Electric Sculpture

Model of the SS? Why don't you scale the time as well ? I can fall asleep in 8min

Ha you found us then!
The problem is two fold, the mechanics and the electrical/electronics...
Hopefully some of the guys will have ideas for one or t'other aspect.
I've got no real experience with any dynamos, but hopefully there are some 'off the shelf' bits which someone can direct you too.
Tell the m there's a reward, tins of tuna or Gooz cards* usually work

Del
_{(A petite in joke from Hendrik ... Get Out Of Zimbabwe free card...)}

I'm either just dense, or dont get it cause i'm on the wrong side of the pond... 8:33.... 18....

What is it?

I know. I'm going to obsess on trying to figure it out. If it "comes to me", I'll let you know.

Bit pushed for time at the mo' - but I'll try to get back to you later.

Hi Guys, . . its a map of the solar system laid out across the park. . at a scale of 1:8,000,000,000. The position of the sun is marked by a sundial. I want to put a wheel around the plinth of the sun dial that people can turn to generate electricity. This electricity will immediately light up the scale model sun (75mm in diameter) which is part of the sun dial - and then - if the wheel continues to be turned - 8 minutes 33 seconds later, the site of the earth will light up too. . . and thats it! somehow I need to connect the turning wheel to a dynamo, hidden inside the plinth, which can then deliver power to both the 'sun' and 8.33 mins later - the 'earth'. Is there any existing components that happily fit together to create this?

Wow! that was going to be my guess for sure.

Soo.. it should have been the 8:33 that gave it away? Must be the time it takes for light to travel from sun to earth?

Interesting project.. I'll have to re-read it and think about the actual problem, instead of the application.

Hi gaiamere,

The first thing that I thought of was the time it takes for sunlight to reach the Earth. However, when I did a search, the average time was 8:18, so it threw me off. Where is your source for that number?

By the way, it sounds like a really great project! Would you consider posting your progress with pictures and such? I know most of us would like to see it. You could even contact CR4 admin. and start a blog here.

Mike

Yes, I second the Blog idea. I would definitely enjoy seeing/reading about the progress, especially if it were designed by a group of CR4er's. You have my vote.

Well, if you are a friend of Del's then your a friend of ours.

However I've not yet guessed what it is you are designing.

If it is a seesaw walkway for a translight tour at the pivot points the generators could turn, but then you would need to throw in some batteries to smooth out the irregular traffic to achieve this timing you specify.

Ain't much in this world that is really vandal proof, but 57 or so feet buried in the ground ain't all that difficult for wires, and so far it doesn't sound like you're calling for a lot of power. It also sounds like DC is the type of power you are wanting to work with.

You may find all the stuff you need in a Granger, or McCallister Catalog.

There are hand torches with dynamos you can use with a rechargeable battery also present in the torch. The whole costs about 10 to 20 £. LEDs are as well I think 3 of them for each torch.

If the generator is too small you can use several in parallel.

Del who is an electrician ( I have the feeling he wrote that once) could give you hints how to make a timer and connect it. I am sure he will be delighted to do it.

Does it all have to work only from the electricity generated by the turning? What happens if the motion stops - does it reset the timer? Are the "Sun" lights also lit by the movement? What kind of budget do you have (£10, £50, £100 ... or what¹)? Are you OK with the mechanics? Lots of other questions, but I haven't thought of them yet?????

Please spell out what your ideal is - write an essay if needs be - then we can all have a good long think.

¹ Must emphasise that I'm not after your dosh - but we need to know roughly how much there is in the kitty _{^{(sorry, Del!)}}

Yes it does have to work only from the electricity generated by the turning. If the motion stops then I guess the lights go out, unless theres a way to store the power in some kind of battery, which might then allow the lights to stay on untill the battery is dead . . . Yes the sun is lit by the movement. The sun lights up first and then the Earth lights up after. Budget is what it needs to be - if we can put this together, reliably, then it can be paid for - how much do you need to design it for me? what do you mean "am I ok with the mechanics?

" ... how much do you need to design it ...?"

I would not charge anything - assuming that's the way you meant it. The first few times I read it, I thought you meant " ... how much do you need to design it for me? ... " - as in "How broke are you?". Then I thought "hmm - I don't actually need it - but maybe want could replace need to make a better fit". Then I thought "Hell, I need to design this like a hole in the head - I've been working my bits off for the last nine months ... ".

I would like to help. You've answered some questions, and asked some more. I'll send you a private message tomorrow. G'night, John.

