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Comment Re:I think the answer is obvious (Score 1) 174

3D printing is still fiddly, complex, error-prone, expensive and slow.

This. We could stop here but let's not, I have more to say as well.

FDM style printers (the cheapest kind) require wrapping your head around calibration, nozzle diameters, temperatures, slices, alignments, supports, bed heating, the properties of PLA / ABS and all the rest. If you're lucky you'll set the printer going and hours later your efforts will yield some crudely finished single colour part. If you're unlucky you'll come back to discover something that has skewed left, warped on its base, or turned into some dante-esque spider's web that has stuck to everything.

#1 thing that should have been done/should be done to improve 3d printer uptake is working automatic bed leveling. AFAICT (and I am about to test this theory) the best way to accomplish this is with an inductive sensor designed for iron, detecting an aluminum print bed. Aluminum is pretty much the best base anyway, since glass can break all to crap while you are removing your print job. Inductive sensors literally cost five bucks and the hardware needed to interface one which isn't already present on e.g. RAMPS literally amounts to a grand total of one voltage divider, aka two resistors. IIRC 10k and 15k are typical, but whatever it takes to get the output signal down to 5v. It doesn't even matter whether you get one which is NO or NC because the software (Marlin, in my case) can detect either type of signal with correct configuration.

The #2 thing that should have been done is more centralized sharing of print temperature settings for materials. After bed leveling, just finding working print settings is the biggest PITA. If you're not buying from someone who gives you some starting values to work with, then you have to go on a web safari quest to figure out where to start.

Way down the list, probably, is eliminating all these stupid microswitches. Hall sensors are more reliable and cost little more. Even if you have to get them on eBay, whole PCBs with a sensor mounted on them are only about twice as expensive as microswitches worth buying.

As for the single-material print job issue, this is the printer I've got, it's reasonably priced and its great sin seems to be a crap auto-leveler. I've got an inductive one in the mail. Deltas take most of the fiddly-ness out of the system at the cost of potentially dropping a hot extruder on your print job if you don't program them correctly. Which all comes back to your point... they should be set up better for the user. I am willing to do all this fooling around to get the thing working but the average user just wants to print and have something come out.

I actually don't think having a crappy-looking single-color print job come out is what keeps most people uninterested in 3d printing at all, though. I think it's really all about the PITA factor. If you offered people a machine which was both cheap and easy to use, they'd jump all over it even if it only had typical resolution and speed and was limited to a couple of materials.

Submission + - How to View the SpaceX Falcon 9 Return to Flight at Vandenberg Air Force Base (perens.com)

Bruce Perens writes: Silicon Valley folks should, sometime, take the opportunity to view a launch at Vandenberg Air Force Base. Lompoc is 4-5 hours from the Bay, 2.5 hours from LA if there's ever no traffic. An upcoming SpaceX launch is notable because it's their return to flight, months after their last attempt blew up on the pad during a pre-launch test. Read how to view the launch.

Comment Re:logging (Score 1) 226

what did they replace SystemD with and how does it log?

Unless they tell you so, you should assume they did something sensible like use something syslogd compatible, and if you don't like it, you can switch to another one. From googling I get the idea it's rsyslog.

Comment Re:Init alternatives (Score 1) 226

The truth is that the boot speed improvements of systemd are effectively notional. The boot process is so fast now that starting in parallel only saves you time when something goes wrong. If you regularly have a problem during boot, then you should think about fixing that regardless of what your init system is.

Comment Re:I thought diesel ran cleaner (Score 1) 219

Expanding isn't "reacting to heat".

What? What do you call it, then? I didn't say it was reacting with heat. Although it does react with oxygen in the presence of heat, to form NOx, that's explicitly not what I was talking about.

But, back to the original point: Diesel engines take in much more atmospheric air than gasoline engines when running at normal loads (highway cruising).

Yes. But they consume no more when wide open. The size of the exhaust is defined primarily by the maximum flow, not the cruising flow. (That defines other design characteristics more.) Diesels tend to have higher peak boost in spite of their typically higher static compression ratios, but they also tend to have significantly lower RPM limits and tend to run less RPMs while cruising.

Of course, all of this has been muddied by the introduction of the direct-injected gasoline engine, and by developments in diesel engine technology. Not only do GDI motors have higher cylinder pressures and thus higher temperatures, but there are also now diesels with [automated] throttles. As well, the recent crop of automatic transmissions with many gear ratios (8 now being common, 9 not being uncommon, and 10 beginning to roll out) and multiple overdrive ratios has led to gasoline engines being used at much lower RPMs...

