When I was a kid we had kits for entire computers, radios, modems, test gear and stuff.
What happened to that?
Not impressed with flashing LEDs on string.
----
Edit: Add a rant as people seem to miss my point:
Well all the kit companies disappeared as people learned to assemble prefab stuff and purchase ready made consumer electronics made by the lowest bidder.
I'll probably get downvoted for this but...
My real problem is that people want a quick fix now rather than actually learning something or constructing something of complexity. About all you get now is someone plugging an LED into a prefab arduino and crudely hacking together some prefab C functions and it's the next best thing since sliced bread, requires a whole blog about it and much circle-jerking from the maker crowd about how this is the next greatest flashing LED contraption.
Put a 555 or a couple of transistors, capacitors, resistors on the table for a simple astable multivibrator and bricks will be shit. Even the basic maths for working out which resistor has to be used in series with an LED to limit current has to be canned in an iPhone app these days.
This is a cult of people assembling Ikea furniture, no more.
Hard as it may be to believe, there's a difference between things that don't interest you personally and things that are junk. And the existence of things that don't interest you somewhere does not automatically mean that everything there is crap.
Don't see the sort of kits you like being made? Join us! Innovate, and design your own!
No, its grown, quite a bit, and only heathkit has gone away.
There's much better stuff out there than when I was a kid and all we had was heathkit. However you need to use the internet, not just the annual heathkit catalog.
Something along the lines of the pie used to have basically one very big slice, which went out of business in '92, and since then the pie has expanded quite a bit, although no individual slice has come close to the size of Heathkit before it sank... the small size is probably why the individual companies are growing instead of shrinking LOL.
Tons of kits like this still exist now a days if you are into guitar playing. kits to build copies of long defunct pedals, or old school tube amps. a lot of fun to make your pedal board, and you can learn as much or as little as you want.
As a kit I cut my teeth on building a hero 1 robot from heathkit before I even learned to write cursive. I often tell people that just to up my geek cred. Luckily the drive to do nerdy things has never really left me.
Hey, there is a project going on that is much like you'd like. I took my 12 year old through it, and it's a bit rough, but not bad for how cheap it is:
Oh and a calculator. Any old cheap scientific (Casio/TI/HP) will do as long as it doesn't make errors.
The big problem for me was the maths initially. It doesn't take long before you hit a brick wall at the age of 12. My 10 year old daughter is learning algebra and programming (in python!) though at school so things are looking up.
What is important to note in these kind of scenarios is that in most cases the "signal level" does not decrease. So the increase of "noise" is not that bad of a thing, it is usually quite trivial to filter out, and there is always something/someone useful popping out from the noise too.
In general I detest the kind of attitude you represented in your parent comment, eg people shouldn't doing something they enjoy just because it doesn't meet your standards.
Actually that's a pretty large misinterpretation of what I said. Conclusively:
People should still do this, but stop turning it into a cultural movement in which everything unremarkable is remarkable and knowledge is abstracted away into insignificance. The knowledge is infinitely more important than the abstraction as the abstractions come and go.
For an extreme example: When playing around with electricity that knowledge and those fundamentals can and do make the difference between life and death. Some maker contraptions that I've seen that flash lights connected to the mains are so dangerous it's unreal.
I've thought the same thing for the longest while. I love that people of all ages are starting to learn about electronics & firmware. At the same time, the desire to build something sophisticated has people skipping large steps and as a result, build insanely complicated systems that a little knowledge would let them do in a much simpler fashion.
They're learning, but with enormous gaps in knowledge.
Yeah, sort of agree. I found myself wondering, whats wrong with ye olde bread board? And then, like you say, kits, which we can easily still buy.
But lower down I saw their ideas about using this kit on paper or material, and what not. Which does seem more like craft materials than education, but also educational. So, I'd suggest this kit is a way in. It can get people, kids, interested, and once "hooked" they can then get all bread board about it, then wield a soldering iron in anger.
