Thursday, May 31, 2018

Genuinely New Ideas in Rocketry Are Rare

Vanishingly rare.  I don't know if this is the first time it has ever been discussed, but according to the website, a collaboration between two universities is researching a booster that literally consumes itself on the ascent to orbit. 
In a paper published in the Journal of Spacecraft and Rockets, engineers from the University of Glasgow and Oles Honchar Dnipro National University in Ukraine discuss how they have built, fired, and for the first time throttled up and down an 'autophage' engine which could change how small satellites are sent into space.
'Autophage' translates as 'self-eating', and the concept is that instead of fuel tanks and the superstructure that the booster provides, a vehicle powered by an autophage engine would consume its own structure during ascent.

A typical booster, like the Falcon 9 boosters that SpaceX recovers and reuses, contains liquid fuel and oxidizer tanks along with plumbing to connect those tanks to the booster's nine engines   Big boosters tend to be liquid fueled, with notable exceptions for the large solid rocket boosters used in the Space Shuttle program, and large vehicles like the Delta IV Heavy.  Typically, the booster's weight is several times the weight that can be delivered to orbit.  For every pound of weight added to payload, the vehicle has to carry more fuel, and the fuel to lift that fuel. If the booster's weight was usable fuel that would be an incredible advance. 

The autophage engine concept allows weight from the plumbing tanks and other essentials to go into larger cargo capacity.  If the same technology were to be in upper stages, less debris would survive to make it into space.  No boosters (or less junk) to recover or dump in the ocean; and less debris from upper stages.  More efficient from all perspectives.
The autophage engine consumes a propellant rod which has solid fuel on the outside and oxidiser on the inside. The solid fuel is a strong plastic, such as polyethylene, so the rod is effectively a pipe full of powdered oxidiser. By driving the rod into a hot engine, the fuel and oxidiser can be vaporised into gases that flow into the combustion chamber. This produces thrust, as well as the heat required to vaporise the next section of propellant.

Simply by varying the speed at which the rod is driven into the engine, the researchers have shown that the engine can be throttled – a rare capability in a solid motor. Currently, the team have sustained rocket operations for 60 seconds at a time in their lab tests.
I'm having a difficult time visualizing how this could work.  The vehicle has a "combustion chamber", or chambers, so some structure needs to last the entire time it's burning to hold the combustion chamber and engine nozzle(s) in place.  If some control or telemetry to the ground is involved, that will have to be in the booster just as it is now, and will get thrown away, too.  If the autophage motor is just burning along the length of the body, it's not that different from any solid rocket motor; those tend to burn from the center outward along the entire length of the body.  Having the ability to throttle the engine up and back is unusual.  Solid motors are typically said to burn until they burn out.

The researchers describe it in starkly different terms than I do and don't address my thoughts at all.  Dr. Patrick Harkness, senior lecturer at the University of Glasgow's School of Engineering, puts it this way:
"The propellant rod itself would make up the body of the rocket, and as the vehicle climbed the engine would work its way up, consuming the body from base to tip.

"That would mean that the rocket structure would actually be consumed as fuel, so we wouldn't face the same problems of excessive structural mass. We could size the launch vehicles to match our small satellites, and offer more rapid and more targeted access to space."

A small autophage motor at the University of Glascow.  University of Glascow photograph.

Wednesday, May 30, 2018

Ignore That Financial Mess in Europe, Roseanne Tweeted Something!

Is it 2006 all over again?  Is the economy truly better or are we just seeing the effects of a few local, isolated actions.

Maybe you didn't see the story that Italy is slipping into a financial crisis, but you might have seen the US stock market dropped about 400 points on the Dow.  Italy is why the Dow dropped.  Tokyo's NIKKEI and Australia's ASX200 were also hit by Italy's troubles yesterday.

At root is the same problem, the same rot affecting every country from US to China; Germany to Greece.
Italy risks careening into a new financial crisis after the Bank of Italy said the country’s leaders could not “disregard” financial constraints and its commitments to Brussels.
Escalating worries that Italians may be poised to take a tougher stand against the euro prompted a round of accusations and finger-pointing among EU officials, including a rare admonishment by Donald Tusk, the European council president, who said EU institutions needed to show “respect to voters” in Italy.
In October of '16, I posted an introduction to some of the players in the mess today, as well as a "keep your eyes out" for things going on Italy.  It centers on the 5S Movement, which began as joke and turned into a populist, "Brexit-like" party movement.  iExit?  The latest issues appear to stem from a need to form a "coalition government" between differing parties and their inability to do so. 
The crisis was set off late last week when the Five Star Movement (M5S) and Lega, which had been attempting to form a government, insisted that the president, Sergio Mattarella, approve their choice for finance minister, Paolo Savona, a fierce critic of the euro. Mattarella vetoed the nomination and the incoming populist government collapsed before it had taken power.

The president appointed a new prime minister, Carlo Cottarelli, a former director at the International Monetary Fund, who was expected to present a list of ministers to Mattarella on Tuesday. The president’s spokesman said after a meeting that the two officials would meet again on Wednesday morning.
Add in that the European Central Bank is struggling to keep control in the country, and you get quite a mess.  Ignazio Visco, chairman of the Bank of Italy, said the country was at risk of losing the “asset of trust” with investors.  On Tuesday the Italian bond spread, a leading indicator of investor concern, rose to its highest level in four years.

Italy is the third largest economy in the European Union, behind Germany and France (and I'm leaving out the UK due to the ongoing Brexit).  If Italy were to collapse or go into a deep economic crash, it threatens the entire EU.  Italy has one of the largest national debts in the world and an unemployment rate over 11%. It's economy is now worse off than it was before 2007. The Italians tried, like everyone else, to borrow and spend their way out of the financial crisis, but they never recovered.

The fundamental problem, as I must have said at least five hundred times in the 2800+ posts of this blog, is that the world is awash in debt.  The total debt in the world now is $164 trillion.  Annual world GDP is in the vicinity of $70 trillion so this is well over two years worth of "all the money in the world" to pay off that debt.  That figure ($164 trillion) is not counting the unfunded liabilities in the world's economies, which currently add about $115 trillion in the US alone, as can be found on the Debt Clock.  Unfunded liabilities shouldn't be counted as debt; we haven't spent that money yet. They're more like a promise to spend in the future, however if we can't meet our liabilities now and can't live with a balanced budget it's reasonable to question where that money will come from. 