Comment Re:How the fuck.... (Score 1) 219

Yeah maybe in America. But that is a fantasy land in terms of fuel. This article however is talking about other places in the world.
In Australia for example most heavy busses have switched to running nat gas because it was cheaper. Most taxis and many passenger cars did too though these are being displaced by electric.

all of which makes sense, but what about long-haul trucking? the hauls are really long in oz.

Comment Re:Think outside the container... (Score 1) 219

I can't help but be a little amused at all the people saying cities could never ban Diesel because there's no acceptable alternative.
There is, of course, just not for long-haul trucking.

You could probably switch to turbine-electric and burn... well, whatever you wanted really, but the only thing which would have the same kind of energy density is jet fuel. That would only cost what, an order of magnitude more or something? But the good news, everyone, is that we're all going to be getting higher-grade fuels whether we like it or not. It's not going to be possible to get much better emissions out of internal combustion vehicles without them. The automakers want to see even higher-grade diesel fuel, and higher-octane gasoline.

Of course, if the Trump takes a Dump on CAFE somehow then we might well not get any of this stuff any time soon...

Comment Re:Stupid (Score 1) 219

Natural Gas for trucks.
Electric, Natrual Gas, or Petrol for cars.

Natural gas? So, you're pro-fracking. Cars are more important than clean water. Nothing is good about petrol, either.

Even if it weren't ecologically retarded, natgas is not a viable replacement for diesel. We use diesel for long-haul OTR trucking for many reasons, but not least because of range. You have to make many more refueling stops for gasoline than for diesel, and you have to make even more for natgas.

Now, to be fair, it is possible to make natural gas from an ecologically friendly source — feedlot manure. Currently this is mostly put into holding ponds to sit and stink for a time before being flushed into a waterway. The smart thing to do with it is put it into tanks (or even into glorified ziploc bags such as the ones often used as water tanks now) and let it cook itself, producing methane in the process; it's going to do this anyway, but we can capture it and put it directly into any vehicle with a propane conversion which involves an O2 sensor. You can buy the conversion parts (the PCM, injectors, and fuel rail) straight outta China for around five hundred bucks.

Methane aside, there is also Butanol, a 1:1 replacement for gasoline. BP and DuPont own a company called Butamax which holds the patents for cost-effective commercial production, which were developed partly with our money. GE Energy Ventures owns a company called Gevo which would like to sell it to us, but Butamax sued them to stop production.

As for diesel, the best replacement is "green diesel", which is what you call it when you crack fats (waste or otherwise) in a distillation column such as we currently use for the distillation of crude petroleum. Like biodiesel produced by the transesterification of fats with methanol or ethanol it is a carbon-neutral fuel (assuming you get your conversion heat energy from a carbon-neutral source) but its other properties are more similar to petroleum diesel, like its gel point. It can be blended with 2-10% traditional biodiesel to deliver a fuel which can be used in any diesel engine and, which will actually extend the life of its fuel system with superior lubricity.

The best solution for reducing emissions in locations where it is excessive, assuming we're going to keep driving around like a horde of motorized lemmings, is battery electric. So sad, it only solves the needs of what, is it 80% of the population? Even if were only 50%, that would still be a massive victory.

Comment Re:So much for biodiesel use... (Score 1) 219

Diesel engines used to run without making ANY NOx. However, because of the political need to reduce CO2, they were modified to minimise CO2 regardless of the consequences for NOx.
Totally separately, if you don't have a particulate filter, the particulates are pretty bad.

Well, congratulations, you got that completely and totally wrong. You could not be more wrong if you were trying to be wrong.

First, NOx is produced any time you have combustion in the presence of nitrogen. Diesels produce more NOx than gassers because they have higher combustion temperatures. It's not unusual for someone to turn the fuel up on their diesel just a bit without understanding the consequences and melt a hole right in one of their fancy forged Aluminum pistons. This is why an exhaust gas pyrometer is a mandatory upgrade (if not fitted from the factory) for anyone who wants to increase power in their diesel. You can cook things very easily, mostly pistons and exhaust valves but also turbochargers.

Second, gasoline engines produce just as much soot as diesels. They produce finer soot, which is more dangerous. The class of soot which gasoline engines produce is collectively termed "PM2.5" or particles of 2.5 microns and smaller. This is the smallest common classification of soot particles, and it is by far the most dangerous because these particles are so small that your cilia cannot sweep them out of your lungs. They can only be removed by adhering to sputum which is then expelled by coughing. Diesel catalysts re-burn diesel soot, which is nice big chunky particles of 10 microns or larger, until it too is PM2.5. This makes them look a lot cleaner, but it actually makes them much more hazardous to health.

Diesels with clever injection systems but without catalysts are the most health-friendly internal combustion engines available which run on liquid fuels. The only internal combustion engines which are superior in that regard are propane engines (typically gasoline conversions, and not purpose-built) run on bio-methane, and lubricated with bio-based oil.

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