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Royal Mail Pilots 3D Printing Service

richard.cs Re:Unsustainable business model (59 comments)

You can even do small mass production using 3D printers. For a few hundred/thousand pieces, it's likely cheaper to buy 3D printed stuff than to invest in injection molds.

There are moulding processes that are economical from a few tens of units. Mostly these involve making soft moulds from 3D printed forms and the moulds are good for perhaps 50 units each. They are slower though so if you want a hundred units quickly it might be better to print, and just contract out to multiple printing places if you need extra capacity to speed it up.

about two weeks ago

UK To Allow Driverless Cars By January

richard.cs Re:A Progression of Complaints (190 comments)

What do you think happens when you step on the gas pedal? Do you think it's still physically pulling some cable that opens flapper valves, allowing more fuel to flow into a carburetor?

I haven't worked on anything newer than about 10 years old but every fuel-injected petrol engine I've played with has had a mechanical butterfly valve operated by the pedal. The fancy electronics then measures mass flow rate (which is a function of throttle plate position, air temperature, air filter condition, engine rpm, etc) and injects the right amount of fuel. It's not *that* different from a mechanical carburettor except that carburettors measure volumetric flow and have to be tweaked for summer/winter to account for the different air inlet temperature

What about that transmission? Unless you drive manual, you're not actually moving gears around with that lever. You're sending a signal to a computer "Put it in drive" which was also designed by a programmer.

Where I'm from (UK) nearly everyone has a manual transmission :-)

about 5 months ago

How a Solar Storm Two Years Ago Nearly Caused a Catastrophe On Earth

richard.cs Re:FUD filled.... (212 comments)

I doubt natural gas gets from point a to point b by magic.

Natural gas is generally pumped around by turbines burning natural gas, it's cheaper but also happens to be immune to electrical problems. Failure of controls cause valves to stick in their last commanded position though so expect at least some problems with pressure fluctuations, etc.

about 5 months ago

EU Votes For Universal Phone Charger

richard.cs Re:This is what the EU is for (358 comments)

Taking a 240V +/- 6% country and making it a 230V +10%/-6% country whilst not making any changes to the actual supply voltage doesn't sound all that much like a success story. (220V countries became 230V +6%/-10% and all new devices are designed for 230V +/-10%)

about 9 months ago

I wish my cell phone was...

richard.cs Re:Big batteries at any cost (495 comments)

This. I wouldn't go as far as Sowelu but an extra few mm of thickness (say up to a max of 15mm) for a greatly increased battery life would finally convince me to get a smartphone.

1 year,22 days

Solid Concepts Manufactures First 3D-Printed Metal Pistol

richard.cs Re:New possibilities (333 comments)

Even if the machine itself could handle it (i.e., had multiple material-handling streams), you would have a tough time getting the dissimilar metals to properly fuse

I find the idea of changing materials part-way through a piece interesting, you might not be able to fuse them but I'm imagining something similar to a dovetail joint, printed in place and utterly permanent. Essentially just mechanically interlocking the different materials during printing.

about a year ago

Linking Mass Extinctions To the Sun's Journey In the Milky Way

richard.cs Re:spiral arms? (199 comments)

Do the spiral arms move w/respect to all the stars like some sorta density wave?

That's exactly what the spiral arms are, they can't be the same stars orbiting together in that shape as that would imply a rigid body rotation. The situation where everything moves around together as if it were nailed to a rigid cosmic disc doesn't work because the orbit time of the stars at the centre of the galaxy is less than that of the stars at the edge. This is a consequence of the orbital physics, it's essentially the only way the forces can balance.

So, the stars in the centre whiz around quickly (in cosmological time anyway) whilst the ones at the edge take forever. The spirals are simply areas of higher star density but they are not the same stars all the time. This region does rotate but more slowly than the stars contained within it. So, why are there areas of increased star density? No-one's entirely sure but it seems likely that these are actually regions with higher rates of star formation, with many young, short-lived blue stars.

about a year ago

It Takes 2.99 Gigajoules To Vaporize a Human Body

richard.cs Re:Disintegration (272 comments)

80kg of water is about 136m^3 (4,800 cubic feet) of steam, so you'd better make sure there's a window open cos that's the volume of a cube with sides of nearly 17ft.