In the wake of the "great recession" of 2008, the world's central banks went on a stimulus binge like the world has never seen.  Not just the trillions of dollars created out of thin air here in Quantitative Easings; think of China's bridges to nowhere and ghost cities.  If anything, China has worse economic problems than we do.  All the central banks: the Bank of Japan, the European Central Bank, the Central Bank of China: all of them have created money from nothing. 

The US economy has shown some positive reactions to Trump's tax cuts and the news has been mostly good.  The labor participation rate hasn't improved to any noticeable extent since the middle of Obama's second term, though, still on par with the rate in 1978, and I honestly don't know what's up with that since we keep hearing about record low unemployment and other good news.  I note that some aspects of the Dodd-Frank banking regulation bill have been cancelled.  I personally never heard anything good about Dodd-Frank from any financial writer who seems to know the industry, so I view that as good. 

The world, I believe is in a precarious position economically.  Am I just a "too small thinker" to live with a world that measures debt in the hundreds of trillions pf dollars?  Could be.  On the other hand, I don't believe we're immune to any form of economic problems, and I still believe what can't go on forever won't go on forever, because I still believe that infinity is a very handy concept in math and science, but a rotten way to run an economy.

As for when this may happen, I've given up on guessing.  I've posted so many "real soon now" warnings in the life of the blog that I think decorum tells me I should say no one can predict it.

Italian actor and comedian Beppe Grillo; originator of V-Day and the M5S party.  Getty Images.

Tuesday, May 29, 2018

Rev 2 is Mostly Ready

Revision 2 of the cylinder for my Duclos flame eater engine, to replace the one I destroyed Friday, will most likely be ready to put back on the mill tomorrow.  I expected to get this one in a small fraction of the time spent on the first, since most of the time spent on the first one came from trying to figure out how to do certain things with tools I have (instead of immediately buying more new tools) and it did.  I spent about a week of "4 hour days" working on the first one, and about three of them on the second. 

It's not quite done.  The narrow diameter on the right needs to be reduced a little to press fit the pedestal onto this, and it needs to be cut off the extra rough stock that you can see in the lathe chuck on the left (wrapped in thin cardboard).  The same tool that made the fins on the cylinder will be used for that.  Most likely.

The truly detail-obsessed* among you will notice this one is different from the other, which is to say I also learned from my mistakes.  If you count, you'll see this one has nine fins; the other had seven and a smidgen of an eighth.  The print I'm building-to shows the slots and fins both being 3/32 wide (.0938").  On the first one, I just advanced the cutting tool by twice that and expected it to turn out.  I ended up with tolerance buildup - most of the fins and spaces ended up 7/64 wide.  This time, I had the idea to use the blue layout fluid (you can see a little remnant of it in the pic) and layout where edges should be.  Then I marked the edge of a space (between fins) by cutting a couple of thousandths deep; it allowed me to measure how wide the fin would end up and I could move the edge to make sure the fin was really .094 wide.

There are other small differences that I won't get into.  Think of it as a challenge.

I expect to spend more time agonizing over the setup with a dial indicator, verifying that it's the same height everywhere, and maybe putting a foot long pipe on the vise handle to clamp it tighter.  Basically, all the little tricks I've come across will get used, unless they contradict each other or something else.

( * "detail-obsessed" sounds better than "anal-retentive" doesn't it?)

Sunday, May 27, 2018

Memorial Day 2018

I know that for a lot of the country, Memorial Day is the unofficial start of summer and there will be cookouts and parties at the lake or beach or park.  Allow me join the chorus of folks saying that while you're enjoying your day, be it beach, barbecue, pool or whatever, take a moment to remember and thank those who have given their all in service to us.  Some don't get the chance to have that cookout, or be with their loved ones. 

There's a couple of pictures that I regularly run for Memorial Day, and this year I'm going to go with the image from 2011 that touches me by having an element of the unexpected. The images of women who have lost their husbands are gut-wrenching, but a dog isn't generally expected to have feelings this deep.  I went looking for the a photo credit and I found one this time.

In a final act of loyalty, Hawkeye, the dog of slain Navy SEAL U.S. Navy Petty Officer 1st Class Jon T. Tumilson walked up to his fallen master’s casket during the funeral in Rockford, Iowa, and then laid mournfully down beside the body for the rest of the proceedings  [Note: Petty Officer Tumilson was one of the 30 killed in Afghanistan in the shoot down of Extortion 17 which the families blamed squarely on the Obama administration - SiG]
Far too large a portion of the ruling class could use Hawkeye's loyalty.  There are signs that's improving, no matter if it's temporary or not.  The others could ponder showing less humanity than a dog.  

No barbecues for us.  We're still under the clouds associated with that Tropical Storm over in the Gulf. 

And ... It's Ruined

The cylinder of my flame eater engine, that is.

The last thing I mentioned in that post was planning to make a set of thinner, taller jaws for the vise because the existing set was grabbing it below the centerline by a little over a quarter inch.  That creates a force to push it vertically out of the vise - or cuts a notch into the fins.  The SHCS that came in the vise were too tall to use on anything much thinner than the factory jaws, so I found some low profile button cap screws to order.  I figured I could thin the jaws by about an eighth inch on both sides, giving me a quarter inch more opening.  Oh, yeah, I ended up leaving the soft jaws 1-1/2" tall. I might lower that a little.   While waiting for the screws to arrive, I made the jaws out of some quarter inch thick plate I had.  They fit perfectly.

So now it was time for a test fit.

Seemed like it was all good. The gap between the bottom of the cylinder and the vise jaw figured to be 1" and I had a left over block of 1" bar stock.  (Look on the left between the closest jaw and the cylinder).  It felt very secure. It took me a while to figure out how deep to cut the fins and the 1-1/2" diameter part of the cylinder over on the right end because it's never really specified on the print. The print does show that the flat should be 1" wide, so a little geometry (and an online calculator) showed me I ought to cut it  0.190 - about 3/16" deep.  (Seriously - how deep do you cut that?  I think this is similar to what's called Geometric Dimensioning and Tolerancing, or GD&T. )

A friend convinced me to put an extra clamp across the top - I guess he was afraid of aluminum jaws replacing 3/8" steel - so I added that. I cut the flat over the base of the cylinder in a few cuts, .025 deep at at time (3/8 end mill) and it went very well. Which led me to decide to take off the 3/32 wide fins in a couple of passes. First pass at 0.100 depth followed by a second pass at 0.190. When I was done cutting off all the fins I thought I'd move the end mill toward the base as a spring cut (a second cut with the same settings; it removes some metal that gets compressed by the cutting forces in the original cut and "springs back" to a higher level), just to level out any cutting marks. Instead it dug in and ripped the cylinder open. Look at the shelf on the end where I stopped the cut. That's a deep cut at the far end. 

