3961 posts • joined 8 Oct 2009
Around for decades already
And it's called the IBM Model M.
Fracking hell, fracking dunkel, fracking weizen, fracking Kölsch: it'sall fracked if this goes ahead
Not a hivemind
The "You can't 3D-print a gun" was written by Lewis Page, someone who's been dealing with things that go boom for quite a few years, and is able to tell about it. This one's written by Simon Sharwood, right at the other end of the globe, and essentially relates to a test by the Aus police force and their publicity. Which, from this admittedly small sample has shown that the chances of such a gun not working as intended is one in two, which not at all contradicts Lewis' assertions.
Re: A Controvertial Topic (for a change)
has less to fear from
the revolting exploding peasants
There, fixed that for you (where's the duct_tape_and_zipties icon?)
"something palatable out of a printer"
Sucking on their towels' corners getting a bit old?
Re: Intergalactic give way
In certain places here on Earth it's the loudest horn which has right of way, but in the vacuum of space that's not much of an option.
A long time ago in
a galaxytwo galaxies far, far, away.
Re: Duck and cover
Jamie Hyneman built a remote-controlled vending machine for a $soda_manufacturers' ad campaign. Should be a good starting point.
Well, they'd have to stand right next to you, as the idea is to have the drone hover just a few feet above the net, then, once it'd had ascertained it was the right pole, drop the can.
But if there was an 11-foot Pole standing next to me, trying to get my beer, I think I would simply let him.
An insect net on a ten-foot pole (what else?) which has an RFID-like tag fitted. The drone then should have a camera and tag reader (one that can read the tags from about a meter away) fitted, allowing it to release the can into the right recipient's net. Also, because of the net and the drone's proximity to it, it can just drop the can and be done, no need for a parachute (I take it they don't want to fly right at the recipient for fear of people grabbing the drone).
Total lack of comprehension. Again.
This is not about the manufacturing process. This is about US export laws regarding weapons.
Kindly bugger off to reddit or something.
Missing the point
Which is that it can rapidly (FSVO) make one-off parts (or a small series of), obviously with certain limitations regarding shape and size, including, but not limited to, parts needed to build a 3D printer.
If you think that means they can make all the parts needed to build one, there's a bridge I'd like to sell you.
Re: "acquiring a massive spin from the rifling"
Well, it's more than your car, for example.
My car (insofar as it can be called _my_ car) doesn't spin, and I bet yours doesn't either. Certain parts of it do, at best.
What part of a gun can you make with a 3D printer and not a CNC Milling Machine?
I'd think the grip would be easier to do on a printer, but even easier would be to take a lump of Polymorph and shape it.
Re: On course for UK - Oz in 30 minutes
Mewton-meters is the force with which a cat compels you over a distance to open the door for it, or feed it.
Re: On course for UK - Oz in 30 minutes
Force is measured in Newtons (N). Mewton-meters is momentum.
Re: Nice looking hardware
It is the fuggliest thing I have seen in a long time.....
And this matters, exactly how?
(It's also evident that you havent recently seen a Fiat Multibarf)
Re: @the J to the C
Nope, you said that 300 quid wouldn't get you a 3D printer. No statement modifiers to the effect that that 3D printer would have to be able to print a gun that would be comparable to a milled one. And the gun under discussion here CAN be printed on that £300 printer, no ifs and buts.
Re: Not a danger to society, but a danger to the user.
From the article: " there's going to be nothing in the design that makes the metal addition crucial, ". Evidently, it's not the chamber.
The gun is made from ABS, a stupendously tough plastic; they make lifeboats out of it. Also, it's got an extremely short barrel; the bullet will be out of it, allowing the gases to escape, before the chamber has time to deform appreciably (which is what happens before it ruptures). Apparently that's what makes using a plastic chamber feasible.
This was about the third world, and why they weren't producing cheap weapons themselves. If you had bothered to read the comment this was a reply to, you might have gotten that bit.
