The Collector v1.0

Contents of this tutorial:
Description

How to use this tutorial
Tools
Materials
Step by step instructions
Finalizing and tuning

What does it do?

The Collector is what receives the solar energy which you'll be using to run your applications.

How does it do it?

When a parabolic trough, like this one, is pointed directly at the sun it focuses any light which enters it into a line. You can then place something like a black copper tube at that focus, and pass vegetable oil, water, etc to carry that energy to where you want to use it.

How to use this tutorial

To view the animation to the left you will need to install Quicktime
There is also a YouTube based version, if needed, but the Quicktime version is recommended for better playback and control.

The best way to view the animation is to click and hold the time slider at the bottom and move it left and right to view whichever part of the animation you like, at your own speed.

You can download the animation here (right click, 'save link as'):
High quality (28.7 Mb)
Low quality (3.2 Mb)

If you are using a netbook or other small monitor, you may need to press F11 in your browser to view the page full screen.

Tools:

Bench vice
Power drill
3mm, 6mm metal drill bits
Jigsaw
Adjustable grips, also called Pipe wrench pliers, or Adjustable pliers
Hacksaw or Angle grinder
Hammer

Screwdriver

to fit your wood screws

Computer and Printer
Scissors, Scalpel, or Craft knife, also called an Exacto
Thick Sharpie, also called Marker pen


Materials:

Note: the dimensions given in this tutorial are assuming you'll be using two 60cm x 90cm aluminium plates, which is a standard but not universal size. If your reflective surface has different measurements you may need to adapt the lengths of wood used.

2 Aluminium lithographic offset printing plates or similar

These are pure aluminium sheets, usually about half a square meter by less than half a millimeter thick, used in a printing process fairly common with newspapers and magazines. A medium sized printing company may scrap hundreds of plates a week, so it's usually easy to pick them up cheap. They're pure aluminium, very reflective, and a nice thickness to work with.
If you absolutely can not get your hands on any (try, they're worth it), then stand by for an alternative version of this tutorial using other materials.

Compression fittings, or something.

I'd love to be able to tell you exactly what to use to attach the copper collector pipe to your applications, but it depends entirely on what you're going to be doing with the energy. Compression fittings are easy to work with and flexible in what they can be attached to, but are generally quite expensive. There are other options, but like I say, it all depends...

Whatever you use, you want a straight connection for one end, and a 90 degree (or elbow) for the other.

Future application tutorials will likely address this, and check the forum for what other users are doing.

Copper pipe

90cm long by preferably 22mm outer diameter, but anything between 18mm and 25mm should be fine.

Metal pipe

About 4cm diameter x 8cm long.
A section of bike frame would work well.

Hoseclamp, also called Hose clip

At least 3cm diameter.

Bike clamp ring

Most bikes have something like this, usually under the seat or handlebars. You may have to cut it free if it's welded on, and remove the bolt if there is one. Metal is best, as plastic may melt.
If you can't find one, use whatever seems like it would work.

2 pieces of 100cm x 48cm Plywood, OSB, or similar

Just needs to be something flat that you can cut with a jigsaw and probably should be reasonably rain proof.

4 pieces of 3cm x 3cm wood

The length should be a couple of centimetres shorter than the long edge of your reflective surface. Ie, if you're using a standard 60cm x 90cm aluminium plate your wood should be about 86cm long.

3 pieces of 2cm x 2cm wood

Same length as the 3x3 above.

32 Medium length wood screws
2 Wood screws, roughly 6cm long

2 M6 bolts, one roughly 6cm long, one 2.5cm long.

Get ones that are threaded all the way to the head.

2 M6 nuts

1 large Washer
 
 
4 pieces 3cm x 3cm flat metal

3 large plastic bottles

About 2-3 litre, must be clear and uncoloured.

Aluminium drinks can

High Temperature Black Spray Paint

Anything that says high temperature and is matt black should be fine.

Some kind of adhesive tape
5 pieces of A4 paper

Optional things to make your life easier:

Wood saw

Hole saw, also called Circle cutter

About 25mm, or a couple of millimetres larger than your copper pipe.

Pliers

Step by step build instructions

These relate to the animation to the left.

Step 1:
Download and print these five images (right click the link, select 'save link as'):

SFcollector_v1-0_middle.jpg
SFcollector_v1-0_middle_left.jpg
SFcollector_v1-0_middle_right.jpg
SFcollector_v1-0_top_left.jpg
SFcollector_v1-0_top_right.jpg

Make sure that they print out full size and undistorted, the box border should measure exactly 28cm wide by 20cm tall, like so:

2:
Lay out the five pages and tape them together so that all the lines overlap. The easiest way to do this is on a window during the day, so that the lines show through. It's important that this all be as accurate as possible.
Cut the red curved line with a craft knife or scissors, as accurately as possible. Discard the outer concave part.

3:
Draw lines from each corner of the plywood (or OSB, or whatever you're using) to the opposite corner, and from the middle of each edge to the point directly opposite.

4:
Tape the paper curve template to one of the pieces of plywood, make sure the centre and corners are lined up properly.
With a thick pen, mark the edge of the paper on the plywood. Be careful not to shift the paper.
When done, remove the paper.