You can see how bad it is. The Z axis on the mill never went below -0.190", so as I moved right to left along the cylinder cutting the fins off, the cylinder must have pivoted and lifted the left end. I sure couldn't see it happen. You can measure the diameter to the flat by putting the calipers on the fin and the flat at both ends. The end closest to the camera is 1/16" smaller than the end by the pedestal. The flat spot on the right end of cylinder after the fins was supposed to measure 1.000 and measures exactly that. Like I say, the entire piece was cut with the EM never going deeper than -.190".

In the aftermath of trying to figure out what went wrong, I focused on the idea that the cutter was getting lower as I made the cuts, which were right to left in the pictures here.  To cut off the fins (3/32 or .094 wide) I raised the Z-axis of the mill from -.190 to -.100, moved to the next fin, made a cut, lowered the cutter back to -.190 and took another pass.  As a diagnostic, I set an indicator on the spindle, raised and lowered the cutter back and forth between -0.100 and -0.200 about 40 times.  The indicator never showed a change in position, which means the cutter wasn't getting lower every time I raised and lowered the mill's headstock. 

My guess is that the cylinder pivoted because even with the taller jaws and the 1" bar stock spacer, the contact area holding it is still pretty small.  Theoretically, the contact is only a line with one point on each fin; practically, the metal will spread out a little, but it's still a tiny contact area.  Since the cut is deeper on the left, that means it was rising into the cutter, pivoting around the right end.  There wasn't enough holding force to keep the cylinder from rotating. Maybe I should have made really light cuts? Maybe something between the jaws and the cylinder to keep it from sliding, like very light sandpaper or cardboard?

This was Friday and I've begun work on the replacement cylinder.  I don't see any way I could fix this one.  Maybe with welding equipment and an expert's touch, neither of which I have, but I do have more pieces of 2-3/8" diameter bar stock cutoffs that I can make into the new cylinder. 

I'll be the first to admit that my main problem in doing machine shop work is that I Know Nothing.  Well, not quite nothing, but I'm totally self-taught and when you're self-taught there are always holes in your knowledge.  If anyone sees this and has ideas on how not to make this screwup again, let me know! 

Saturday, May 26, 2018

A Visitor to the Backyard

We had a visitor to the yard that we've never seen before. 

That thing it's standing beside is the outdoor half of a mini-split air conditioner in the workshop.  Mrs. Graybeard was out looking at setting up to do some cleaning and noticed him.  There was another on a neighbor's wooden fence not 6' from us. 

Neither of us knows a hoot about owls, but this appears to be an Eastern Screech Owl.  Everything about habits and habitat seems to match up.  This is a corner of the lot where three neighbor's trees overlapping turn it into a fairly dense wooded spot.  The fact that they're supposed to be nocturnal and daytime sleepers explains the tired-looking eyes. 

Friday, May 25, 2018

Sometimes the Jokes Just Write Themselves

Machine Design's daily email brings news that Dyson, the company famous for its vacuum cleaners, is going after the electric vehicle market.  They're doing it by way a new technology, which they may be the first to bring to market: solid electrolyte batteries.
This past February, James Dyson made the decision to build more than just high-precision vacuums and fans and instead focus on electric vehicles (EVs). Dyson plans to construct three EVs by 2020, the Financial Times reported, [paywall] with an estimated $2.8 billion project. Much like Elon Musk, Dyson looks to shake up the EV market by using solid-state batteries instead of the lithium-ion versions.

According to the Financial Times, the trio of cars would be non-sports car high-end models which would scale in production aimed toward the mass market. The vehicles will be constructed out of light materials just like the BMW i3 EV carbon fiber body. The key is the solid-state battery which, theoretically speaking, will be able to hold more of a charge compared to lithium-ion batteries.
Solid electrolytes?  The electrolyte in a battery has one main function: to conduct the electron flow from one plate to the other.  In a lead-acid car starting battery, for example, the electrolyte is a conductive solution of sulfuric acid in water.  In "dry cells", the electrolyte is in the form of a paste.  Liquids or pastes work better than any solid currently known.

Although they never directly say what the cathode and anode (negative and positive plates) are in the battery, they claim a solid electrolyte battery will be smaller and higher energy density than existing batteries, as well as being safer and longer lasting.

It might be the reason they don't describe details of the battery is because they don't exist, yet.  At least not outside the lab, in industrial quantities. 
Currently, finding the right material for solid-state batteries is key. According to Axios, Samsung and Dyson have collectively invested $65 million in Massachusetts-based Ionic Materials. The firm claim to be making progress into the technology. Its new material, a liquid crystal polymer, may be able to solve many of the current issues of mass production.

Ionic Materials claims that lithium ions move as fast or even faster through their polymer than they would through a conventional liquid electrolyte system. This helps demonstrate the stability of the company’s polymer material. Second, the polymer works at five volts and can be made simply and cheaply. Third, while most materials in solid-state research operate at about 60°C (140°F), the firm’s material works at room temperature.
Axios points out that the right material to use for a solid electrolyte battery is lithium metal.  Pure lithium metal is highly energetic, and would add something like 30% more capacity to today's state-of-the-art electric car batteries.  Lithium just also has the unpleasant characteristic of exploding or catching fire if it comes in contact with moisture.   Ionic Materials claims they've developed a liquid crystal polymer that conducts electrons as well as a liquid but doesn't make the lithium do nasty things.    
The article opens by suggesting Dyson looks to shake up the electric vehicle industry by using solid-state batteries in its 2020 car lineup. Since the batteries don't exist and we're half past 2018, I'll say no, they won't.  2021?  Maybe.

Dyson's EV, the car from the company that makes things that suck.  The Vroom-ba? 

