It can take an 80% receiver to finshed in about an hour.
Can it machine a finished receiver from a block of aluminum, even if it takes a few days?
It can take an 80% receiver to finshed in about an hour.
Can it machine a finished receiver from a block of aluminum, even if it takes a few days?
First, guns don't protect, never have, never will.
The first eight of your 457 word wall of text shows you're so out of touch with reality that there's no point in reading the rest.
The primary function of guns in private hands is to protect those who carry them. They do that exceptionally well. In criminal attacks, resistance with gun is the most effective way to avoid injury or death. It's substantially more effective than the second best - knuckling under completely - and beats the pants off everything else, from running away, to trying to talk your way out, to resisting with bare hands or other tools. (Resisting with knife is about the worst.)
Research on self-defense is hard, because faiures leave tracks in crime stats while successes usually don't (and often leave the self-defended victim with an incentive to keep quiet about it). Nevertheless, even the first well-run projects were able to put a lower bound of guns preventing or aborting more than six times as many crimes as they aid in committing.
In private hands they're safer than police, too. A defense-with-gun is usually effected by no more than brandishing or occasionally getting off a round in the general direction of the perp. But of those instances where a victim or a policeman shoots someone believed to be a perpetrator, the cop is over 5 1/2 times as likely to erroneously shoot an innocent than an armed private citizen.
My family has substantial personal experience with armed self defense. For just a few examples on my wife's side: In college she was accosted by the rapist in the window, who was dressed in just running shoes and a dirty knife. Fortunately there was a hunting rifle behind the bed: She actually had to go as far as cocking it before he stopped trying to get her to drop it and jumped back out the window - apparently to take it out on another girl a few blocks away, with over 130 cuts while raping her. Her mother defended self and family against a Klan attack with a pistol. (Her granddad was caught away from his gun, though, and had to do his anti-Klan defense with a hammer.) Then there was the aunt, the uncle,
At the larger scale it's hard to argue with the fact that the US, founded in a revolution (by religious nut with guns) against their self-admitted "legitimate government" and with over half the adult civilian population armed, has now gone over two centuries without a substantial attack from abroad and only one major internal war, while Europe continues to suffer from genocidal wars, often with multi-million body counts. (With the exception of Switzerland, of course: Every adult citizen there is armed and has had military training. Even World Wars go around them.)
It's also hard to argue with the fact that the US is multi-ethnic, and the common denominator of each of its ethnic groups is that their members' murder victimization rate is substantially less than that of contemporary members of the same ethnic group still residing in their land of origin.
As for resisting an oppressive regime if push comes to shove: We have experiences like "The Battle of Athens" just after WWII, and the documented question from Nixon to a thnk-tank about what would happen if he suspended the presidential election. (Answer: That would precipitate an armed rebellion, and the population was well enough armed that it would succeed.) Uprisings aren't always successful and small or UNarmed uprisings are often put down, sometimes with lots of deaths. (Witness the Bonus Marchers' Massacre.) But recent decades of world politics have shown how effective a popular uprising can be, against even a coalition of world powers and superpowers.
If it came to that in the US, you can expect a substantial amount of the military (especially retirees) to be on the side of the people, along with lots of military equipment raided from armories. (You can see that now in the Middle East. The big difference between Al Queda and ISIS/ISIL is that the latter has bunch of colonels and other line officers, force-retired and blocked from normal politics in the wake of the 2003 invasion of Iraq and overthrow of the Ba'athists - along with a lot of seized military arms. The former is a bunch of terrorists, the latter has a substantial army.
California was debating requiring a serial number on home made guns independent of how they were made.
Actually, the legislature passed that. But, in a fit of sanity, governor Jerry Brown vetoed it.
Anyone familiar with California politics will realize how extrordinary that is. B-)
Seems like a big flock of pigeons over a big crowd would be an effective way to spread a virus that is contagious between birds and people.
Don't worry about Ebola, though. It doesn't do "airborne transmission". (Yet.)
However, the Ebola Reston strain is airborne though only dangerous to monkeys.
I have oftten wondered whether the Reston virus had mutated to be spread by things like sneezes, or if it might be another matter entirely.
A number of monkey species throw feces (and/or other bodily secretions) when under stress and perceived attack. (I don't know if this is one of them, but assume for the moment it is.) Might being confined to cages along with others provoke such behavior? Wouldn't a sick monkey's feces, and tiny particles separated by airflow during the flight, carry an ebola-family virus just fine, without any mutation to make it, say, shed into nasal mucus and be carried by a sneeze?
