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Comment: Re:Seriously? (Score 1) 110

You can get away with that using smaller "park flier" planes as they are less able to cause damage, but there is risk involved. If you hurt someone you will be personally liable and wont be insured.

By comparison any official club will register with international model aircraft organisations. They train their members in the rules of safe flying, and provide insurance if something goes wrong. A few years ago my local club was $180 per year, not cheap but not too bad considering they have to maintain grounds as well.

Comment: Re:Does This Make Sense? (Score 1) 318

by aXis100 (#49643629) Attached to: Tesla To Unveil Its $35,000 Model 3 In March 2016

Crappy single phase AC motors have sucky low end torque because they dont have a second phase to produce and offset magnetic feild. They have to fake this second phase using capacitors, split coils, shaded poles etc, and those virtual second phases are quite weak.

Three phase AC motors have no such issue. They can produce high torque at low speeds, and can have quite consistent torque over a large range of speeds. This is perfect for a car as it gives you smooth acceleration.

Comment: Re:Haven't quite got my attention yet (Score 1) 318

by aXis100 (#49643595) Attached to: Tesla To Unveil Its $35,000 Model 3 In March 2016

A relatively cheap option for a controller is a 3 phase VFD (variable frequency drive) coupled to a three phase induction motor. Internally the VFD rectifies three phase mains to high voltage DC, so you just string up the batteries in series and it accepts the input power just fine.

Getting the regenerative braking to work is a bit harder though.

Comment: Re:Lead Acid (Score 5, Interesting) 317

by aXis100 (#49608683) Attached to: Tesla's Household Battery: Costs, Prices, and Tradeoffs

Im not convinced. It's good that you've rated that pack at 50% depth of discharge (48V x 400Ah = 19kWh nominal, approx 10kWh @ 50% DoD), but typically lead acid packs will only get 1000 cycles at that rate. You typically have to go to a 30% DoD to get 10 years / 3000 cycles.

Lithium can do greater depth of discharge for far more cycles. The overall lifetime costs of lithium per kWh were already starting to beat lead acid, and the new Tesla pack is even better.

Comment: Re:Thinking . . . High Speed Trading Code (Score 1) 84

Stuff minutes. Make it hours or even a whole day. Anything less is speculation.

The stock market should be promoting real investment - i.e you do some research and have an educated opinion that a company will do well. You buy shares, wait for the returns and then sell when things have stabilised. That process takes time - months or years even.

Comment: Re:The 3d printed elephant in the room (Score 1) 52

by aXis100 (#49332433) Attached to: Australian Company Creates Even Faster 3D Printer

The commonly used ABS plastic used in FDM machines is very durable, but the orientation of the print matters. You do have to design the prints so that the weak join between layers doesnt experience stress.

I do agree with the looking horrible part, but you can do funky things like acetone dips or acetone vapor to smooth and gloss them.

Comment: Re:They indeed look very much like incandescents (Score 1) 328

by aXis100 (#49246399) Attached to: New Crop of LED Filament Bulbs Look Almost Exactly Like Incandescents

That's got nothing to do with the LED and everything to do with the driver electronics. Unfortunately the packaging they are in limits the size of the driver circuitry significantly so i guess it's going to be more common with these filament bulbs.

Comment: Re:B.S. Alert (Score 1) 88

That's a bit harsh and fails to see the significance.

From the article: "There are no analog circuits, no filters, no chokes, none of the traditional circuitry and components expected in a radio transmitter."

If it can be built as an peripheral chip, it can also be built onto the same silicon as a microprocessor.

Comment: Network file transfer (Score 1) 466

by aXis100 (#49143381) Attached to: Ask Slashdot: Old PC File Transfer Problem

Windows 3.11 machines were capable of SMB file sharing over a network. You should be able to use an old PCMCIA ethernet card and install the Microsoft TCP stack (it wasn't installed by default), then see other computers over a workgroup.

If that sounds too hard then serial transfer over null modem should be the easiest and I'm sure I did it many times myself back in the day. I cant remember what software I used to use, googling for Windows 3.11 serial file transfer shows lots of hits though.

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