I have already finished this project and I have 4 home made solar panels helping to power my workshop and house. The main problem with home made solar panels is keeping the solar solar cells in an airtight situation or they will oxidize and start to fail. I have come up with a very cheap and unique solution to overcome this but it needs many months of testing in the elements to ensure it works before I publish the details. I wouldn't want to encourage you and waste your time building something that has not been thoroughly tested. All I can say so far is that it looks good!
Heliostat sun tracker
This will be a simple piece of electronics that will move my solar panels so they will face the sun. There are many ways of making this, I initially thought of using 2 photo resistors or maybe use 2 solar cells facing slightly left & right of center & the one that produces the most power would indicate where the sun was. Plus if the whole thing was also solar powered it may need to automatically return to the sun up position ready for the next morning. It's early days for this project, I have a car wind screen motor that I could use to turn the solar panels but all these ideas will probably change as I start to build it.
Update, April 2012, I've successfully used the read head inside an old hard drive connected to 2 small solar cells, with a couple of relays and 2 reed switches and a windscreen motor this seems to work. But the wind screen motor is too fast, I've taken some small DC motors out of an old ink jet printer which may be better but I'm trying concentrate more on the evacuated tube project so this will have to wait.
Evacuated Solar Tube Technology (Completed 11/5/2013, click here for details)
Well, what can I say, these things are awesome, with approx 20 of them connected to your hot water cylinder incoming pipe you should be able to create all the hot water you need which may half my electric bill. With the wind turbine & solar panels & this, I may not have much of an electric bill at all.
So where am I with this, I have the tubes which are fairly cheap as long as you don't buy them retail, if you are not sure what these tubes are then there are many websites explaining the idea. But the general idea is to mount 20 tubes on your roof at 45 degrees into the sun & pass cold water through or near them & then back into your hot water cylinder.
What I haven't got is the raw materials to build the frame to mount the tubes, some 2 metre galvanised angle or box section would be good but it is expensive to buy it new. So if anyone can help out with some second hand metal framing for a small price then it would certainly kick start this project into action.
Update, April 2012, just picked up 12 X 2.8m lengths of 65 X 40mm rectangular hollow galvanised section, it's very light and will be ideal for this project, it came from an old commercial greenhouse.
Update, April 2012, just picked up all the copper pipe that I think I will need for this project, I managed to get 35 metres of 15mm copper pipe along with 30 metres of 3/8 (approx 10mm) copper pipe. It was all second hand but it had never been used! The 15mm pipe will circulate the water from my hot water cylinder to the evacuated tubes on the roof and back down to the cylinder. The 3/8 tube will be used to make the heat transfer pipes that sits inside the evacuated tubes.
This project is almost ready for its own page, I have already completed 5 heat transfer pipes and I'm currently testing them. The results are amazing and enough to get me very excited about this whole project.
The evacuated tubes can not be made they have to be purchased, if you shop around or perhaps import them from China then they can be very cheap, any where from $10-$30 NZD each. They comprise of 2 glass tubes, one inside the other with the rims welded to each other with a vacuum in between. My tubes are large commercial ones and are 1.8 metres long so 20 should be plenty for my needs. The inner tube has a heat absorbing coating which absorbs the heat from the sun without losing that heat because of the vacuum.
The heat pipe is a sealed copper tube containing a liquid with a low boiling point, in my case I'm using acetone, this heat pipe is then placed inside the evacuated tube and the acetone heats up into a gas and the heat is transferred to the top end of the pipe where it transfers it's heat to my domestic hot water and then it cools and turns back to a liquid on it's way back down to start the process again.
The tests I've done so far have been extremely successful, within an hour in the sun the end of the tube can reach 100°C (212°F). These temperatures and associated pressures are very dangerous and are only obtained during testing, if the end of the heat pipes were connected to the cold water flowing from the bottom of the hot water cylinder then these temperatures would not be possible. I'm currently testing different amounts of acetone to find what works best but it is likely to be around 13ml for the size of tube that I have. This whole process does have a dangerous side and adding too much acetone will lead to the copper heat pipe exploding so be warned, learn from my mistakes and results so that you don't have to go through this part, I'll publish the exact details as soon as I've completed the tests.
Had some time today to do a bit more on this project (May 2012), today I machined and completed the top and bottom rails of the metal frame that hold the evacuated tubes. The rails comprised of lots of 64mm holes in the top rail for the tubes to pass through and lots of cut outs on the bottom rail for the bottom of the tubes to sit in. I will publish the pictures and more details when I'm a bit further into the project.