So, really it depends on how this stuff is used. Any one using this as an education tool would need to sort of spot the talent, and quickly move them on to something a little more educationally useful.
Interesting idea. Needs logic gates? I find the idea of a gate level ALU sew into a sheet of fabric to be intriguing. "My bed quilt is a working 8x8 hardware binary multiplier".
A game of life automaton in the form of a bedquilt would be interesting.
These strange ideas would seem to be a logical extension of the basic product concept.
I don't want to multiply numbers, I want the gate level circuit diagram, preferentially each individual gate having an LED at its output. Then feed in random binary numbers and watch the show.
Kind of like if I want to know what time it is, I'd look at my phone, but if I want to look at something cool on my wall I'd look at:
I've seen several preorder strategies in the recent electronics kit field.
The P112 project did a kickstarter. Mines sitting on the bench, too many other things to work on. A very simple kit given what it does. I'm sad I had to wait like 4 months for someone else to put the SMD components on, I could have done that myself in less than an hour.
The N8VEM people sit on preorders until they get 20 at a time. Sometimes thats a very short amount of time indeed like days, sometimes its a bit longer like years between orders of certain obscure PCBs!
The SpareTimeGizmo people have done some ship off the shelf and some preorder, I think? I was fast on the draw and got one of the last 6120 PDP-8 full kits ever made some time in the 00s.
The KB9YIG SDR people were supply line limited at a very low price, so as they put together sets of bargain price kits they put them up for sale and usually sold out in an hour or at most a couple hours. To say this aggravated people who missed the 45 minute sale window, every time, would be a profound understatement. They switched to a much higher price and off the shelf shipping a couple years ago. I miss paying $11 for a single band fixed freq SDR although its annoying to pay $21 today for the same thing, its nice that its always in stock rather than being something like a lotto.
I wondered the same, and it's actually answered on the page:
Why is our funding goal just $1?
Chibitronics is an academic research project. The work to develop this technology will proceed whether or not others would like to participate in our research project. Although the circuit stickers featured in this campaign have been produced in small volumes, they were produced using techniques suitable for mass production -- we are "prototyping in production". If just one person backs this project, we're still perfectly happy to build and ship a single unit, yet we have the process scalability to meet virtually any demand.
It's a bit weird, but I guess they're using it basically to measure demand and size the initial order(s).
What a great idea! I would immediately buy this, I just wish this were an actual product instead of a crowdsourcing kickstarter-type campaign.
After my experience with Lockitron, I have no desire to lock away my money for months while fretting over whether or not I'm going to get ripped off.
The same goes for the Heritage Chemistry set which I would buy for any of my kids (but to be honest, mainly for myself), but I just don't have any faith that I will see my $500-700.
One startup idea which is either commercially nonviable (sounds likely) or is new, would be a startup which is basically a consumer level online internationalized purchasing department.
So if you define a project called "teach my kid titration" it would understand how to get phenolphthalein and other indicators in Belgium, how to get a beaker in Texas (good luck), etc, and for a modest 10% fee of which they keep half and the designer keeps half, they make one CC charge and magically anywhere in the world boxes start arriving.
This would be tremendously helpful with electronic projects, where I get a custom PCB from somebody, some obscure transistor from somewhere else, and COTS support parts from the "big 3" suppliers.
Something tells me the agony of being a purchasing agent can't be abstracted away for a mere 5% commission. And how to intermediate, if at all, shipping, customs, and return disputes. Still, whatever it costs, it would be an interesting and probably worth it to some people.
There is a ton of regulation involved with both intra- and inter-country chemical shipping and purchasing. There are some chemicals that are perfectly legal for normal people to own but not to purchase if you aren't an institution. There are chemicals that require specific handling and packaging, which when shipped internationally become "potential chemical weapons" and thus can carry life prison sentences if not done properly.
