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Comment: Re:I'd seriously think about a dedicated router (Score 1) 99

by LoRdTAW (#46785375) Attached to: Ask Slashdot: Which Router Firmware For Bandwidth Management?

I concur.

Been running m0n0wall for about 5 years on an Alix board and for many years before that on a P3 500. Never had to reboot it once. When my WAP54g started to flake out I replaced it with an Ubiquiti UniFi UAP which blows the old Linksys WAP54g away. The old 54g could barely push a signal 2 floors down to the kitchen, living room, and the basement was a dead zone. Now I have a strong signal throughout the house. It has a boat load of features and is 70 bucks on newegg.

I did not know about the APU.1C, thanks for posting that. The only thing is m0n0wall is not SMP aware, though it will run on an SMP system like the APU.1C. You are better off running pfSense which has SMP and 64 bit support. That board should have no issues pushing over 100Mbps while running multiple services and VPN encryption. My only concern is the use of Realtek gigabit chips. I wish there were Intel nics on there.

Soekris Engineering makes some pretty solid hardware but it comes at a price. The net 6501 has up to 2GB ram, single core Atom 1.6Ghz, 4 intel Gigabit ports, SATA, mSATA/USB, mPCIe and up to 2 PCIe x1 slots for actual PCIe cards. A top of the line 6501-70 and case will run you $470 without any accessories (storage, power supply, etc.). Before the 6501 came out I was going to buy a net 5501 but I couldn't justify the price so I went with the Alix.

Comment: Re:Materials (Score 2) 69

by LoRdTAW (#46716865) Attached to: Interviews: Ask Bre Pettis About Making Things

The problem is cost. The best process is sintering using either a laser or electron beam. Additive systems using a welding head are nowhere near accurate and very dirty in terms of smoke and soot. Sintering has its own can of worms including a cheap source of powdered or granular metals.

To sinter with a laser you need a laser and a box to put it inside of filled with an inert gas like nitrogen or argon. Nitrogen is cheap but people would have to buy or rent gas cylinders and keep up on getting new filled cylinders from a gas or welding supply company. Not exactly user friendly.
Now for the laser: A 500 watts cheap, compact, continuous wave laser would be needed but from my research, they don't exist. The ideal laser source would be a fiber laser. They are simply a cluster of LED's and the fiber that couples them together is the laser gain medium. The fibers then feed into a delivery fiber and off to the workpiece or yet another coupler to add more LED clusters. A CO2 laser would also work but they are bulky, inefficient and need a lot of cooling. I work with both NdYAG and fiber lasers so I know the industry. And the industry for fiber lasers is a patent minefield. So good luck getting a cheap 500+W fiber laser. Our 4kW IPG YLS-4000 ran us almost $300,000 including chiller, fibers and beam delivery head.
From the laser you need a galvo scanner to scan the beam around the powder surface. The galvo scanner might actually be an easy hack using cheap galvanometers.

Electron beam sintering. As crazy as it sounds, EB sintering is probably the better way to go. You don't need shield gas and the purity of a vacuum leads to higher quality parts. The only issue is again cost and bulk. You need a vacuum chamber of sufficient size and a decent pumping system including a high vacuum pump, either turbo or diffusion. Though I bet you could build one the size of a larger mini fridge. The electron gun is simply a tungsten wire or ribbon and the beam is deflected using what is analogous to the deflection coils in a CRT. And we all (well mostly) should know we can scan in the 10's of kHZ so printing can be very fast. A 60kV power supply of about 5-10mA would suffice (about 600W). All you would need to do maintenance wise is keep a stock of filaments, keep the chamber door seals clean, ensure your vacuum pump oil level is good and have plenty of powdered metal. The expensive part is the vacuum system could cost well over 10 grand.

Comment: Re:Off-roading? (Score 1) 172

by LoRdTAW (#46708061) Attached to: Land Rover Demos "Transparent Hood"

How many Land Rover owners actually off-road? Im guessing a small fraction of a percent. These cars are more of a luxury vehicle than practical offroader. The transparent hood is just a marketing gimmick to get people to buy a Land Rover. The main market for these cars are yuppies and soccer moms with money. They don't have to ford rivers, climb a steep hill or drive down muddy dirt roads after a monsoon to buy groceries, make it to their hair appointment or commute to work.