80kg of water is about 0.8m^3

80 kg of water is 0.08 m^3 (1 litre of water being a cube 0.1 meters each side and of mass 1kg), if you turn it into steam it expands by about 1700 so assuming atmospheric pressure gives 0.08*1700= 136 m^3 of steam as the OP stated.

about a year ago

GPS Spoofing With $3000 Worth of Equipment and a Laptop

richard.cs Re:It's news worthy but isn't at the same time ... (180 comments)

This is well known to be possible, has been done for years, and you can buy commercial test equipment that sends spoof GPS signals (for testing GPS receivers obviously). More importantly there's another simpler way that cannot be dealt with by signing - just relay GPS signals from elsewhere.

If you capture GPS data at a point in space and retransmit the whole lot with enough power that the receiver sees only your signals then the receiver sees all the same phase relationships that put it in the location where you captured the data. It has no way of knowing it's been delayed by a few microseconds and signed GPS signals would look perfect. The only way around that is to compare it with inertial navigation, loran, etc or perhaps to have a very accurate clock on board to try and spot the extra delay.

about a year ago

Hackers Reveal Nasty New Car Attacks

richard.cs Re:This is why my car is airgapped (390 comments)

Like you I'll not worry about it until I get a car with some silicon in it. It does have two germanium transistors in the tachometer though, maybe I should be worried :-P

about a year ago

British Prime Minister Promises Default On Porn Blocking

richard.cs Re:porn (311 comments)

Why be ashamed of it?

about a year ago

British Prime Minister Promises Default On Porn Blocking

richard.cs Re:Incomplete summary (311 comments)

This. After going off on a tangent about the unrelated (and already blocked and illegal) issue of child porn, which he deliberately conflates with porn in general, he then throws this in. I have no idea what it's supposed to mean.

about a year ago

British Prime Minister Promises Default On Porn Blocking

richard.cs Re:Fun times if you don't control your net account (311 comments)

Ignore the comments about moving out - I know how hard it is at the moment. But seriously, just tell your mum you want to watch porn, you're 26 and there's nothing wrong with it. Thinking all porn is illegal probably makes her a Daily Fail reader right?

about a year ago

Interactive Nukemap Now In 3D

richard.cs Re:Nope, can't make a gun-type with Pu (192 comments)

You can make a gun-type bomb with impure plutonium, what you can't do is make one short enough to deliver in a missile or a plane. Built diagonally on the 100th floor of an office building or more feasibly at ground level in a dockside warehouse however....

You "just" need to increase the assembly velocity, and there are ways of doing that which are simpler than building an implosion device. And as you point out a fizzle is still a significant yield, and much dirtier.

Give a final year physics student a mechanical workshop and the plutonium, all they'd need is the funding.

about a year ago

Comcast To Expand Public WiFi Using Home Internet Connections

richard.cs BT also does this (203 comments)

In the UK BT does this. Their customers can use any of the hotspots for free and everyone else has to pay, no free hour.

about a year and a half ago

White House: Use Metric If You Want, We Don't Care

richard.cs Re:Sure beats jail time... (1145 comments)

when their bottle supplier decides to call it a day

Unlikely to change for that reason. Cheap beers might come in standard bottles but premium beers tend to have custom bottles anyway with brand names and logos in the glass. As long as they see a benefit in branded bottles they can have them made any size they like at no change in the cost.

Canned beer is virtually all in 330ml quantities

I assume you're Australian then? In the UK canned beer is 440 ml or 500 ml. Only soft drinks tend to come in 330 ml cans. 250 ml bottles are very rare here but 330 ml is common for many imported beers.

about a year and a half ago

The Power of a Hot Body

richard.cs Re:Matrix (161 comments)

Posting to undo dodgy mod.

about 2 years ago

Hacker Behind Leaked Nude Celebrity Photos Gets 10 Years

richard.cs Re:Really? (346 comments)

Replying to void incorrect mod.

about 2 years ago

On Nov. 22, 2012, I expect to be ...

richard.cs Re:Working to cover for the USA (340 comments)

Can someone please explain what this distinction is that Americans are making between holidays and vacation days? It's not something that's familiar to me.

I get 5 (usually) bank holidays in a year, i.e. public holidays when the vast majority of people are off work, 25 days paid holiday and I can build up 8 days worth of flexi leave in a year. By default I can only carry 5 days over and use them within 2 months but in practise if there's a good justification, like that it benefits the project, then I can carry over whatever I like.

more than 2 years ago


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