(Granted this might fit the literal definition of "airborne transmission". B-) )
Our government has backed an expensive and inefficient renewable energy tech - that's the only reason we're even having this conversation.
As opposed to our government backing an even more expensive and inefficient incumbent system?
By subsidizing solar power for domestic installations, that tax money is effectively being put back into the hands of the general public through savings, rather than into the coffers of multi-million dollar, often international corporations where it can further corrupt the system.
And I'd be happy to pay a "road use tax" even though I don't drive an EV (yet...). I figure I pay about $130/yr in gasoline tax, which if I switched to an EV I'd save about four or five times that easily.
If you can cite a study to prove your point you have won the argument.
That's not trusting science too much, that's laziness. Usually the person citing the study has a tenuous grasp of what it really says, and in all but a handful of cases they are betting on the fact that few people will bother to look it up and read it themselves.
You can tell this is what's going on, because it only further polarizes people; if the "study" reinforces their existing view, then it's the best thing ever, and if not then the scientists who did it are clearly corrupt or they're just plain wrong. No attempt to understand, nothing changes, just reinforcement of bias.
For starters, please provide citations for everything you put in quotes.
If scientists were so desperate for money, so easily bought by whoever was willing to pay them, we'd have volumes of studies saying that burning fossil fuels is good for everything from water quality to sex drive, that dumping toxic waste into rivers makes fish taste better, and that tobacco smoking curse cancer.
But we don't. For every study that suggests (or is construed to suggest even though it clearly doesn't) that climate change isn't occurring there's at least a hundred that says it is.
The best explanation I can come up with is that the scientists are not chasing paychecks like some people claim, but are doing their best to honestly study a subject they feel is important and are interested in.
I'm willing to bet that machine costs more than $1000 complete, and probably doesn't use belt drives for the axes.
Also, 230mm/sec is 13.8 meters per minute. And that's while extruding - I'd be genuinely impressed to see a mill that can do a cutting operation (not just move) at that speed.
3D printing was the result of a lot of researchers working on a lot of parts, and when the dust settled, none of them could build a really practical printer without paying off all the other patent holders, most of whom were playing dog-in-the-manger with their patents while trying to elbow out the competition.
You see that with a lot of inventions. They may go through several cycles of invention / related invention / non-conbination / wait / patent expiration until enough necessary parts of the technology are patent-expired that the remaining necessary inventions can be assembled in a single company's product and the technology finally deployed.
Thermoacoustics, for instance, just had its second round of patent expiration and is in its third round of innovation. The basic idea is to make a reasonably efficient heat-engine and/or refrigerator (or a machine that combines, for instance, one of each) with no moving parts except a gas. Mechanical power in the form of high-energy sound inside a pipe is extracted from, or used to create, temperature differences.
There are some really nice gadgets coming out of it, built mainly out of plumbing comparable to automotive exhaust systems and tuned manifolds, maybe with some industrial-grade loudspeakers built in, or their miniaturized or micro-minaturized equivalent. (Example: A hunk of pluming with a gas burner, about 12 feet high and maybe eight feet on a side. Oil fields often produce LOTS natural gas in regions, like big deserts, where it's uneconomic to ship it to market. It gets burned off and vented. (CO2 is weaker greenhouse gas than CH4, by a factor of several). Pipe the gas into the plumbing, light the burner, and it burns part of it to get the power to cool and liquify the rest. As a liquid it's economic to ship and sell it. Then you get to use much of the otherwise wasted energy, displacing other fuel supples and reducing overall carbon emssion.
I hope this is the cycle where things hit the market.
Patents don't matter for making a printer for your own use.
They can matter if you build a business on them, like by selling objects built using them.
Especially if they improve make your process cheaper, easier, more convenient, flat-out possible, or produce a better part. (And if there ARE cheaper, etc. ways to do it, why are you using the patented tech anyhow? B-) )
Patents in the US were about increasing innovation by making first mover advantage truump second mover advantage: Giving the little guy with the bright idea time to set up manufacturing, make back his costs, reap some benefits, and get established enough to compete with existing large companies once they expire. Without them, it was thought, the existing big guys with the infrastructure in place could quickly clone the little guy's new invention and out-compete him in the market, but they wouldn't bother until the little guy had proved it was worth the effort. This would suck the incentive out of the little guys, the big guys would have little incentive to improve, and progress would be slow-to-stalled. The short-term inhibition on others deploying the invention was seen as less of an impediment to progress than having most inventions not be deployed, or even made, at all.