Thursday, May 24, 2018

Dolph Lundgren is More Qualified to be "The Science Guy" Than Bill Nye

Ran across this the other day.

They're all entertainers, it's just that Dolph Lundgren is more qualified to be "The Science Guy" than Bill Nye is.  And punk rock singer/rhythm guitarist Dexter Holland is a good contender, too.

Who'd you rather have: the MIT Fulbright Scholar, the Doctoral student in Viral Oncology and Proteomics, or "Bill Nye - the arrest everyone who disagrees with me guy"?   

Wednesday, May 23, 2018

Turning the Hardest Known Abrasive Into a Dry Lubricant

Diamond.  The world's hardest commonly available mineral (yes there are harder oddities that have never been synthesized in industrial quantities, as diamond has) and a favorite abrasive for as long as they've been known.  Diamond coated tools are widely used in industry, and I personally think the whole "granite kitchen counter" movement couldn't have happened without widely available diamond tools.

So when I think about diamond, I think about uses as an abrasive; perhaps a coating on a machine tool.  I'd never think of it as lubricant, but according to Machine Design some researchers at Argonne National Laboratory have found just that.  When they mixed molybdenum disulfide, commonly used as a lubricant in high temperature applications, with tiny diamond particles they call nanodiamonds, the diamonds turned into a form of carbon that creates a nearly frictionless lubricant that essentially doesn't wear out. 
The most commonly used solid lubricants on the market today take the form of graphite paste. They are used as lubricants to grease doorknobs and bike chains, among other things.

In 2015, one of the researchers, Anirudha Sumant, made a breakthrough in solid-lubrication technology by demonstrating superlubricity (near-zero friction) at engineering scale for the first time by using graphene combined with nanodiamonds. This approach was revolutionary, and since then his group has continued to further develop the technology.
Graphene, of course, is one of today's "wonder materials" that's being researched for just about everything.   Its structure is essentially the same as graphite's, in that it's two dimensional hexagons of carbon atoms in sheets looking much like atomic-scale chicken wire.  Unlike graphite, it forms large, continuous sheets a single carbon atom in thickness but of macroscopic sizes. 
Most recently, Sumant replaced graphene in the process with molybdenum disulfide to see how other materials would behave. He was expecting the process to resemble the one observed with graphene-nanodiamond lubricant. However, the team was surprised when they couldn’t see nanodiamonds in the material. Instead, they found balls of onion-like carbon.

The molybdenum disulfide was breaking up into molybdenum and sulfur and reacting with the nanodiamonds to convert them into onion-like carbon. Onion-like carbon consists of several layers of spherical graphitic shells that can be used as a dry lubricant. And the process of combining molybdenum disulfide and nanodiamonds automatically creates this form of carbon without any additional chemical application. The lubricant is also self-generating and readjusts itself continuously, so it lasts longer.

These carbon balls sustain high contact pressure and, due to their unique nanostructure, glide easily, creating superlubricity. The team concluded that the sulfur diffusion increased the strain in the nanodiamonds, subsequently breaking them and converting them into onion-like carbon.
The term "onion-like carbon" is one I've never heard; I imagine something like shells of something like graphite arranged similar to the layers of an onion.  They estimate the friction of this combination to be 1/10 of fluropolymers (I assume they mean Teflon and similar), which means moving parts will perhaps last 10 times longer before wearing out.   They also point out that there won’t be any hazardous liquid residue or the need to use and dispose of rags as part of the clean-up process (no word on its toxicity to parrots).  Machine Design speculates it could also be used to make parts that can’t be made today, especially with metal stamping.
While molybdenum disulfide is a bit more expensive than graphene, less is needed in this process.

“The amount is so small — a few drops for kilometers of sliding — that cost is not an issue,” Sumant said.
I suppose it's the counterintuitive result that adding a fine abrasive to an ingredient used in grease creates a better lubricant rather than grinding paste that appeals to me about this story.  Argonne National Laboratory already has three patents on the superlubricity technology, with a patent pending on this breakthrough, and will soon be licensing the technology. 

The formation of the "onion-like carbon"; the left picture shows the nanodiamonds (brown) lying on the molybdenum disfulide sheet, then being wrapped up in the MoS2, and eventually turning into the "OLC" on the right.  Full story in their paper in Nature

Tuesday, May 22, 2018

Publix Ruins Graduate's Proudest Moment

One of the proudest moments in young adult's life is when they graduate high school.  Especially if they're an honors graduate.  Doubly especially if they graduate with highest honors. 

Such was the case for Jacob Kosinski of Charleston, South Carolina.  Of course, you'll know that you've made that grade before the graduation, and his family, some from out of town, came to his graduation and party.
His whole family, many from out of town, saw the Charleston, South Carolina, student graduate from his Christian-based homeschool program with a 4.89 grade point average and the coveted honor of summa cum laude.
His mom ordered a special graduation cake from her nearest Publix, which lets customers build their own cakes complete with a customized inscription, which they enter into a little message box.
Carefully, she typed in the message she wanted on the cake: "Congrats Jacob! Summa Cum Laude class of 2018."

The Publix software was unhappy with the word - cum. In Latin, cum is the preposition "with," as in summa cum laude "with the highest distinction." To the little box on the Publix website, however, the word meant something else and its sophisticated algorithm, alert for naughty words, returned a little message that said "profane/special characters not allowed." It substituted three hyphens for "cum."
It was the algorithms, of course.  Jacob's mother, Cara, said she filled out the request online, including a form that had a section for "special instructions" for the bakery.  She explained that Summa Cum Laude was a Latin term for high academic honor and was not profane, so she was concerned something like this might happen.  She even included a link to a website explaining the meaning of Summa Cum Laude and said she didn’t think much about it afterward.  Until the cake was opened at Jacob's graduation party. 

Jacob's mother was shocked and disappointed, saying, "I can’t believe I’m the first one to ever write "Summa Cum Laude" on a cake."  Maybe not, but maybe yours was the first order this crew ever got that said it.  

Publix offered to re-do the cake, but it was too late for that, so they gave her a $70 refund for the cake and a store gift card.  Jacob, for his part, is getting ready for college in the fall. 