And also, if you had used the 'reply' button next to the post you're replying to (which you are, evidenced by the quote), your reply would end up where it's pertinent.
Re: Oh puhleeze.
that's why we need to protect them so they survive that stage :). This is not helping.
Still, people clearly enjoy making, or trying to make, new ones (kids, that is), so I don't quite understand the reasons to keep kid loss at a minimum.
@the J to the C
you could have a CNC up and running for less than £300, try getting a 3D printer fot that cost
Fail yourself. My 3D-printer, a Mendel90, has ended up costing roughly £350, and there were several ways I could have shaved those 50 quid from the bill, like scavenging printers and scanners for materials, something I simply couldn't be bothered to do.
Re: If someone breaks into my system via a remote console connection,....
Then either you're using the wrong kit, or you're a drooling moron who can't read manuals.
Re: Ah... Serial ports
You can't put useful security on the serial port itself, there isn't the CPU (or the bandwidth) in most devices.
Bollocks. The common problem is not that it can't be done (show me a reasonably current embedded system that has less processing power than a MicroVax II, and even then it's not a problem), but that it simply isn't done properly, if at all: fixed usernames and passwords are all too common.
I have two; one's a 233MHz, the other is 166MHz (I think). Equipped with an 8GB SSD and maxed-out memory the 233 one was the perfect companion for my GF's two-week trip to New Zealand some years ago: robust, compact (way smaller than even a Thinkpad X) and not very attractive.
I doubt you ever used a 5MX for real work. That is, stick it in your pocket with the serial cable, climb up the stairs and ladders into the bowels of a production plant, and use it to reconfigure the sodding bit of misbehaving networking hardware with its amnesiac firmware.
Re: Gravity detector
If your gravity detector is (close to) horizontal, vector math shows that there's some fierce accelerating going on, and as a result of that there's a pulling force on the spring + cord, significantly larger than the pull by gravity. If the acceleration stops, the weight will drop into a vertical position with respect to the rig again; it will not 'overtake' the rig (except for a short moment when it will not yet have started to fall, and the force of the spring will start to reel it in). Only if the turbulence is such that the rig gets actively stopped and/or pushed downwards there's a possibility that the weight can slam into the rig. But I think those are conditions you wouldn't want to launch under.
OK, but then, if it didn't have any (or just a few short) runs, the whole kaboodle would be falling for those 30 seconds before firing. That's quite a distance (2..4.5km, at 20..30 secs runtime) and it will have picked up an impressive speed too (200..300m/s, not counting drag and the deployment of the parachute). I don't think that would be a suitable condition to have LOHAN in at the moment supreme.
Just a clockwork from a toy
Curious. What kind of toy would that be, with a resettable clockwork that runs for 5..10 seconds (enough to not time out on turbulence) and robust enough to do the job?
Re: badge reel
You could put your badger eel inside the launch rig, where it's warm and cosy. Run the cord up to the swivel joint and adjust everything so that when the two lines of the inverted 'V' are taut, the cord of the badger eel is just a wee bit off from maximum extension, so that it won't ever need to take the weight of the rig. Then of course the conducting disc, and a bunch of contact pairs around where the badger eel cord passes through the lauch rig fuselage.
Re: Parachute cord and springs?
c) Weight falls free from cage and pulls figure 8 loop from between plunger and stop plate
c.1) because balloon lift is lost the plunger and stop plate will start falling just as fast as the weight which is supposed to pull the cord from between them.
What I'd like to see
is an indication of how much of a problem turbulence actually is under average launch conditions, at what heights it tends to occur, and whether it actually causes sufficient loss of pull to cause a false trigger when using a tension switch on the balloon tether. There's a video of some Lego craft getting up into the stratosphere, and not being shaken to pieces in the process. Or did they glue the thing together?
Because when turbulence stops being much of a problem over, say, 5000m, then you could hook a pressure switch set to the equivalent of 7500m into the circuit (parallel to the tension switch if the pressure switch opens at altitude, in series of it closes).