We ship both live and dead cell cultures (both extremely pathogenic and relatively benign) that can pose severe risk even when dead. The few times I've had to do international shipments have been a pain in the ass with all the paperwork, special packaging, customs bullshit and then there's the agony of waiting for the shipment to clear US customs, then destination customs, then destination culture screening -- and we have lawyers of who deal with the paperwork for us!
Yes your employer, and maybe competitor like carolina, would be a good supplier in the US but to keep shipping agony to a minimum maybe some place in europe would ship to europeans.
On the other hand amazon can probably ship blank unused new microscope slides anywhere in the world, so maybe they get to ship to .UK
This kind of coordination of which supplier can ship what, where, would be what the proposed startup would do.
What you're thinking of already exists to a great extent -- look at Fischer/Thermo and VWR. They're the Amazon's of science-stuffs (Amazon has AmazonSupply but it is greatly inferior)
Well... sorta but I want to meta it into a generic online purchasing department for any activity.
So as a kit designer, my lab experiment which anyone in the world can buy from the startup for $100 or whatever (of which I get 5% and the startup keeps 5%), needs an arduino, a A/D and D/A shield from some specialty electronics supplier (adafruit?) and a spool of copper wire, clipleads and connectors and stuff from generic supplier (jameco?) and some sticks of different metals like aluminum, copper, steel (onlinemetals.com?) and some rather generic glassware (carolina? VWR? Fischer? or downscale to a ceramic mug or flower pot?) and something like lemon juice in a can or maybe a wide variety of mostly harmless electrolytes like diet coke soda (amazon food department?) Whoops forgot to add a decent printed lab manual (lulu.com?)
Ta da instant lets do introductory electrochemistry at home kit. Send the startup $100 in a single credit card charge, they keep $5, send $5 to me as designer/curator, and $90 goes to about 5 suppliers and boxes start arriving at the end users house.
Now the magical startup wouldn't only do this project or only those suppliers, but it would middleman ... hundreds of kits maybe thousands?
This is basically the drop ship retail model, but for small consumers and small orders instead of the more traditional use of drop shipping a 5 HP air compressor. Also I'd internationalize it, why not. So if you live in some weird country where shipping canned lemon juice is illegal, well, I guess its not available for purchase in that country.
I don't personally want to do this. It sounds like a huge PITA and probably will fail and it'll be hard. Someone else can go right ahead, and I'll probably end up a project curator for a couple projects and most likely a buyer. Unless they try to grab something ridiculous like 50% as middleman, in which case I'd drop them like a hot potato.
When placing any kind of order, you have to look at the seller's reputability and decide for yourself. This project appears to be coming out of a MIT Media Lab project (perhaps this could use confirmation), and the Heritage Chemistry Set is from what seems to be a well-respected shop. It might not be necessary to lump these projects together with other fly-by-night crowdfunding attempts.
The site as a whole is a 'Support Our Project' site which is limited to hardware products, and projects turn into 'Buy It Now' when they are shipping. Projects are vetted to help ensure that the funding threshold is high enough for them to successfully deliver.
In the case of these stickers, the development is already done. Unlike typical crowdfunding campaigns, the creator is not expecting backers to fund development or absorb the risk of unexpected engineering challenges, which is why the funding threshold is set at $1.
Source: I have these on my desk, and they're awesome.
Actually, in the circuit stickers case Bunnie is committed to shipping them (did you see the funding goal was $1 ?) This was more of a marketing move than a raise funds move.
Interesting I thought both the Parallela and the Lockitron were shipping. I see that Lockitron claims they will 'resume shipping' this month and shop.adapteva.com allows orders but is 'out of stock' of the parallela. Such a sad place to be.
Not in time for Christmas but I'll still keep an eye on this one. I think this is great for anyone who wants to get their 4 year old interested in electronics, but isn't comfortable handing them a soldering iron. My girl LOVES stickers.
> At 4, they'll eat the components when you're not looking.
