Here is my second heliostat prototype. It’s one major improvement over the first is the way the stepper motors are set up to move the mirror. This prototype uses a simple threaded rod / lever arm arrangement instead of the worm gear setup I had on the first one. The worm gears on the first one worked well enough, but they are hard to make from scratch without a CNC machine, so I decided to omit them in order to make it easier for people who don’t have one.
Now, there is something that I need to say about this heliostat. It never worked (ARRGH), and I cannot for the life of me figure out why. Everything checked out, but, for some reason, no matter what I did the reflection from the mirror would not stay on target. Within a couple of hours, the reflection would drift away and miss the target completely.
I must have checked everything 100 times at least, but never had any luck. I finally decided to just scrap it and hope that whatever the problem was would disappear with a fresh design, which it did by the way.
I am going to assume that I just messed something up instead of blaming it on the gimbal design. It was most likely an issue with getting it aligned correctly.
In any case, it has some other problems as well. For one, you have to change the dimensions every time you want to use a different sized mirror. I wanted to build several heliostats, and all of my mirrors are different sizes, so I would have to figure out the dimensions for each one separately.