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Rob Davidoff
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104 followers
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I used to be frustrated because one of the formative books of my childhood wasn't available on Kindle: "The Collected Short Stories of Arthur C. Clarke." I had it in paperback, which weighs in at about 5 pounds, but was among my go-to books to re-read since I could pretty much be sure there'd be one story in it I hadn't read in a few months. I'd been hoping for it to pop up on Kindle, as it'd solve the weight problem.

Because the universe is mean, there's now two Kindle editions. One is by "Arthur Clarke" and one is by "Arthur C. Clarke". The former is $20, the latter is $16.50. I can't find a major different between the samples, so...I am very confused.

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Volume of the part, per the site, looks like about 5 cubic inches in seven hours with 7 thou (inches) layer resolution. More like a polymer machine than a traditional DMLM system in terms of resolution, which means I'm not surprised their surface finish isn't great. I wonder about their ability to slice parts, though, as this is a relatively simple toolpath.

Of course the other advantage is that that's a larger part than most DMLM powder-bed systems can handle, and the control on the head is more scalable in a way powder volume isn't.
Laser metal deposition manufacturing (LMD)
A 5 axis laser metal deposition manufacturing method developed by TWI for an EU-funded project which is demonstrating drastic time reduction in the manufacture of aero engine casings.

In LMD, a weld track is formed using metal powder as a filler material which is fed, through a coaxial nozzle, to a melt pool created by a focused high-power laser beam. By traversing both the nozzle and laser, a new material layer develops with precise accuracy and user-defined properties. The application of multi-layering techniques allows 3D structures to be created.

Watch:
https://www.youtube.com/watch?v=yKnlmfuMSgo

Reference:
http://www.merlin-project.eu/home/index.jsp
http://www.twi-global.com/news-events/case-studies/revolutionary-development-cuts-manufacturing-times-using-laser-metal-deposition-583/

#scitech   #engineering   #LMD  
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Honorverse tactical doctrine evolution, summarized:

Just got home from a week-long road trip of about 1500 miles--my first long distance trip in my Volt (2013 gray, code name "Danny Phantom") since I bought it used in March. Overall, it was a very good experience--I really enjoyed driving the car a long distance and the gas sustainer gave me a range and freedom to just drive that I might not have had in a Leaf: today alone we covered about 371 miles.

More to the point, though, looking on Plugshare as I drove makes me feel that the future where a full EV can compete directly with any gas car of the same class is coming sooner than many think--my Volt can only pull 120 or 240 Volts at a maximum of 15 amps, limiting me to about 6 range miles/hour charging from a wall outlet (as I was able to at almost every hotel we stayed at) or 15-odd rmph from a dedicated L2 charger. However, almost every hundred miles we drove on the trip I saw L3 chargers capable of pushing 20 or 50 kW--many shiney and new in the last six months, including at several of the motels (even some of the cheaper ones).

With my Volt's gas engine and places to be, it was generally more effective to charge when we had someplace we wanted to stop and walk around and just push on on gas otherwise than to stop for the three or four hours for a full charge every hour or so of driving--but those new chargers mean that the Model 3, Chevy Bolt, and next-gen Leafs that are coming within a year or two will all be able to stop and pick up a full 200-mile charge in the same hour we'd pick up 10 miles while we walked around Cocoa Beach.

Also, with the number of free L2 and L3 chargers I saw and the reputed several-thousand-dollar price of supercharger access for the Model 3, thinking seriously that the Bolt might fit my needs more than the 3. Stopped to charge at a Chevy dealership for a couple hours at one point to suck down a few kWh, and got to talking with the sales staff about my experience--as with other Chevy dealerships, the team seem very interested in their EVs and seemed to know a fair bit about the Bolt in spite of release being a good six months away. I might end up turning in Danny for a Bolt in a couple years, depending on how options for the 3 and the Bolt pan out, and what Nissan does with the Leaf. Either way, the competition is really good for those of us interested in a cheaper, more sustainable future rather than just Tesla fanboys. The more the merrier, and options to replace gas for every every price tag and market segment possible is a critical part of that.

tl;dr: I took a road trip in a Volt, almost entirely on gas, and came away more convinced than ever that the electric vehicle future is coming fast, and that this gas engine is the last one I intend to own in a car.

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"I wonder if it will be friends with me!"

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Wow.

+SpaceX launches in numbers:

3 for 3: Three landings in a row on OCISLY, two from GTO missions
4 of 6: Rate of F9-FT launches that have landed successfully. Both failures at least made it to the barge, though in SES-9's case in a somewhat Micheal Bay fashion.
5 in 5: 5 launches so far in the first 5 months of 2016
0: Cores reused from operational flights on a second mission...so far!

Keep counting!

Today I discovered my car is nuclear powered.

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This is my favorite April Fool's I've seen today. :)
#FirstLight! The ESA Operations flight team switched on the ExoMars TGO camera to acquire the spacecraft's first image from deep interplanetary space.
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+Alessio Sangalli, did you have a good view of Jason-3 today?
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