Comment: Re:Now it's the grid engineers' problem to solve.. (Score 1) 227

by LoRdTAW (#46685053) Attached to: Nanodot-Based Smartphone Battery Recharges In 30 Seconds

The gas stations would have to have their own substations and high voltage service to do 30 second electric car charges. And a typical gas station has about 8 pumps. So 80MW to charge 8 cars in 30 seconds is going to be a killer unless you run a 120kV ~400A service to the gas station. Overhead lines would be a no go in many areas and underground lines are super expensive to lay. All that for a gas station.

A single 10.2 MW "pump" would require 430A @ 13.8kV. Or run 69kV to the pump and have an 86A circuit.

A bit more practical would be to aim for 5 minute charges. People can just chill in their cars and wait for them to charge in a few minutes, offer them free wifi while they wait. That would require 1.02MW per pump so a station of 8 pumps at full load would draw about 69A at 69kV which is a bit more practical. Of course they would still need a sizeable substation to step the voltage down to 480V or 600V 3 phase for the chargers. And then each pump would need a 1000-1200A breaker and multiple large cables. Imagine the cooling necessary for the switching bank in each of those pumps, they would be enormous. A better idea would be to build service stations on top of a pit filled with the substation and chargers. Liquid cool everything and a simple pump looking terminal up top with the charge cable would be the only thing visible. The footprint would also stay the same and cooling towers be located on the roof of the service stations shelter canopy. Or large ducts could be built to circulate air through the stations electric pit. The only concern would be flooding but that would be solved in the planning stages.

And then think about how large a 1.02MW charger cable would have to be. From a quick google the tesla batteries are 375 volts. So to pump 1.02MW @ 375V you have a charge current of 2720 Amps. The thickest cables for building service are 2000 MCM which is about the thickness of a baseball bat and needs to be bent with a hydraulic bender. Using special high temp jackets and such they are only rated to 1800A. They would have to make thinner flexible liquid cooled charger cables or invest in superconductors to make them practical. That or instead of a cable an arm that can be easily positioned via a spring or motor assist with heavy copper bus bars inside or liquid cooled conductors. It would look like an industrial robot arm and even grandma could maneuver it.

Comment: Just need a bigger power supply. (Score 1) 227

by LoRdTAW (#46684625) Attached to: Nanodot-Based Smartphone Battery Recharges In 30 Seconds

If a 2000 ma/hr (2 amp/hr) battery supplies 2 amps for a full hour then we need to put the same amount of current in reverse to fully charge it. So a 2 amp charger can charge a (dead) 2A/hr battery in 1 hour. To do it in 30 seconds we need a heck of a lot more current. So a little math reveals that to charge it in a minute we would need 2A*60min = 120A/min charge current. And for 30 seconds we would need 240 Amps. Though I bet most people won't be charging stone dead batteries.

30 amps could charge a dead battery in 4 minutes. And the power supply wouldn't be that large, though it would have to be table top and have some heavy gauge cables coming out of it. Another issue is a new charge connector would be needed to handle the current. We might have to go back to charge cradles with large contacts.

Comment: Re:Answer... (Score 2) 88

by LoRdTAW (#46651795) Attached to: Amazon's Fire TV: Is It Worth Game Developers' Time?

Depends on where the developer thinks the money is. Ask anyone on the street if they have heard of Ouya. My bet is almost no one will know who or what Ouya is. Then ask them if they have heard of Amazon. I'm guessing a very large percentage, probably over 90%.

Amazon has tons of money they can devote towards marketing for such a device. Far more than Ouya could dream of. So one could surmise that FireTV will have far more exposure and therefore has the potential to become a lucrative platform. It's certainly worth the risk.

Machines certainly can solve problems, store information, correlate, and play games -- but not with pleasure. -- Leo Rosten