Early June 2012, the frame is complete and the next stage will be the copper manifold.
Peltier & Cooking Oil Fuelled RC Car
This idea has been in my mind for a while and I'm not sure it's even possible but what I would like to try is to buy a cheap radio controlled car & replace the batteries with a peltier device.
A peltier device is a bit smaller than a match box (or the ones I will use will be that size) & half the thickness with 2 wires coming from it. If you connect the wires to a battery it will get very hot and if you transpose the wires it will get very cold.
But what is not often known is that if you have a temperature difference between the 2 sides it will create a voltage. It is this power that I would like to capture by surrounding a burning cooking oil flame with peltiers.
But for these things to work well one side needs to be cold & the other hot so I may need some sort of cooling on one side, I'd really like this to be water cooled because it sounds like fun but that may prove to problematic, a laptop processor cooling copper heat extraction assembly might work.
However I make it, it will be an interesting project, I've ordered the peltiers which are very cheap but they haven't arrived yet.
Update, the peltiers have arrived, a quick test with a candle showed an almost instant output of 0.5v for 1 peltier. I had ordered 10 of these so this would seem to be plenty of power. I really should state that this would seem to be plenty of voltage, I've yet to ascertain if the current and subsequent power is enough as i have no idea of how much I need. However what this test does give me is an idea of what voltage RC car to look out for, something with 3 x AA batteries should be fine.
I've also had some more ideas on how to easily keep one side of the device cool, I'm now thinking of 1 tin can inside another with water between the 2 and the peltiers fitted to the outside of the inner can, strapped on with a cable tie and lots of thermal paste. This is just an idea for now but this approach seems simple and cost affective which covers the top 2 of my 'must have' list.
Programmable Robots & More (Completed 28/4/2013, click here for more details)
I've always liked the idea of building a robot, one of those robots that can move around whilst avoiding it's surroundings. The way to make these are to program a chip that will output commands depending on various inputs that it receives. Such as an infra-red sensor to sense a wall ahead which the chip will acknowledge & tell the motors to reverse etc etc.
This would be something new for me & an opportunity to learn a new skill, to be honest it looks fairly easy but that is generally the response of someone that has no idea of what he's doing!
There are many ways of programming a chip, the method I will probably use is by using an Arduino board & programming this via USB to a laptop, this board connected to a few sensors, servos, motors & a way of controlling those motors is the core of this project. The mechanics is just the fun part.
If anyone knows of cheap parts then please let me know, I'd like to make all the boards myself if that's possible.
Combining Projects---- Peltier & Cooking Oil fuelled programmable robotic car
If I can get both the above projects working then combining them may not be too hard, a voltage regulator and lots of luck and perseverance should be the key.
A Digital Torpedo Timer
I've already built a fishing torpedo with a mechanical timer which has worked well but what I would like to build is an electronic timer. This shouldn't be too much of a problem & because I already have a mechanical timer this project is low on the to-do list. I would like to stress here that my electronic skills leave a large opportunity for improvement but something this simple can be found on the internet & copied or adapted without too much electronic experience. Or at least that's the plan!
A small project with great results, I made my first potato powered digital clock. OK so I bought the clock & I certainly would not be the first to power something from potatoes. But it captured my imagination & I love the whole idea. It's free power, it's almost magical when you connect the potato & the clock springs into life.
I used to have a shop bought kit when I was much younger but all I can remember about it was that the potatoes used to dry up & shrivel & it would struggle to keep going for a week. So my goal was to make something that would last longer & look good. I think I've achieved both these things, the first clock is on test & still going after 2 weeks & 5 days & keeping good time. I will eventually make a small batch of these & add a complete page to this little project, I think they are a good learning tool & a great introduction to science for children. If I can keep the price to around $20 then I may even sell some!
I've made a torpedo so now it's time for a bomb, I wonder if this has just triggered the FBI computers to flag up a terrorist alert. I hope not because jail time would lead to many problems when trying to complete these projects. I guess if I was in jail I may not have a need for most if not all of these projects.
OK, enough of all this nonsense, back to the serious stuff. A bath bomb is a tennis ball sized bunch of chemicals that when placed in the bath it will fizz & fall apart giving your bath all those lovely smells, colours & water softness. It's not really my thing but my wife loves them.
I've got all the chemicals & all the other bits that I need but some of the other projects have caught my imagination so this project has been shelved for now.
