"it needed to be sufficiently innocuous for in-flight use"
Good luck with that !
If you open it up, the insides look enough like a home made bomb to scare the crap out of any TSA agent...
It's a tip of the hat today to Michael Castor, who caught our eye with his attractive fusion of plywood, carbon fibre and Raspberry Pi, dubbed the "PiPad". Top view of the PiPad Michael's plan was to build an "all-in-one system that was usable, portable, and Linux-based", but which also "had to look good". Furthermore, it …
The highly skilled and extremely motivated folks at the TSA are all fully aware that *any* bomb has curly wires leading to the explosives and a red LED count-down display.
Along with, as we were informed by Sherlock, the all important off switch (which seemed to be a vital could not be omitted part of a bomb that is detonated by remote control but which curiously still had a 2 minute red LED countdown before exploding)
yeh I just watched that last night...
it's 'how stupid people think clever people think' tv isn't it.
the remote detonation thought no mobile signal... the LED countdown, the off switch...
you sort of wonder how the folk writing the script for this kind of stuff have grown to adult size, without natural selection mowing them down crossing a road, sticking their fingers in a power socket or falling off a cliff ('oh...THATs what gravity does).
I seen to remember the last series not being quite as fuckwitted, but I might just be a year more grumpy.
> the all important off switch
I'd want an off-switch too. You don't know how far you can throw it when you touch two wires you shouldn't during construction. It should be taken out (or disabled) at deploy-time though, or direct-connected to the detonator. "Ah, there's the Off swi..[BOOM!!].
> bomb that is detonated by remote control but which curiously still had a 2 minute red LED countdown
A timer backup in case a dead receiver battery/signal blocker etc kills the remote trigger is a sensible design choice IMO. An LED display is a bit showy though.
I've taken some unusual stuff through security quite often - custom pc boards for interfacing with servo drives, servo amplifiers, etc; things I don't trust to check through - and the worst that's happened is I've been asked to explain what it is. By the time I get to 'PID loop' they're usually convinced.
The only time I've had a bag searched is when I carried a wrapped-up bundle of hinges, which as far as I'm concerned is precisely the kind of thing that they ought to take a look at if they're going to look at anything. The only evidence of it was a note saying they'd looked; they were wrapped back up and nothing was out of place.
I know that it's customary to only put horror stories on the internet, to ensure that everyone things the world is as terrible as possible, but unfortunately I haven't got one despite having spent a year flying all over the world with strange electronics in my carry-on. Oh well!
You got lucky. On my last trip, the TSA took an interest in my first aid kit and emptied then scattered the contents through my checked bag. They did leave a note. I guess they wanted me to know that it was them and not just a baggage handler looking for stuff to sell on eBay.
"Nah. The highly skilled and extremely motivated folks at the TSA are all fully aware that *any* bomb has curly wires leading to the explosives and a red LED count-down display."
I think you've just given me an idea for my next screen saver.
Naturally all it does when it hits zero is to re cycle back to whatever it was set to.
Much maligned for being cheap and nasty however it is extremely strong, usually does not warp or crack and is an excellent choice for what he did especially as he had some lying around, that's often the best choice.
If he does make one from an exotic wood I hope he uses a more efficient method to cut the frame, that router wasted more wood than was left.
Yup, it's a great material. One of my bass guitars is made of plywood (it's a Japanese clone of a Rickenbacker 4001) and the only way you'd know without disassembling it is if you look inside the bridge pickup cavity. As you say, it doesn't warp since it's made from layers of thin veneer, whereas solid wood can warp and crack as it dries out with age. This is particularly true nowadays, as well seasoned wood is very expensive - hence the use of MDF or soft woods like pine.
A friend who builds rollcages for competition cars recently had to contact the MSA to check how to proceed when installing a rollover hoop to a vintage car with 19mm ply floor - standard MSA regs call for welding the cage to the floor. The MSA confirmed that all you have to do is bolt the plates in rather than weld them; the wooden floor is actually stiffer & more resilient than the pressed steel in moderns.
I will continue to malign cheapo Chinese plywood.
Here in Canada our mighty leaders have determined that the best way to grow our economy is to ship raw logs to China, then ship the finished plywood back for use here.
It IS cheap, but as if often the case with Chinese products, you get what you pay for.
When we painted the stuff the top veneer BUBBLED.
Well done for having done it, but there are far more interesting things going on in the maker, hacking and repurposing communities for those willing to seek them out. This doesn't even have the appeal of being cheap to do.
Perhaps that's the real message - that it doesn't matter how low-cost the motherboard is (be that a Raspberry Pi or anything else), it's the cost of everything else which is the main obstacle to turning that into something useful and usable.
Sir, you are a Sandbender. I know of no higher praise.
"It started with a woman who was an interface designer ... Her husband was a jeweller, and he'd died of that nerve-attenuation thing, before they saw how to fix it. But he'd been a big green, too, and he hated the way consumer electronics were made, a couple of little chips and boards inside these plastic shells. The shells were just point-of-purchase eye-candy, he said, made to wind up in the landfill if nobody recycled it, and usually nobody did. So, before he got sick, he used to tear up her hardware, the designer's, and put the real parts into cases he'd make in his shop. Say he'd make a solid bronze case for a minidisk unit, ebony inlays, carve the control surfaces out of fossil ivory, turquoise, rock crystal. It weighed more, sure, but it turned out a lot of people liked that, like they had their music or their memory, whatever, in something that felt like it was there. . . . And people liked touching all that stuff: metal, a smooth stone. . . . And once you had the case, when the manufacturer brought out a new model, well, if the electronics were any better, you just pulled the old ones out and put the new ones in your case. So you still had the same object, just with better functions."
Gibson. Idoru. GIYF.
There are lots of shops with CNC routers that will make you the parts you want. Unless you plan to open a business, it's probably cheaper than buying one. I looked at building my own CNC router once. It was cheaper to buy a used commercially made one on eBay and even cheaper to send CAD drawings to shop and have them ship back the parts in a day or so. Going DIY is fun, but not always the cheapest alternative. If you still want to build your own, look for a parts kit of the major mechanical bits or find a deal on a used/not-working one that will yield most of the more expensive kit.
Russian birch ply is marvelous stuff. You can cut yourself on the edges if you are not careful. They make junk ply too, but that doesn't usually get exported since worse can be had for even less from South American and Indonesia. Finland birch ply is the absolute top. The sheet with outdoor rated phenolic adhesive is incredible. Apple ply is a compromise for larger projects where cash is tight. Typically, the more individual plies, the better and you also want it to be void free.
The carbon fibre is cool, but remember that it's electrically conductive. Mounting a PCB with the connections contacting the CF might short out. It's not a dead short, so sometimes it could just lead to unexpected weirdness. Shorting battery connections could lead to a fire.
A speaker manufacturer built some 18" woofers carbon fibre cones for PA systems and began getting them back with fire damage. The leads to the coil contact the cone and with a high power amplifier, there was enough current flowing through the CF between the leads to start a fire. Oops.