This is highly dependent on the kid. My experience is that some are "eaters" and take a long time to outgrow it while others just never really get into the mode of learning by mouth.
"professional" solderless breadboard, obviously. Aside from 80 bazillion kit oriented "snap together" technologies and wire/spring technologies both present and past.
Also around age 5 I was soldering, there's some obvious "tricks" to it like wear cotton (never synthetic) gloves such that the cotton burns instead of skin, and attach the cord firmly to back of desk (stick a power supply on top of the cord?) such that its physically impossible to reach the lap, etc.
And eye protection when you're snipping off leads if you're doing old fashioned thru-hole. Old timers don't need it because we're good at blinking every time a wire snips, probably because it smarts when you hit your eye which makes it very motivational.
Oh, and wash your hands. Even if using Pb-free, don't be licking that stuff.
I'm worried about the long term stickiness of the LEDs/Timers/ICs. If I was to buy this I'd probably stick foil to the adhesive bottom of the components so they can be rested on top of the copper tape. That or put a few pins on the +/- areas. That way you can tape the copper to cardboard instead of paper and then punch the components through the tape.
I'd worry more about the power carrying capacity of the proposed conductors especially during partial failures. Someone is going to set fire to their clothes one day and it isn't going to be pretty.
Yeah but - these are powered by CR2032s - typical capacity is around 200 milli Amp Hours, and they're usually rated at a maximum continuous current of 1mA with 10mA "pulse" capacity. That's a continuous 0.003W or pulses of 0.03W.
It's probably not _impossible_ to start a fire with a pair of CR2032s, but you're going to have to set it up that way on purpose – the chance of "accidentally" creating enough heat to set non-intensionally-incendiary materials alight is low enough to be ignored.
(Note, I carry a pair of these cells around in my pocket - an LED light attached to my keyring. These cheapo lights rely on the internal resistance in the battery to current limit the LED, with a white LED across a pair of cells, the battery's own resistance is enough to keep the current down under the "let the smoke out" limit of the LED - it might be more than 20mA, but it can't be heaps more.)
They are powered by that here. The inevitable chain will be either the battery will go flat in minutes or there will be brown outs which are inevitable if you have LEDs and non MSP430 grade CPUs hanging off it. The result of this will be inevitably, judging by usual projects I've seen, either stick a PP3 in with a regulator or even worse chuck a cheap LiPoly on it.
My initial concern was that the adhesive might be prone to wearing off after a few reapplications. Their FAQ addressed that point, though not in the way I'd hoped:
"Like normal stickers, they are designed to be stuck exactly once. Since the adhesive takes some time to reach full strength, if you are careful, you can peel the stickers off right away, but this causes the sticker to lose some of its tack (which can make faulty connections in the circuit)."
Certainly, reapplicability would be a design challenge in itself - I can't fault them for eliminating that concern. Still, it would've been fun to see. Maybe a future version?
61 comments
[ 2.6 ms ] story [ 123 ms ] threadWhat happened to that?
Not impressed with flashing LEDs on string.
----
Edit: Add a rant as people seem to miss my point:
Well all the kit companies disappeared as people learned to assemble prefab stuff and purchase ready made consumer electronics made by the lowest bidder.
I'll probably get downvoted for this but...
My real problem is that people want a quick fix now rather than actually learning something or constructing something of complexity. About all you get now is someone plugging an LED into a prefab arduino and crudely hacking together some prefab C functions and it's the next best thing since sliced bread, requires a whole blog about it and much circle-jerking from the maker crowd about how this is the next greatest flashing LED contraption.
Put a 555 or a couple of transistors, capacitors, resistors on the table for a simple astable multivibrator and bricks will be shit. Even the basic maths for working out which resistor has to be used in series with an LED to limit current has to be canned in an iPhone app these days.
This is a cult of people assembling Ikea furniture, no more.