Re: Don't over think it
That's not in any way different from having a switch inside the rig, activated by loss of pull from the balloon cord. And it's just as sensitive to false triggering from buffeting.
Re: Second balloon
There are ways to rig the second balloon so that it only starts to provide pull on its tether after the main balloon has burst, but they involve pulleys (undesirable with regards to icing) or levers (extra weight), and you need to ensure the balloons don't chafe against each other or the rigging.
Yes, I don't know how far up it gets cold enough for water to freeze
You've just disqualified yourself there. It certainly freezes, and already well below the intended maximum altitude. Your proposed solution would trigger, as a rough estimate, at 15% of that intended maximum altitude, and be utterly unusable as a failsafe trigger after the balloon has burst.
Re: Needs to be simple ...
You could rig a switch plus a tether that pulls the switch if LOHAN slides off the rod, but that would require LOHAN's batteries to be able to supply the juice for firing the igniter.
And I think the idea is to get LOHAN to fire in an upwards attitude if at all possible. Firing the motor when going down would be necessary only if there's concern about having the craft landing with an unused motor.
Re: badge reel
OK, now test this at minus 40 after being subjected to moisture at lower altitudes.
Re: Accidental firing in turbulence
This will keep constant force on the switch
It does not. As soon as the distance between balloon and rig decreases, the tension on the shock cord decreases too. Which means you may still have some tension where a normal cord would have gone slack, but constant it is not. And it may induce oscillations in the line, so it may not even keep any tension at all.
Attach a suitable switch (of the pull-teflon-strip-from-between-contacts type) at one of the parachute's attachment points, and attach a cord at the opposite attachment point. Make its length so that it triggers the switch with the parachute roughly half to three-quarters open.
Less chance of binding/freezing than with the cord-through-rings-on-parachute setup; may require some experimenting to find the right switch and get the setup right; it also requires wires running down from the parachute to the launch rig.
Now go back to the Tower of Pisa and Galileo's experiment there: would your weight fall faster than the switch it's supposed to trigger?
Re: Any way the whole rig can be kept stable in free-fall?
Stabilising fins need air, and they need it flowing over them to function. Both conditions are sorely lacking at 30+ km high.
That would involve electronics again, or a mechanical clockwork (likely to freeze or be otherwise impaired by the cold) that is resettable.
Sorry, you can't attach anything to the balloon, except at its neck.
Solving the wrong problem
Yeah, some of your suggestions will burn. The question, however, is getting the igniter (which is already present, and has been demonstrated to work well) to ignite at the right moment. And if you're not sure of the ambient temps, you may want to consider that there's snow all year round on the Matterhorn. This rig is going to reach altitudes at least six times as high.
And go read Ignition! for enlightenment regarding getting self-igniting stuff to burn when you want it, and not before.
Re: slack bits
Roughly what I was thinking, but instead of the (balloon) lift line holding a switch open against a spring, let the parachute line (slack during ascent, taut once it deploys) pull a teflon strip from between a pair of NC contacts.
Re: Page 2 - top-most picture
"Danger of deep depression and apathy due to nog being ever able to fully grok what is happening here"
Compact Muon Solenoid
That's a definition of 'compact' which I wasn't aware of until now.
Some pan-dimensional equivalent of Mythbusters at work, then.
Yes but that's no different from anyone driving a lorry or sitting on the top deck of a bus.
That's the same argument that has been used to defend Google's WiFi slurping: "anyone can do it." Could be, but not on the scale that Google does. By far. And there's the correlated data that Google tacks onto their pics and their collected SSIDs. Do you expect someone taking a snap from the top of a bus to put the exact address in the comments when uploading the pic to Flickr? And even with GPS tagging, you first have to go from your target addres to GPS data, then find any pics that match those tags and see if they're what you're after. Google hands it to you on a plate.