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Controller
This is a simple flat plate actuated mirror design heliostat that can be used to reflect light or orient a PV panel towards the sun.
I spend some time looking at the available options to achieve the necessary freedom of movement to track and refelct sunlight. Because if you are reflecting 90 degrees movement cover 180 degrees incident sulight (and other angles won't matter) i realized the little moveable wheels under shopping carts could do the trick. Here is one taken apart.
You can find them for 9 Euro in different sizes. Make sure the wheel is attached with nuts and bolts..
I drilled some holes to be able to attach the motor etc..
This shos how you you have two degrees of freedom. I used a drill to make a hole the size of the axle tube (that goes around the bolt and trough the wheel. This way the friction is very low and the whole thing fells solid..
I first finised the vertical movement control. The motor pushes down on the boom fixed to the central rod, that runs around the original axle.
I used treaded rod, a long nut and some clamps. This design can be optimized. Both the motor and the movig nut need to be able to rotate. If you fix the motor you need to use an extendable boom, like linear metal drawer runners (if you know what I meam).
I took a small L shaped piece and bended it 90 degrees to create the hing for the nut..
The motor is screwed to a thinner piece of wood using bolts that fit in the holes it comes with, and this in turn is fixed to a wooden block through wich I ran a hole so it could turn. I will look to a way to do this easier, and of course it is concievable you can replace the parts with a hinge to which you directly attach the motor.
More details of the block.
The treaded rod is attached to the motor using electrical connector busses. Nothing fancy, one could add a little nylon in between, it won't see much force or speed. Make sure it has the right internal diameter.
Here are the motor parts. If you can't use the screws to attach the motor you can use one of these things that go around pipes and use that to fix the thing.
The mirror is made out of styrofoam, which may be a good solution if it is reinfoced a bit more. It needs to be flat and one might smooth it somehow. Another option would be PIR (Celotex reinforced), but I haven't sourced that yet. Its stiff, hard, strong and cheap.
Here goes the horizontal actuator setup. I simply made another attachement to the turning part of the wheel, so it would end up lower. Then I attached an extention to the support pole and now I only have to make the connection.
This time I used a simple hinge to fix the motor.
The horizontal actuator rod is attached to the top moving part. It could all be sturdier.
Here a view from below. The horizontal actuator nut is closest to the motor, so this would be one of the extremes for horizontal movement.
It is nicer if you choose the wood sizes better than I did ;-)
Because this is one extreme postition it seems the threaded rod will touch the extention, but it won't
All set and ready for action..
Outsied on the standard..The mirror and standard need to be ruggidized, the controls still need to be attached.
Using styrofoam backing
Using a wooden backing. This still provides a good reflection at about 20 meters. I gluede the aluminium on with wood glue that I use for my boat as well. It does not stick extremely well to aluminium, but the surface is large and it does not deteriorate . With the right quality wood this combination can last for years. Putting a layer of varnish over the wood also helps.
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