Monday, May 21, 2018

NASA/JPL Planning Autonomous Helicopter Drone for Mars 2020

This is a mission that brings back memories of bold missions in the past.  The next Mars rover, to be launched in 2020, will bring an autonomous helicopter; the first mission in history to bring a flying, heavier than air vehicle to another world.
The next iteration of the Mars rover has similar design features to the Curiosity rover currently exploring Mars, however it is more technologically advanced than its predecessor. The new rover will have seven new instruments, redesigned wheels, and be more autonomous. However, the standout feature of the new Mars 2020 rover is the Mars helicopter—the first of its kind. It is small, autonomous, and will help demonstrate the viability and potential of heavier-than-air vehicles on different planets.
Designing a helicopter to fly on Mars is a challenge; the air is a tiny fraction of the density of the surface atmosphere here on Earth.  According to Mimi Aung, Mars Helicopter project manager at JPL, the surface atmosphere on Mars is like being at 100,000 feet here.  That's well beyond the service altitude of Earth bound helicopters and a couple of times the helicopter altitude record.

The helicopter system took four years to design; it's electric, powered by two motors totaling 220 Watts, and running on Lithium Ion batteries charged by its own solar panels.  It's also not much in the way of performance, according to the Machine Design article, which only says it, “can make short vertical climbs of up to 10 ft and hover for about 30 sec.”  Anyone with battery-operated tools knows well about the trades of battery life vs. size and weight. 
The aircraft weighs less than four pounds and its fuselage is the size of a softball. It has twin counter-rotating blades and will rotate at 3,000 revolutions per minute (rpm), about 10 times the rate of a helicopter on Earth. The helicopter contains its own instrumentation to explore Mars, including solar cells to charge is lithium-ion batteries and a heating mechanism to warm it in low-temperature situations. The helicopter will be launched once the rover reaches a suitable location and its batteries are fully charged. The hope is that the helicopter will be lead to future low-flying scouts.

In case you missed this hard physics reality in The Martian, Mars is light minutes away (how many depending on exactly where the two planets are in our orbits).  As Project Manager Mimi Aung said,
"We don't have a pilot and Earth will be several light minutes away, so there is no way to joystick this mission in real time," said Aung. "Instead, we have an autonomous capability that will be able to receive and interpret commands from the ground, and then fly the mission on its own." 
All helicopters balance lift created by the rotor vs. total weight, but lift depends on the atmosphere and as was said, Mars doesn't have much of an atmosphere.  In the designer's favor, though, it has less gravity (about 3/8 of our surface gravity).  The response was to focus on removing weight rather than developing larger rotors.  The embedded video shows the little drone lifting off in a pressure chamber, presumably matched to Mars' thin atmosphere.

Mars 2020 is scheduled to launch on a United Launch Alliance (ULA) Atlas V rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station, and is expected to reach Mars in February 2021.

NASA/JPL illustration.

This is Post #2800 In This Blog's Life

Just for fun, one from the emails.

Sunday, May 20, 2018

The Move to Make the Electoral College Irrelevant

Just like all the insane "resistance" movement going on in society, refusal to accept an election if your preferred candidate doesn't win, the move to overthrow the electoral college system is still pushing on.  We kind of talked about this in March, but the Daily Signal updates us on a vote from Connecticut to counter their voters.
Opponents of the Electoral College achieved an important victory last weekend when Connecticut’s legislature passed the so-called National Popular Vote compact. Democratic Gov. Dannel P. Malloy is expected to sign the measure.
States that approve this legislation enter a simple compact with one another. Each participating state agrees to allocate its electors to the winner of the national popular vote regardless of how its own citizens voted. The compact goes into effect when states holding 270 electoral votes (enough to win the presidency) have agreed to the plan.
Most of us haven't heard of this "National Pact", by which states potentially counter the will of their voters.  Author Tara Ross points out they're almost two thirds of the way to locking up the necessary 270 electoral votes to win the presidency.
[Counting Connecticut] 11 states and the District of Columbia have now approved the measure, giving the compact a total of 172 electors. It needs only 98 more to reach the 270 mark.
It's inevitable that, at some point, the state will vote for a Democratic candidate (it's Connecticut after all) and a Republican will win the national popular vote.  When that happens they will counter the will of the majority of their voters to change their electors over to the Republican.
What would Founders such as Roger Sherman think? That Connecticut statesman was an influential delegate at the Constitutional Convention of 1787. The Great Compromise—sometimes called the Connecticut Compromise— which gave Congress its bicameral structure, might never have been brokered without him.

Moreover, Sherman was one of many delegates from small states who refused to go along with the idea of a direct popular vote for the presidency. He knew that little Connecticut would be outvoted time and time again.
Recall that Hillary won the popular vote by a little over 2 million votes.  In the 5 counties that encompass NYC, (Bronx, Brooklyn, Manhattan, Richmond and Queens) Clinton received well over 2 million more votes than Trump. (Clinton only won 4 of these counties, Trump won Richmond).  Why would any candidate visit a state like Connecticut?  Why wouldn't the next Democrat candidate just rent an apartment in New York City or El Lay and mostly stay there.  Work harder in those big population centers to reach a few more voters who lean toward you anyway rather than build a diverse coalition.  Or to quote myself from March:
Whether they know it or not (and I assume they do know it), the desire to get rid of the electoral college is a desire to avoid those icky flyover-country people (with their bibles and their guns!) and have candidates just campaign in a few big cities.
One thing we can be sure of.  If this becomes law, and passes the Supreme Court, you can bet that there will never be any effort devoted to the issues affecting people in flyover country.  There will never be another minute wasted (after the primaries, which are state by state) talking about any of the concerns of any state less than the top third of the national population.  

Our country was designed to protect the small states from the big ones, and to protect the minority from the majority.  The bicameral legislature with one house's representation proportional to population and the other equal representation is just one example.  The electoral college with its incentives for presidential candidates to build broad-based coalitions is another.  There is a full-time, well-funded effort to destroy that. 

Saturday, May 19, 2018

A Partially Done Part

I've been continuing work on my flame eater engine which I post about regularly.  The next part is machined on both the lathe and the mill, and today I took it out of the lathe to move to the mill for the rest of the operations.   Before that, I grabbed a quick picture.