Expensive, poorly designed decade resistance boxes that use pissy little SMT resistors that will catch fire if you have an accident rather than get a little warm: https://www.tindie.com/products/Atlanta_Robotics/decade-resi...
What the fuck? Multimeter anyone? https://www.tindie.com/products/Steves_Hobby_Store/the-stopl...
Flashing crap, most of it no better than $2 chinese plastic junk: https://www.tindie.com/products/category/wearables/
This is precisely what I don't want to see and I wish people would stop worshipping.
A DIY weather station kit that feeds its data to the Raspberry Pi: https://www.tindie.com/products/tmhrtly/airpi-kit/
DIY Amplifiers: https://www.tindie.com/products/diyourfaceoff/fully-assemble...
A DIY 8x8 LED games console: https://www.tindie.com/products/hotchk155/sixtyfourpixels-lo...
DIY musical instruments: https://www.tindie.com/products/hotchk155/le-strum-hack-it-y...
TTL Tennis for Two: https://www.tindie.com/products/wmbuchholz/ttl-tennis-for-tw...
I would rather, for music, use http://www.paia.com/ or http://www.doepfer.de/ for example.
Some of their analogue kits are eye-wateringly expensive for what they are.
Don't see the sort of kits you like being made? Join us! Innovate, and design your own!
Go buy it if you want it.
There's much better stuff out there than when I was a kid and all we had was heathkit. However you need to use the internet, not just the annual heathkit catalog.
Something along the lines of the pie used to have basically one very big slice, which went out of business in '92, and since then the pie has expanded quite a bit, although no individual slice has come close to the size of Heathkit before it sank... the small size is probably why the individual companies are growing instead of shrinking LOL.
As a kit I cut my teeth on building a hero 1 robot from heathkit before I even learned to write cursive. I often tell people that just to up my geek cred. Luckily the drive to do nerdy things has never really left me.
http://www.pyroelectro.com/edu/digital/
If asked, I tend to direct people towards the following books:
http://www.amazon.com/The-Art-Electronics-Student-Manual/dp/...
Note: you need both the student manual (which most people don't know exists) and The Art Of Electronics.
To cover the maths background required, I recommend:
http://www.amazon.com/Mathematics-Birth-Numbers-Jan-Gullberg...
They are not cheap but worth it.
Oh and a calculator. Any old cheap scientific (Casio/TI/HP) will do as long as it doesn't make errors.
The big problem for me was the maths initially. It doesn't take long before you hit a brick wall at the age of 12. My 10 year old daughter is learning algebra and programming (in python!) though at school so things are looking up.
and yes, the resulting S/N ratio is an extremely tough pill to swallow.
In general I detest the kind of attitude you represented in your parent comment, eg people shouldn't doing something they enjoy just because it doesn't meet your standards.
People should still do this, but stop turning it into a cultural movement in which everything unremarkable is remarkable and knowledge is abstracted away into insignificance. The knowledge is infinitely more important than the abstraction as the abstractions come and go.
For an extreme example: When playing around with electricity that knowledge and those fundamentals can and do make the difference between life and death. Some maker contraptions that I've seen that flash lights connected to the mains are so dangerous it's unreal.
I've thought the same thing for the longest while. I love that people of all ages are starting to learn about electronics & firmware. At the same time, the desire to build something sophisticated has people skipping large steps and as a result, build insanely complicated systems that a little knowledge would let them do in a much simpler fashion.
They're learning, but with enormous gaps in knowledge.
But lower down I saw their ideas about using this kit on paper or material, and what not. Which does seem more like craft materials than education, but also educational. So, I'd suggest this kit is a way in. It can get people, kids, interested, and once "hooked" they can then get all bread board about it, then wield a soldering iron in anger.
So, really it depends on how this stuff is used. Any one using this as an education tool would need to sort of spot the talent, and quickly move them on to something a little more educationally useful.
A game of life automaton in the form of a bedquilt would be interesting.
These strange ideas would seem to be a logical extension of the basic product concept.