Beer Bottle Candles
I've come up with a method of cutting beer bottles like Corona in half, with a bit of grinding they make great glasses, I made some of these to sell last year with all money going to the NZ Earthquake appeal which was a very serious earthquake in Christchurch New Zealand in 2011. Since then I've tried filling these with wax, adding a wick, and creating cool candles. They look really good and they are a great talking point at parties. For such a simple idea it does have many problems that I have had to overcome. I like the idea that I'm recycling old beer bottles plus I'm also recycling the end of used candles that I get from local restaurants who would normally throw them away. To be honest the whole project has been a great manufacturing success but for some reason I haven't carried it on to the selling part, the fun part was making them. Maybe one day, but I'm going to build that robot thing first. Update April 2012, these glasses are now on sale via their own page on the website. Although I still haven't finalised making them into candles just yet.
Sterling Engine Power Generator
I've just made a very cheap and easy to build Sterling engine and I have an idea of attaching magnets to the fly wheel and with the aid of a copper coil I want to try and generate some power. It will not be much power but some of these little weekend projects appeal to me. Actually this would probably be a week of researching every evening and just the weekend to build it, but even so it appeals to my sense of adventure.
I had an hour to spare today so I hooked up the sterling engine to the shaft of a small DC motor from an ink jet printer and wired the motor to an LED. It kind of worked, it generated enough power to illuminate the LED but the engine wasn't fast enough to keep it lit so it ended up flashing on and off. I've given the engine to a local school so I'll have to make another one before making any further tests, but it's the evacuated solar tube project that I really want to start on first.
I recently saw a TV show where they tried to make a hovercraft, they were unsuccessful but I like a challenge and I think I can do it much better. Since the show I've had more time to reflect on all the difficulties this project entails but I haven't given up on it yet. A single seater with 2 lawn mower engines and lots of polystyrene and fiberglass would be a good place to start, how hard can it be!!
I picked up an old lawn mower and got it going, tarted it up a bit and sold it. It's not what I intended but I repeated the process again and I now have another one for sale! Well at least it helps pay for some of these projects.
Segway (Completed 17/3/2013, click here for more details)
I've recently been looking into making my own self balancing 2 wheeled transport similar to a Segway. I had a go at riding on the real thing a couple of years previous and it got me wondering whether I could build my own but I'm still unsure if I can keep the cost down to an acceptable level. I'm sure that I can build one with a couple of DC motors, motor controllers, accelerometer, gyro, micro controller and batteries for less than $1000 but anyone can make something if they throw loads of money at it. The hard part is can I make one for $200-$300 out of scrap. There are a lot of unknowns but I already have some small 12v batteries and I have 2 electric golf trolleys that potentially I can use the motors from although I have not checked. If anyone has any 12-24v DC motors then please contact me, something from an old wheelchair would be good including the wheels, axle & mounting.
Update October 2012: I checked out the golf trolley motors & they are not even close to being suitable, then I went looking for wheelchair motors. There are loads on Ebay but the shipping is too expensive to get them to New Zealand. In the end I managed to buy an almost complete wheelchair for $200 NZD, at least it has the 2 motors, gearbox & wheels. I have a few of the technical items ordered so when they arrive I will make a start on this project some time this week.
As usual I will document the build each day & publish the progress at least twice a week. I've amended my cost goal to a more realistic $500 NZD, mainly due to the cost of the motors & the cost of the high current motor controller
Paper Briquette Maker (Completed 2012 but I have not yet documented the details)
It's winter here in New Zealand and I needed a simple project that I can make inside when the weather is not so good. So I'm thinking about making a paper briquette maker. The idea is to compress wet newspaper into a brick shape and once it's dry to then burn it on the fire.
I have a simple lever idea in mind but I wanted to design an easy method to release the brick afterwards, so far I haven't come up with a simple solution. There are some retail versions out there but they look far too slow to operate, I want a design that can easily and quickly make the bricks, if it takes too long or needs to much effort then the thing will not get used.
To be honest I really wanted to make a log splitter but the hydraulics and rams, hoses and controls were just too expensive so a paper briquette maker is a poor mans second choice.
I've now completed the briquette maker and will create a dedicated page for it soon.
Crypto Currency Miner
This looks like fun and it generates free money, well...apart from the power usage, but if the currency goes up in value then this is something i will definitely make.
If you like our site then please click on the Facebook icon at the top right of this page, thank you.
For more information you can email us via our Contact Us page.