The engine pedestal, the first part I built, pressed onto the base easily.  It can be wiggled off with a bit of effort but I'm not sure that's a concern. I could remove that concern with a drop of red LocTite.   (It was never on the cylinder while the lathe was running)

When I went to put the the the part in the vise on the mill, I found it doesn't really fit.  The vise jaws are too low profile,  and the vise barely opens wide enough.  A quick unplanned side project to make a couple of temporary jaws for the vise is jumping in front of this.  While I'm at it, I'll make these thinner than the current steel jaws (.390 thick).  By changing the mounting screws, I can reduce the jaw thickness s to .250, each, which will pick me up a little over an eighth on both sides, so a total of a quarter inch.  Instead of the current 15/16" height, I'll make them about 1-1/2 inches tall, which will put better pressure on the side of the cylinder, which is 2" in diameter. 

I never know exactly how much detail to put into these posts, because I never know what kind of readership there is.  I don't see any sense in telling you about every 1000th of an inch on every cut, but rest assured I need to pay attention to them. 

Friday, May 18, 2018

Nuns Putting Pressure on Publicly Held Gun Companies

Perhaps you saw the statement from Ruger within the last week or so, saying they have to prepare a report because of a shareholder vote but they will not change their business.  If you missed their statement, I repeat it here:
Please understand that Ruger was obligated by applicable law to include a shareholder’s activist resolution with its proxy materials for a shareholder vote.   With its passage, the proposal requires Ruger to prepare a report.  That’s it.  A report.  What the proposal does not do . . . and cannot do . . . is force us to change our business, which is lawful and constitutionally protected.  What it does not do . . . and cannot do . . . is force us to adopt misguided principles created by groups who do not own guns, know nothing about our business, and frankly would rather see us out of business. 

As our CEO explained, “we are Americans who work together to produce rugged, reliable, innovative and affordable firearms for responsible citizens.  We are staunch supporters of the Second Amendment not because we make firearms, but because we cherish the rights conferred by it.  We understand the importance of those rights and, as importantly, recognize that allowing our constitutionally protected freedoms to be eroded for the sake of political expediency is the wrong approach for our Company, for our industry, for our customers, and for our country.  We are arms makers for responsible citizens and I want to assure our long-term shareholders and loyal customers that we have no intention of changing that.”
Change their business?  What's going on here?  Where did this come from?

According to the Seattle Times, Ruger (a publicly traded company) has been targeted by gun control forces, specifically Catholic nuns who are trying to make them adopt policies that are bad for the company.    
Last week, Sister Judy, who lives in a convent in Seattle’s Wedgwood neighborhood, helped orchestrate what is believed to be the first activist-led shareholder revolt at an American gun manufacturer.

The size of the nuns’ win appeared to startle the gun industry. It also came as a welcome shock to the gun-control movement, which was long accustomed to being ignored by the big businesses at the center of the gun debate.

“This is our biggest win, by far, in 20 years of pushing corporations for social change,” Byron said Tuesday. “When they announced it, I couldn’t believe it. I about fell out of my chair.”
Unlike conventional investors, the nuns buy stock specifically so they can go to stockholder meetings and propose gun control initiatives.  Rather than investing in a company for its growth potential, the nuns invest in it to try to make it do things in compliance with their view of social justice. 
Out of a small office in the Roosevelt neighborhood, Byron has for two decades run a campaign to get corporations to include “good works” in their profit-making. It’s called the Northwest Coalition for Responsible Investment. The strategy is to first buy stock and then request an audience with corporate boards or CEOs. If that doesn’t work, the nuns take it up a notch by petitioning directly to the company’s owners — the shareholders.

These resolutions almost always lose. In the past three years, of 56 corporate resolutions filed by the group, only one was approved by a vote of the shareholders (in 2017, when Exxon’s shareholders agreed to force the company to report on how climate change will affect its long-term business.)

Sturm Ruger ignored the nuns’ request for a meeting. Big mistake: As anyone who has ever been to a Catholic fundraising breakfast can attest, nuns can be very persistent.

By then the nuns owned the minimum amount of stock ($2,000 worth) required to file a formal resolution. The one for Sturm Ruger called on the company to track incidents of violence involving its firearms; to reveal what it’s doing to make guns safer, including research on “smart gun” technology; and to report on the risks that gun violence poses to the company’s reputation and finances.
As always, the gun grabbers don't know what they're talking about.  They're laboring under the bad conception that gun sellers are unregulated, not that they're regulated every step of the way from the factory receiving raw materials until a buyer at a gun store undergoes background checks and fills out a Federal form before getting their gun.  They completely miss the fact that the vast majority of guns used in crimes are stolen and whether Ruger's products are used in a crime or not as nothing to do with Ruger.

As I'm sure you'd guess, the nuns say “We’re not trying to get rid of guns,” they're just trying to improve gun safety.

The Seattle Times is clearly in favor of what the nuns are doing, and I expect that.  More troubling to me is that they imply the investment company BlackRock is with the nuns.  I went to their link to a statement by BlackRock and they say they are not shareholders of any gun company.
There are three publicly traded companies in the US whose primary business is firearms manufacturing: American Outdoor Brands, Vista Outdoor and Sturm, Ruger. BlackRock holds none of these firearms manufacturers in our active equity portfolios (where stocks are selected by our portfolio managers within guidelines agreed to by clients). In BlackRock’s index equity products (where stocks are determined by third-party index providers) – these three companies represent 0.01% of total assets.
The distinction is fine, but they're not shareholders, they have invested in index funds from other companies that hold stock in those companies.  The other companies hold stock in the gun companies.  That's the referenced 0.01% of the company assets.  BlackRock is the world's largest asset manager with $6.3 trillion in assets under management as of July 2017.  That 0.01% is still $630 Million. 

Exact details of what BlackRock has discussed with Ruger and the others are confidential, however in that linked piece, they mention the kinds of things they ask the companies and it implies they don't know enough about what they're investing in.  To excerpt the two that seem the worst:
  • How do you determine where you will allow your products to be distributed? (Do your distribution channels include private sales? Do you require distributors to disclose to you warnings received by the Bureau of Alcohol, Tobacco, Firearms & Explosives? Do you monitor whether distributors and retailers of your products have a high volume of their guns identified as having been used in crimes?)
  • What strategies do you employ to monitor how your products are being sold? (Do you require retailers to certify that they do background checks? Do you require training of retailer staffs? Do you have a process in place to flag orders of unusual size or identify patterns of disproportionate sales?)
Do those sound like questions from someone who understands firearm sales to you?  Where do they find retailers who don't require background checks?  A company the size of Ruger sells most of their inventory to wholesalers - distributors - who sell to retailers.  Do they think these companies don't follow federal laws?  I don't expect everyone at BlackRock to be familiar with these laws, but I do expect anyone buying into these companies to learn about their business, and I especially expect anyone who wants to lecture the industry to know more than I see here.  Should BlackRock investors demand they get educated? 