Kind of like if I want to know what time it is, I'd look at my phone, but if I want to look at something cool on my wall I'd look at:
http://www.transistorclock.com/
I also find Clayton Boyer's clock designs appealing, although my electronics skills exceed my wood butchering skills by many orders of magnitude:
http://www.lisaboyer.com/Claytonsite/Claytonsite1.htm
So its a question of style or taste, as a work of art.
The product seems great. Not sure I see why it couldn't go on its own without the hype machine.
The P112 project did a kickstarter. Mines sitting on the bench, too many other things to work on. A very simple kit given what it does. I'm sad I had to wait like 4 months for someone else to put the SMD components on, I could have done that myself in less than an hour.
The N8VEM people sit on preorders until they get 20 at a time. Sometimes thats a very short amount of time indeed like days, sometimes its a bit longer like years between orders of certain obscure PCBs!
The SpareTimeGizmo people have done some ship off the shelf and some preorder, I think? I was fast on the draw and got one of the last 6120 PDP-8 full kits ever made some time in the 00s.
The KB9YIG SDR people were supply line limited at a very low price, so as they put together sets of bargain price kits they put them up for sale and usually sold out in an hour or at most a couple hours. To say this aggravated people who missed the 45 minute sale window, every time, would be a profound understatement. They switched to a much higher price and off the shelf shipping a couple years ago. I miss paying $11 for a single band fixed freq SDR although its annoying to pay $21 today for the same thing, its nice that its always in stock rather than being something like a lotto.
Why is our funding goal just $1?
Chibitronics is an academic research project. The work to develop this technology will proceed whether or not others would like to participate in our research project. Although the circuit stickers featured in this campaign have been produced in small volumes, they were produced using techniques suitable for mass production -- we are "prototyping in production". If just one person backs this project, we're still perfectly happy to build and ship a single unit, yet we have the process scalability to meet virtually any demand.
It's a bit weird, but I guess they're using it basically to measure demand and size the initial order(s).
Which is kindof the point of hacker news, isn't it?
After my experience with Lockitron, I have no desire to lock away my money for months while fretting over whether or not I'm going to get ripped off.
The same goes for the Heritage Chemistry set which I would buy for any of my kids (but to be honest, mainly for myself), but I just don't have any faith that I will see my $500-700.
So if you define a project called "teach my kid titration" it would understand how to get phenolphthalein and other indicators in Belgium, how to get a beaker in Texas (good luck), etc, and for a modest 10% fee of which they keep half and the designer keeps half, they make one CC charge and magically anywhere in the world boxes start arriving.
This would be tremendously helpful with electronic projects, where I get a custom PCB from somebody, some obscure transistor from somewhere else, and COTS support parts from the "big 3" suppliers.
Something tells me the agony of being a purchasing agent can't be abstracted away for a mere 5% commission. And how to intermediate, if at all, shipping, customs, and return disputes. Still, whatever it costs, it would be an interesting and probably worth it to some people.
We ship both live and dead cell cultures (both extremely pathogenic and relatively benign) that can pose severe risk even when dead. The few times I've had to do international shipments have been a pain in the ass with all the paperwork, special packaging, customs bullshit and then there's the agony of waiting for the shipment to clear US customs, then destination customs, then destination culture screening -- and we have lawyers of who deal with the paperwork for us!
On the other hand amazon can probably ship blank unused new microscope slides anywhere in the world, so maybe they get to ship to .UK
This kind of coordination of which supplier can ship what, where, would be what the proposed startup would do.
So as a kit designer, my lab experiment which anyone in the world can buy from the startup for $100 or whatever (of which I get 5% and the startup keeps 5%), needs an arduino, a A/D and D/A shield from some specialty electronics supplier (adafruit?) and a spool of copper wire, clipleads and connectors and stuff from generic supplier (jameco?) and some sticks of different metals like aluminum, copper, steel (onlinemetals.com?) and some rather generic glassware (carolina? VWR? Fischer? or downscale to a ceramic mug or flower pot?) and something like lemon juice in a can or maybe a wide variety of mostly harmless electrolytes like diet coke soda (amazon food department?) Whoops forgot to add a decent printed lab manual (lulu.com?)
