing at the target, the plane of a mirror that reflects sunlight to the target will be at right angles to a line bisecting the angle between the pointers. If we tie 2 identical rubber bands together, and attach one to each pointer, the point where the bands are tied to each other defines a centre point that this bisecting line will pass through! And if we tie string to each corner of the mirror, have them meet in the middle (like a string pyramid), we can keep the mirror aimed between the sun and the target in 3 dimensions! Now, all we need is to track the sun automatically and we have a heliostat! To track the sun automatically, you need an equatorial mount turning at 15 degrees per hour. So now we have this generalized diagram. The heliostat! where the sun pointer moves but the target pointer is fixed and the mirror moves in reaction to the suns and sun pointer's movement. Instead of rubber bands, you could have a springed device that releases 2 strings from one roller in the middle Here is my first model to test if it works in principle.["http://www.youtube.com/v/WRTX1S7PD-U"]