The decision to be a publicly traded company vs. privately held is a big decision.  It brings opportunities for raising money for expansion.  That your company can be taken over by a big enough stock buyer, and driven into the ground is a drawback that plays out in many mergers and acquisitions.

(Sister Judy Byron - Seattle Times photo)

Thursday, May 17, 2018

It's Kind of Sad

It's kinda sad watching Slidefire sink into the sunset.  Like many of you (I assume) I've been getting their "going out of business sale" emails for the last few weeks.  It seems I've been getting their ads every other day (? I think) for a few weeks and it has just been a continuing dribble of sad news.

I don't own a bump-stock.  Never wanted one.  Never cared about them.  I'm just sad to see a small business killed by the stupidity that flared into existence over banning bump stocks.  One crime in the history of the world has used a bump-stock and because of that we need to ban them and drive some entrepreneur's dream into the dirt.  Slidefire is not responsible.  Neither the owner, the company nor the devices are responsible.  Only the moron pulling the trigger is responsible.  

Bump-stocks were, if you're unaware, outlawed in the Florida RINO Gun Control Act of 2018, passed within days of the Stoneman Douglas High School shooting.   Which also didn't involve a bump stock.

At the very top of the web site, it says:

ALL SALES FINAL – On Sunday, May 20, 2018 at midnight CDT, Slide Fire will cease taking orders for its products and shut down its website.  Orders placed prior to May 20th, 2018 will all be processed and shipped.  We thank you for your support.
Everybody thinks bump-stocks on ARs or AKs.  They also make a nifty little kit for "America's littler rifle", the Ruger 10/22.  

Here's wishing them luck in whatever direction they choose.

Wednesday, May 16, 2018

Hacking Alexa, Siri and Google Assistant With Hidden Voice Commands

A lot of people have written about how getting one of these voice-activated digital assistants is voluntarily bugging yourself.  The reactions have widely varied, but for the software to recognize when you call it, ("OK, Google"...) it has to be listening at all times.  It's a deliberate design feature, or decision.  Most people who read here, at least, would be aware that they were installing a full time listening device in their homes.  To some, they assume it's an invasion of privacy and don't want these things; to others, it's something they ignore for the perceived benefits of the digital assistant.

The New York Times tech blog reports that a group of researchers in a couple of institutions have been able to secretly activate the systems on smartphones and smart speakers, simply by playing music with sub-audible (to humans) sounds hidden in it over the radio.
A group of students from University of California, Berkeley, and Georgetown University showed in 2016 that they could hide commands in white noise played over loudspeakers and through YouTube videos to get smart devices to turn on airplane mode or open a website.

This month, some of those Berkeley researchers published a research paper that went further, saying they could embed commands directly into recordings of music or spoken text. So while a human listener hears someone talking or an orchestra playing, Amazon’s Echo speaker might hear an instruction to add something to your shopping list.

“We wanted to see if we could make it even more stealthy,” said Nicholas Carlini, a fifth-year Ph.D. student in computer security at U.C. Berkeley and one of the paper’s authors.
In a way, this isn't much of a surprise, right?  They're taking advantage of the "always-on, always listening" nature and trying to see just what the algorithms can extract from the other sounds.  I'd think the designers would do this.  Further, hijacking these things is nothing new.  Remember when Burger King grabbed headlines with an online ad that asked ‘O.K., Google, what is the Whopper burger?”  It caused Android devices with voice-enabled search to read the Whopper’s Wikipedia page aloud.  The ad was canceled after viewers started editing the Wikipedia page to make it more ... let's say comical.  Not long after that, South Park followed up with an entire episode built around voice commands that caused viewers’ voice-recognition assistants to spew adolescent obscenities.

A research firm has said that devices like Alexa, Siri and Google Assistant will outnumber humans by 2021, and add that more than half of American homes will have a smart speaker by then, just three years away. 

These security researchers aren't leaving bad enough alone. 
Last year, researchers at Princeton University and China’s Zhejiang University demonstrated that voice-recognition systems could be activated by using frequencies inaudible to the human ear. The attack first muted the phone so the owner wouldn’t hear the system’s responses, either.

The technique, which the Chinese researchers called DolphinAttack, can instruct smart devices to visit malicious websites, initiate phone calls, take a picture or send text messages. While DolphinAttack has its limitations — the transmitter must be close to the receiving device — experts warned that more powerful ultrasonic systems were possible.

That warning was borne out in April, when researchers at the University of Illinois at Urbana-Champaign demonstrated ultrasound attacks from 25 feet away. While the commands couldn’t penetrate walls, they could control smart devices through open windows from outside a building.

This year, another group of Chinese and American researchers from China’s Academy of Sciences and other institutions, demonstrated they could control voice-activated devices with commands embedded in songs that can be broadcast over the radio or played on services like YouTube.
Security researchers have a habit of saying that releasing information like this isn't bad because they think the bad guys have either thought of it already, or they would think of it on their own.  Maybe, although some times just knowing something is possible can keep the experimenter going during the inevitable times when things just don't seem to be working.  The article does say these exploits haven't been found "in the wild", but as more people become aware of the possibility, I'd expect them to start showing up.

Hopefully, the research being revealed will get the companies selling this software to try to get ahead and make their devices more robust.  My version: I have an older iPhone (6s) with Siri.  It's possible to configure the phone to listen all the time, so that when you say, "Hey, Siri" it answers.  I have that turned off, and have read Siri does not actually send data back when it's disabled.

I'm going to close with one of the last paragraphs in the article, because it contains the very best phrase in the whole piece. 
“Companies have to ensure user-friendliness of their devices, because that’s their major selling point,” said Tavish Vaidya, a researcher at Georgetown. He wrote one of the first papers on audio attacks, which he titled “Cocaine Noodles” because devices interpreted the phrase “cocaine noodles” as “O.K., Google.”
For some reason, it reminds me of this meme:

Tuesday, May 15, 2018

Inside the Worst Maritime Disaster in Decades

Any recreational boaters here?  Anyone who has been out of sight of land, where you know that if things go squirrely you don't go home?  Known that the bottom was a mile or more below you and that was closest land you could get to?  Without your boat you're in a world of trouble.  If you're waiting for a search and rescue aircraft, you're a tiny target in a big ocean.  