Ta da instant lets do introductory electrochemistry at home kit. Send the startup $100 in a single credit card charge, they keep $5, send $5 to me as designer/curator, and $90 goes to about 5 suppliers and boxes start arriving at the end users house.
Now the magical startup wouldn't only do this project or only those suppliers, but it would middleman ... hundreds of kits maybe thousands?
This is basically the drop ship retail model, but for small consumers and small orders instead of the more traditional use of drop shipping a 5 HP air compressor. Also I'd internationalize it, why not. So if you live in some weird country where shipping canned lemon juice is illegal, well, I guess its not available for purchase in that country.
I don't personally want to do this. It sounds like a huge PITA and probably will fail and it'll be hard. Someone else can go right ahead, and I'll probably end up a project curator for a couple projects and most likely a buyer. Unless they try to grab something ridiculous like 50% as middleman, in which case I'd drop them like a hot potato.
Because it makes no sense to talk of getting ripped off if your intent is to support the idea and help out an inventor.
Kickstarter tries to make this clearer. I see from this project that they couch everything as 'buying' not as 'supporting'.
In the case of these stickers, the development is already done. Unlike typical crowdfunding campaigns, the creator is not expecting backers to fund development or absorb the risk of unexpected engineering challenges, which is why the funding threshold is set at $1.
Source: I have these on my desk, and they're awesome.
8 is a much better age to start electronics.
This is highly dependent on the kid. My experience is that some are "eaters" and take a long time to outgrow it while others just never really get into the mode of learning by mouth.
Also around age 5 I was soldering, there's some obvious "tricks" to it like wear cotton (never synthetic) gloves such that the cotton burns instead of skin, and attach the cord firmly to back of desk (stick a power supply on top of the cord?) such that its physically impossible to reach the lap, etc.
And eye protection when you're snipping off leads if you're doing old fashioned thru-hole. Old timers don't need it because we're good at blinking every time a wire snips, probably because it smarts when you hit your eye which makes it very motivational.
Oh, and wash your hands. Even if using Pb-free, don't be licking that stuff.
I wonder how tough it would be to anondize the copper red...
I'm worried about the long term stickiness of the LEDs/Timers/ICs. If I was to buy this I'd probably stick foil to the adhesive bottom of the components so they can be rested on top of the copper tape. That or put a few pins on the +/- areas. That way you can tape the copper to cardboard instead of paper and then punch the components through the tape.
It's the current, not the voltage.
Video for you: http://www.youtube.com/watch?v=MWuJokR_mI8
It's probably not _impossible_ to start a fire with a pair of CR2032s, but you're going to have to set it up that way on purpose – the chance of "accidentally" creating enough heat to set non-intensionally-incendiary materials alight is low enough to be ignored.
(Note, I carry a pair of these cells around in my pocket - an LED light attached to my keyring. These cheapo lights rely on the internal resistance in the battery to current limit the LED, with a white LED across a pair of cells, the battery's own resistance is enough to keep the current down under the "let the smoke out" limit of the LED - it might be more than 20mA, but it can't be heaps more.)
Then you're in trouble/on fire.
"Like normal stickers, they are designed to be stuck exactly once. Since the adhesive takes some time to reach full strength, if you are careful, you can peel the stickers off right away, but this causes the sticker to lose some of its tack (which can make faulty connections in the circuit)."
Certainly, reapplicability would be a design challenge in itself - I can't fault them for eliminating that concern. Still, it would've been fun to see. Maybe a future version?
The gang over at the graffiti research lab was painting circuits back in '06ish.
http://www.graffitiresearchlab.com/blog/projects/post-circui...