5:
Carefully cut the curve with a jigsaw. Do not deviate by more than a couple of millimetres.

6:
Repeat steps 4 and 5 on the other piece of plywood.
Keep the template, it can be used to make further troughs.

7:
Take 2 lengths of 3cm x 3cm wood, and two of the 2cm x 2cm.

Screw the first 3x3 to each concave piece of plywood so that its top surface sits on the midpoint of the curve.
Attach the second 3x3 directly underneath it. This doesn't serve any structural purpose but will act as a counterweight.

Screw both of the 2x2s so that they sit on the point where the parabola curve meets the middle horizontal line, angled so that a face is sitting flat on the curve.
It should all look like this:

8:
Place your reflective surface in the trough so that their edge rests on the middle 3x3 wood, and they have a couple of centimetres overlapping the plywood on both sides.
Again, this tutorial assumes you're using aluminium lithographic offset printing plates. There is at least one other option which will be documented when available, but the printing plates are by far the best if you can get them.

9:
Screw the other two pieces of 3x3 wood so that the outer long edge of the plates is resting against them. You want that top edge as straight as possible, so make sure the 3x3 neither pushes it up from where the plate rests on the plywood, or allows it to sag.
Use two screws to secure, so that the wood can't twist.

10:
Take your 4 3cm by 3cm pieces of flat metal and bend them to a right angle. Drill two 6mm holes in one face of each, near the edges, and one 6mm hole in the other face, near the right side on two pieces, and near the left on the other two.
Screw each of these pieces to the corners of the convex pieces of plywood, so that they can be screwed to the top outer 3x3 wood.
If you don't want sharp screw ends poking out, wrap them in tape or similar.

11:
Cut a 3cm x 3cm x 3cm cube of wood and drill a 6mm hole through the middle. Attach to the convex plywood so that it sits just above the middle of the bottom edge.

12:
Drop the convex plywood into the concave. With a long screw between the aluminium plates, attach the 3cm cube to the middle 3x3 wood.
Screw the right angle metal pieces to the top 3x3 wood.
You want this connection to be tight, so that the aluminium can't slip.

13:
Drill a 6mm hole in the centre of the front plywood.

14:
Cut a hole in the centre of the back plywood, a couple of millimetres larger than your copper pipe. If you don't have a hole cutter drill a circle of small holes and carefully pop out with a hammer. It doesn't need to be particularly smooth.

15:
With high temperature black spray paint, paint the length of copper pipe.

16:
Attach your 90 degree elbow compression fitting (or whatever you're using) to one end of the copper.
For instructions on how to attach compression fittings, check an online guide such as this one:

17:
Take your 10cm metal pipe and make two cuts like so:

and then three more:

Bend the three bits on the end inwards by 90 degrees so that they overlap each other.
Drill a 6mm hole through all three as close as possible to the centre point of the pipe.

18:
Put a 2.5cm bolt through the hole, thread facing outwards. Place a large washer on the bolt, followed by a M6 nut. Don't tighten the nut.

19:
Bend out the two quarter circle flaps at the top of the cut pipe so that they can be placed over the elbow fitting. Once in place bend them back down, and attach firmly with a hose clamp.
Make sure the whole assembly is rigid and doesn't rattle or shift.

20:
Take a large plastic bottle, clean, and remove any labels etc.
Cut off the neck so that the hole is slightly larger than your copper pipe.
With a hole saw or otherwise, cut a hole just larger than the copper in the base of the bottle. Best if this is as close to evenly circular as you can reasonably get it.

Place the bottle over the copper, with the neck against the fitting. Be careful not to scratch the paint too much.

21:
Repeat with as many extra bottles as required to cover the length of your copper that will be within the trough.
For the last bottle, cut off the top and place over the base of the previous bottle so that it will sit a couple of centimetres from the plywood wall when in place.
As the bottles are heated they should shrink somewhat and seal their ends onto the copper.

22:
Place the end of the copper without the fitting through the hole in the back plywood, drop the pipe into the trough, and insert the 2.5cm bolt through the hole in the front plywood.

23:
From a drinks can, cut a 12cm by 3cm strip of aluminium, bend into a circle, and place between the copper and the hole in the back plywood. Bend up the corners so that it can't slide out of place. This is to reduce friction as the trough turns on the copper.

24:
Take a bike clamp ring (or similar) and secure with a bolt and nut to the copper pip, just above the aluminium ring.

25:
Attach the other compression fitting (or whatever) to the top of the copper.

26:
Place the third length of 2cm x 2cm wood on the front of the trough, so that its bottom edge sits 2cm above where the 2.5cm bolt pokes through. Cut little troughs into the wood so that the reflective surface can sit in them, and the wood can be tightly secured to the plywood.
Either that, or cut the reflective surface and bend it out of the way.

This is to stop the plywood flexing from the weight of the trough. If you're using OSB or something more rigid, you may not need to include this.

27:
Attach the 2x2 with a screw near each end in the concave plywood, and two closer to the middle in the convex.

Finished!

Email: solarflower.org@gmail.com Facebook Group: facebook.com/groups/solarflower.org/