Depending on the diameter of the wheel, you can directly run the dynamo by edge friction or add a speed increase gear train to increase RPM at the dynamo. Models are available on the market with a rechargeable battrey option.

A simple 555 IC timer will do the timing. No body will check the accuracy. Do you reallythink that the viewer turning the wheel is going to remain on the spot that long? It may be a better idea to use a tracking Laser LED from the sun to light up the earth analog straightaway. This is also vandal proof as only light and not 18 meters of wiring runs from the 'sun' to 'earth'.

Pleaase check out these:

http://store.sundancesolar.com/leddybili.html?productid=leddybili&channelid=FROOG

http://www.nordicgroup.us/s78/dynamo.html

http://pilom.com/BicycleElectronics/Dynamo.htm

http://blog.makezine.com/archive/2007/03/nofriction_bicycle_dynamo.html

Bioramani

For a generator maybe a bicycle generator that rides on the inside of the wheel. You might need to fit a rubber wheel over the steel wheel of the generator. It could contact the inside of the outer wheel. ^{_{Sorry about all the wheels!}}

I'd go with a small battery, for the lazy ones, and a timer circuit. You'll need to start the timer as soon as some generator voltage threshold is passed and then turn everything off, at some point, and get ready for the next demo.

I'll throw this out and ponder.

Lyn

I'd start with one of the dynamo LED camping flashlights (as mentioned above) similar to this one...

http://www.campingcomfortably.com/coleman-stormbeam-dynamo-flashlight-.html

then build a simple little delay timer circuit. The batteries would allow tens of minutes of LED power for 1 minute of cranking.

If the batteries are unacceptable, there are "supercaps" which could supply a few minutes of LED power...

http://en.wikipedia.org/wiki/Electric_double-layer_capacitor

I think this project is able to incorporate more sophisticated generators than hand cranks.

"I want to put a wheel around the plinth of the sun dial that people can turn to generate electricity"

Even a single gear driven generator is implied.

I agree with batt/timer circuit.

A DC motor of the right specifications will work nicely to generate power with a bridge rectifier, (won't matter which way the wheel is turned) with a set of plastic gears to provide the speed up of turns, either a battery or large capacitor could store the power. A CMOS oscillator with on-chip dividers can provide the time delay with simple transistor drivers for the LEDs. Most of this stuff should be found at surplus stores and not cost much. A voltage regulator may, or may not be needed. With the right motor/storage, probably won't need more than 30 seconds cranking to charge the system.

How about the primary source of illumination of sun and earth is 'line current' of 110V?

So that the illumination could be big and bright and not limited by tiny generator.

Limit switches and timer could be included for triggering the illumination at sun and delayed illumination at earth etc.

I have two suggestions. First, I assume your audience includes people of all ages and strengths. Unless the direct and exclusive conversion of motion to electrical energy is the whole point of this design, you may want to consider storing a surplus of energy and having the lights go out based on a timer and not depletion. You could still require a specific amount of time or cranks before the lights come on, regardless of the available energy. In this way the stronger individuals would create a net add to the stored energy and those less able would create a deficit. If a school bus full of small children came by they would have a problem, but that's bette than every small child having that same issue.

My second suggestion is that you check out eBay or one of the industrial supply liquidators someone mentioned, instead of Grainger. The amount of surplus, refused and abandoned inventory flooding the market these days is sad but remarkable. You should have no trouble over-designing this thing if you know your way around eBay.

Have fun!

Just had an idea.
Maybe a local Further education college or school may be interested in doing the electrical/electronics as a project for CDT (Craft Design and Technology)?

Is the main problem, design, build or both? And is it mechanical or electronic/electrical?

Doing a paper design wouldn't be too hard, or even building a working mockup.... but a full vandal resistant mechanical design/build could become very time consuming.

Lets see what we have so far

Generator.... LED wind up torch seems like a good bet for quick experimentation.
Rectifier/power supply to give some sort of regulated DC..... any offers of a suitable target voltage? 5, 9, 12? Dunno what the hand cranked gererators put out...
Delay/timer A simple 555 timer ship would do it, comercial timer modules tend to be mains operated and we want to keep it low voltage DC.
Mechanical design... hmmm my crystal ball is clearing...I'm seeing stainless steel...lots of stainless steel...
The ball is clouding over...please insert another £1 coin/piece of tuna
Del

Hi there, I've just found this thread and thought I'd add my twopenn'rth.

