The Frame v1.0
Contents of this tutorial:
Or jigsaw, circular saw, etc...
|6mm metal drill bit|
Or similar. You can make one easily from a protractor, string, and a small weight.
About 5 metres of thickish wood
Something like 4cm x 6cm. Exact lengths will depend on where you are in the world, explained below.
|About 3 metres of thinnish wood
Something like 2cm x 4cm. Again, lengths will depend.
|16 wood screws, about 60mm long|
|2 medium to long M6 bolts
Optional things to make your life easier:
The Frame is the most basic SolarFlower component, but its exact dimensions depends on where you are in the world. Specifically, your latitude, as this determines the angle of the sun. This is easy to find in various ways.
1: Type your closest city and country into this widget:
2: Go to Google maps, right click on your location and select 'What's here?'. You'll see two numbers in the location bar, the first one is your latitude. So, if for example you click on Madrid, Spain, and get the result 40.446947,-3.704589 then your latitude is 40.45 degrees.
3: Look at an atlas or something.
Axial mounted parabolic troughs, like the SolarFlower uses, are pretty forgiving with variations in the sun's elevation, so the angle you set it at doesn't need to be that precise. You can round your latitude to the nearest five degrees.
During the year the sun rises and falls in the sky by about 46 degrees. At the Spring and Autumnal Equinox the sun's angle equals your latitude. So if you're in Madrid, during that day the sun will be at 40.45 degrees from vertical. On the Winter Solstice it will be at about 63 degrees (40+23), and on the Summer Solstice it will be at about 17 degrees (40-23).
Making a seasonal adjustment setting for the SolarFlower is very easy, just drill two holes, and you can have as many settings as you like. Generally two is enough, one that splits the difference between mid summer and the equinox, and one that does the same for winter, if you're lucky enough to live somewhere with sun the whole year.
So, using Madrid as an example, you'd have one setting at 52 degrees (about halfway between 40 and 63), and one at 28. Around the spring equinox you set it to the summer setting, and at the autumnal equinox, winter.
The first thing to do is select the dimensions for your latitude from this drop down list:
It's important to note that because the sizes of your reflective surface and other parts will likely vary at least a little, these dimensions are meant only as a guide. Basically the frame needs to be whatever size will hold the rest of the device at the angles you want.
Some things to be aware of:
The main collector should be held high enough that it can turn fully without hitting the ground or any part of the frame.
It's best not to have the collector flat, as you'll probably be running some kind of liquid through the pipe, and it will need to rise as it heats. So if you're less than about 15 degrees from the equator just have the one angle setting and turn the whole device north or south during the year.
Take a section of your thicker wood, the length of dimension B in the image above.
To one end vertically attach with screws a second section the length of the dimension A, plus an extra couple of centimetres.
Drill the vertical wood at height A.
On the other side attach a second vertical with a spacer between it and the base wood. This needs to be placed so that the second bit of bike frame can be bolted to it at each of your seasonal angle settings. Feel free to place it later when you're attaching the Gearing to the Frame, to be able to see the best position.
Take a piece of wood long enough that your Collector won't hit anything as it rotates (about 135cm if your Collector is 100cm wide), and screw it perpendicular to the first base wood.
Diagonally brace the connection between these two lengths of wood. This can be with anything; a short length of wood, a triangle of plywood, a piece of metal, etc.
Attach verticals of length C to the inside of each end of the second base wood.
To the inside of the top of these verticals screw a piece of your smaller thickness wood, long enough so they can accommodate your seasonal angle settings, probably about 60cm.
Take a length of smaller wood long enough to fit between these two pieces and drill a 6mm hole in each end.
Drill your seasonal setting holes. Unless you've worked all this out on paper, the easiest way is to save this for when you're assembling the SolarFlower and directly measure the angle of the Collector with an angle level or similar.
Attach the cross beam with an M6 bolt in each end.
Drill a 6mm hole in the beam for the bolt which will attach it to the top of the Collector's copper tube. Keep in mind this will be offset from the center by some amount, depending on your setup.