The idea was to set the time limit to maximize progress to the benefit of all/the country, and make manufacturing and technology grow like yeast (ala silicon valley B-) ). Part of the intent was to bias it toward innovators and make established processes free to use, because when the country was getting started the established players were owned by foreign interests. The founders wanted the country to develop its own industry, rather than being dependent on, and sending most of the profit to, big businesses in Europe.
But the time was set for heavy manufacturing at the pace of the period. It's a horrible mismatch for, say, software: With the availability of general purpose computing platforms, able to make distributable copies at electronic speed and copyright to prevent verbatim cloning, a person or company with a new software product can go from steath-mode program development to market establishment, profitibility, and even market dominance in a matter of months, before competitors can engineer their own version. So patents aren't necessary to promote innovation, leaving just their retarding effect holding down the blaze of creativity. (Then there's open source, with its alternitive monitization and/or reward strategies. But that's a "new invention". B-) )
It seems to me that:
- The expiration of patents on stereolithography did help produce the initial explosion of new, and often inexpensive, devices and the improvements in what can be made, how accurately, and how inespensively.
- The availability of machines suitable for practical industrial prototyping - even before the cheap machine explosion - pretty much forced the high-end CAD software producers to include some form of stereolithography output format, while an open output format made the choice obvious. That's a big benefit to the toolmaker for a small effort. The availability in the high-grade commercial tools is a great synergy and helps a lot. But the hobby machines needed CAD tools and open source was already up to the task: Had the big players not gone along it still would have been done, and those big players not "with the program" would be experiencing major competitive pressure from open source tools and competitors that did provide such output.
And here's the key:
- The availabitiy of these rapid general-purpose maufacturing tools will bring (is already bringing!) software's high-speed innovation and entrepenurial models to the manufacture of physical objects. Patents could be shortened in term or reduced to "design patents" - the manufacturing equivalent of copyright - and produce a physical-product explosion comparable to the computer revolution. (Or patents, like "content" copyright, could become the tool of obsoleted established players in the suppression of the competing business models.)
Brace yourself for either the physical-manufacture ramp-up to science-fiction's "singularity" or an ongoing RIAA / MPAA / conglomerate - style legal battle.
What kind of machine is it?
I agree a teacup should not require support, unless the handle has a loop that dips below the attachment point. But even then only the underside of that loop would need support.
The layering can leave stripes, but a nice material with good print settings on a well made and tuned machine it's more of a texture than actual visual artifacts. They're like grooves on a record; you can feel the individual grooves but unless you look closely or get the light at just the right angle it just appears as a matte finish.
I've only printed an object intended to be liquid tight once, and it worked fine. Again, it comes down to print settings, calibration and good quality material.
So in the interest of improving your 3D printing experience, I'd like to know what machine you have, what material you use and what the settings are.
As for speed, that's also generally a limit of the material... but I've gotten mine up to ~230mm/sec before the heater in the nozzle couldn't provide enough power to melt the filament at that rate.
In practice you have a lot of moving mass which limits your top speeds on complex parts - the forces from accelerations can overwhelm the cheap belt drive systems most hobby-level printers use. Of course, if you want to shell out for better parts you can make something a lot better
I've been using the twirly type CLFs in a ceiling fan "glass ball" light for years (upside-down and enclosed, expressly against the manufacturer's warnings to not use them inverted in enclosed fixtures!).
In fact I've gotten into the habit of dating them with a sharpie before I install: Nov 2011. Since this is in my bedroom it's used for several hours a day, every day. Coming up on 10,000 hours, which is the rated life of the bulb, despite the warranty-voiding installation.
That said, the early generations of CFLs were absolute shit. Don't let that turn you off on the tech, and a few extra bucks for buy a decent brand is worth it.
So it's telling us just what we already knew? Interesting.
For three or more decades. (Before that some of the classes of things they're comparing didn't exist, with enough deployment, to characterize.)
On the other hand, it's nice to have it confirmed with some rigor and measures.
Oops. Typoed $/watt to $/kW in part of the above and accidentally hit submit rather than preview. My bad.
If Machiavelli were a hacker, he'd have worked for the CSSG. -- Phil Lapsley