Transcendian's idea about contacting theatre / lighting bods is good, but may cost. I thought I'd expand on Del's schools idea:

A good way to make contact (as you're an unknown to the school) is via the School Engineering Ambassadors (SEA) - both the Institution of Engineering and Technology (IET) and the Institution of Mechanical Engineers (IMechE) have programmes to get engineers into schools and enthuse the pupils / students. Both of them are UK institutions: the IMechE are at No 1 Birdcage Walk (near Green Park) and the IET are on Savoy Place.

The IET operate the SEAs through SETPOINT (click here) and the IMechE through STEMNET (click here).

They would be able to put you in touch with a school / college that would want to be involved in the technical design project - with help from the teachers and the local SEAs. Generally on a local basis, IMechE / IET members work together, even if the two institutions are sometimes at loggerheads...

The added advantage of going down this route is the level of publicity you would get for the finished installation - it would be covered by the Institutions and the local (national ?) papers will love it. As it will show the institutions in a good light (engineers of the future, collaborative projects - all good buzz words), they will be happy to help with the PR.

Good luck - keep us informed. If you need help contacting the IMechE or IET, drop me a PM - ask Del to - and I'll see what I can do.

I would use a treadmill motor ,you can get the whole treadmill for free and there are lots of parts and some have timers . they all have rollers and many A/C electrical parts . i have built a hand crank generator from one for 12V LEDs and it only takes about 8volts to light them and that is hardly cranking .I hooked one to my electric boat motor and it worked but I need a bigger pulley to make it go faster .

You're talking about a few LED lights, which don't draw very much power. Since this sculpture is outside, how about abandoning the generator idea, and incorporate a small solar panel. This would charge the batteries and then you just need a timing switch. It could function all night on it's own from the batteries. It's just the switching issue that comes into question.

Oh My! . . thank you all so much for so much mind-boggling information . . . . but there's been a change in the spec and now, for this particular installation, there'll be no dynamo or moving parts or sundial. (shame) . . but lights would still be needed. Someone suggested solar powered lights that come on in response to touch or movement. That would be good. Could we have the Sun (now a circular glass surface in the ground) light up when someone treads on it or touches it? Once the Sun is switched on in this way, can the Earth still light up eight and a half minutes later? When the Earth is also shining, perhaps both the Sun and the Earth should remain aglow for a given period and then both switch off together. After the two switch off simultaneously, the system would remain dormant (or without lights on) until someone touches it again. Then the entire sequence would be repeated. Can we make this happen?

Eight minutes is a huge amount of time: you really have to take on board Wiz's suggestion of multiple lights showing the light moving from the sun to the earth. Then when the Sun goes out the lights should really go off in sequence at the same rate: if the sun went off now it would be 8 minutes before we knew anything about it.

I dont understand that

What Randall was proposing is that when the Sun goes out, the lights I proposed (between the Earth and Sun) start going out, starting with the Sun and going out as they approach the Earth. An interesting effect.

The first point is that 8 minutes is an eternity when your just waiting for something to happen, you have to find a way to keep people interested (showing the light "propagating" from the Sun to the Earth is one way of achieving this; including Mercury and Venus as intermediate milestones will help).

The second point is that just as light takes 8+ minutes to reach the Earth: so does dark. If you show the earth lighting up a while after the Sun, then you should show it going dark a while after the sun.

Other people have mentioned this, but, I think it's worth repeating: have you ever tried to see which one of your headlights has failed during the day: even powerful lights which provide a lot of illumination at night are almost impossible to see in bright sunlight. You will find it very difficult to "harvest" enough energy to power lights bright enough to be seen during the day.

Time and money can fix many a problem.

We have the technology!

I have started to wonder though if you will get the effects you want outdoors during the day with low powered lamps and lights.

In motion picture production there are a few sayings common to the industry: "Script to budget, or budget to script." - Another is: "It costs what it costs, and takes what it takes." - Another is: "If you think a professional is expensive, wait till you hire an amateur."

Several in this thread have questioned the efficacy of the 8 plus minute delay from one sight event to the other. Possibly you may consider 8.5 or so seconds as a "scaled" event time to enhance the dramatic impact, and have it go in a repetitive manner.

Who is the Director here?

As much an artist myself, I do things my way when in that position, and you either like it or you don't.

In the position of a "Technician", well that's different story: pay me and I'll make it happen according to your vision.

One time working with a Grip, when I was the Gaffer (Chief Set Electrician) the Key Grip was overcomplicating a rig to the point where I was prompted to say, "Archie, you need to get a divorce from this rig, it ain't working out."

Typically your audience, hardly cares about the technology used to create a "show".

Still photographers use slaved strobe lights that use capacitors to achieve a great deal of light in bursts that off the shelf may well suit your needs.

Motion picture guys use Hotlights.

Combining those most simply may well mean you ought to get a divorce from the source of power for them, and determine first what lighting makes the show work, then determine how to power it, and then throw in the necessary control devices.

Yes, your changes pose no technical problem but do make things a little more complicated. Trancendian is correct, we should determine the lighting demands and then work backwards from that. Solar is likely the best solution with a lead acid battery, although Lithium can certainly be used but they are very picky about charging methods. A touch or pressure switch (in the case of stepping on it) can be used, again, timing with the proper circuits is not a particular problem. If you want to use the same 8 minute plus layout, my earlier suggestion would help keep attention focused but that is up to you.

Depending on the lighting load, either a low dropout linear or switching regulator should be used, personally I would prefer linear.

Is the current proposal all the details known at this time? High brightness LEDs have an efficiency of about 32% and generate heat, lots of heat. More conventional LEDs have a bit lower efficiency but generate less heat. Are you planning on using this display during daylight hours or just dusk to dark? This will determine how much brightness you'll need to be effective. More questions to follow likely.

Someone has already asked - but it's quite important - are the lights expected to be discerned in daylight, or only after dark?

People are only in the park during the day. Those in the park after dark are intruders or attending the occasional event.

where are you?

Gaiamere, I am in the USA, western Colorado to be more precise. That may or may not be a problem for you. I am six time zones away from you, in the mountain time zone. Ask any questions you want to, you can click on my 'Electronic Wiz' symbol to send e-mail off of this forum or I can send you my direct e-mail link. I would definitely understand trying to find someone in your own 'backyard', it can be a bit difficult communicating by 'wire'.

Sorry, we here on CR4 sometimes forget that we are not always talking to others in the 'know' and get carried away.

Running this project in the day time will up the power demand some, bright light comes at a cost unfortunately despite the hype about 'new' sources.

I would like for someone to investigate this gentlemans devise. Several papers and models have been built and it would seem that it would be a interesting platform for a kinetic energy 'art' platform..... please check this out.

http://www.veljkomilkovic.com/

I'm not even sure I understand how to follow the conversation here on this blog. I think I may be barking up the wrong tree here - or simply barking! The question I am asking is " Is there anyone out there who can definitely help me design and produce this piece of kit?" - then please do step forward. If I am supposed to understand everything that has been said to me and find my own way through all this information I am receiving and construct the blessed thing myself - then could someone please confirm that to me? Can anyone speak to me on the phone to progress or even resolve this dilemma? Can anyone nominate a company or an individual who can possibly work with me to produce this? I am not conversant with any of this technology discussed. I am simply looking for an individual or a company - preferably in London, who can design and build this kit, for a fee to be agreed. I am hugely thankful for your time and respectful of your knowledge but I think we are not really understanding each other here and I am thinking I'm a bit lost and will explore a different avenue - .

I couldn't help you from where I am any more than I have. My passport is expired, and it would take a good deal of money and time for me to re up my passport, travel and visit to supervise.

(17 grand and three months might work with expedited renewal of my papers.) You'd be better off calling Shepardon studios, or going online and looking for London Production Services, or in person showing up at a Theater and asking a stagehand to point to a Lighting Director.

London has a long tradition of technical achievements in Theater and Lighting.

My dear lady, you are in London, or nearby. If you are lost it is because you have decided to be lost.

Although I would enjoy working on such a project, the logistics (~5800 km) and cost would not be reasonable. I'm sure you will be able to find several talented local resources to assist you.

A few comments... IMHO:

The concept of realism by delaying the light on/off ~8 minutes to reach Earth is good one. I like it! However, in this day and age of instant gratification, web capable cell phones, and attention spans measured in seconds, I think your target market will probably leave the site long before the light makes it to Earth.

If the ~8 minute delay to Earth is critical, I think that adding a series of spaced lighted markers in the ground to show the light progress AND the addition of Mercury and Venus scaled planet markers would help to hold the target audience attention (maybe).

OF COURSE this dramatically increase the complexity and cost of the project!

I think a properly scaled model of just the inner solar system alone (with no lights) would be a worthy project by itself. Especially if the main audience is there only during the day. A lighted project will have to be over-built with night time vandal resistant features (sadly).

My best wishes on your project!

If one is standing at the "sun" it will twice as long for the reflected light from earth to reach the observer at the sun.

As I have said in #1 I will fall asleep in 8min.

Why not have a digital timer counting and displaying the seconds in quick time giving the effect that it takes longer.

For generating power you could use something like a dynamo on a two stroke engine with a lot of strong (super) magnets added in the rim.