I've always thought that the giant cargo container freighters, giant oil tankers, and other vessels in the size class near that of an aircraft carrier are capable of surviving anything the sea could hand out.  All of these are monstrous compared to sizes of boats I've been out on.  I've heard of guys on small sailboats surviving hurricanes.  Boats that people who work for a living and decide to get away for a few years, or retire onto, buy.  If a 40 or 50 foot, single-mast sailboat can take on a hurricane, why not a 790 foot long cargo ship capable of carrying 15,000 tons? 

Last month, Vanity Fair (of all places) ran an article on the wreck and sinking of the cargo ship "El Faro", a cargo ship that sailed right into the path of Hurricane Joaquin in 2015.  I remembered this because it was early October, and storms in that general area are always worth keeping an eye on.  I heard about this ship that had sailed and was heading for trouble, but assumed that with a professional captain on a ship that size, they shouldn't be at terrible risk.  So they get inconvenienced by changing course to stay in a lee or "heave-to", slow down, and point the bow into the wind, so what?  They should make it to their destination.

The article is long, but worth reading.  I don't think I'm giving away a major spoiler that the problem was a convergence of the storm intensifying more than expected, and the captain not willing to give it the respect it deserved, worrying too much about making his schedule.  Compounded with bad and conflicting information about the storm, because the forecasts were made by people.  Despite the elegant computer models and supercomputers to run them, no two models agree exactly: an experienced forecaster is still the best judge.  As the old saying goes, experience is gained by making mistakes and, most importantly, learning from them. 
It is unlikely that Davidson ever fully understood that he had sailed into the eye wall of Joaquin, but he must have realized by now that he had come much too close. As is usually the case, the catastrophe was unfolding because of a combination of factors that had aligned, which included: Davidson’s caution with the home office; his decision to take a straight-line course; the subtle pressures to stick to the schedule; the systematic failure of the forecasts; the persuasiveness of the B.V.S. graphics; the lack of a functioning anemometer; the failure by some to challenge Davidson’s thinking more vigorously; the initial attribution of the ship’s list entirely to the winds; and finally a certain mental inertia that had overcome all of them. This is the stuff of tragedy that can never be completely explained.
Davidson is Captain Michael Davidson; experienced, 53, and known as a stickler for safety.  He left behind a wife and two college-age daughters. Neither his remains nor those of his shipmates were ever recovered.  As best as can be reconstructed, El Faro went down around 7:40 AM on the morning of October 1st.  Search operations were actually started by Hurricane Hunters later that day, but not beginning in earnest until the next day due to the hurricane.  No survivors were ever found.  The ship was eventually found in 15,000 feet of water, and recovery operations attempting to find the onboard voice recorder lasted until April of 2016.  Coast Guard investigators placed virtually all of the blame on captain Michael Davidson.

GOES-13 Image (from Wikipedia) that's coincidentally captured as El Faro was sinking.

Monday, May 14, 2018

How a “location API” allows cops to figure out where we all are in real-time

That's the provocative title of a piece that was on ARS Technica over the weekend - and they include a really novel link.  You can try to see if your phone, or a handful of other things, can be located.  Think of it as a way to test your privacy measures, your VPN or browser security.
The digital privacy world was rocked late Thursday evening when The New York Times reported on Securus, a prison telecom company that has a service enabling law enforcement officers to locate most American cell phones within seconds. The company does this via a basic Web interface leveraging a location API—creating a way to effectively access a massive real-time database of cell-site records.
The API - Applications Program Interface - is the key.  It's what appears to be Securus' contribution to the tracking.  The API makes it possible for any programmer to write applications that use this data.  The data itself is not from Securus.  They rely on data brokers and location aggregators that obtain that information directly from mobile providers.
The Texas-based Securus reportedly gets its data from 3CInteractive, which in turn buys data from LocationSmart. Ars reached 3CInteractive's general counsel, Scott Elk, who referred us to a spokesperson. The spokesperson did not immediately respond to our query. But currently, anyone can get a sense of the power of a location API by trying out a demo from LocationSmart itself.
If you want to see where the fight over the end of the Fourth Amendment is currently taking place, this may not be it exactly, but I bet you can see it from here.
Securus’ location service as used by law enforcement is also currently being scrutinized. The service is at the heart of an ongoing federal prosecution of a former Missouri sheriff’s deputy who allegedly used it at least 11 times against a judge and other law enforcement officers.
"To access this private data, correctional officers simply visit Securus’ Web portal, enter any US wireless phone number, and then upload a document purporting to be an official document giving permission to obtain real-time location data," Wyden wrote.
The reason the data is available is because cell phones need to "talk" with the towers and the towers triangulate on a given number to aid in handling the call.  If several towers receive the handset, as is usually the case, they can tell by signal strength changes the likely direction the phone is moving, so that they can hand off to the next cell more easily.  

With the Securus system, the phone's location isn't obtained from the phone's GPS; the provider's  knowing the location has nothing to do with a phone being a Smart phone or a dumb old flip phone, and it has nothing to do with turning "location services" off.  The location awareness comes simply from being a phone on the cellular network.

Similarly, while the location provided by triangulating between cell towers is low resolution - they might know that the phone is somewhere in a quarter or half mile diameter circle - this was adequate for a lot of criminal prosecutions.  If someone's argument was "I wasn't even there", and the phone records verified they weren't within that quarter mile circle but in another cell some distance away, the story checked.  GPS enhances that measurement.  You can envision someone being falsely accused of something by a third party but being in the same cell as the third party.  Perhaps they're within a few hundred yards of the accuser; two or three houses or apartments away.  They're really "not even there", but the location being accurate only to within a quarter or half mile circle is incapable of proving or disproving that. 

The LocationSmart test page.  I haven't decided if I really want to run the test.  With a service like this, I want to read the "Terms of Use" and they don't really make me comfortable.  I'd like them to say, "this is a one-time demo; we're going to destroy the number you gave us in 24 hours along with all the information you entered".  Nope.  In one place it says, "You agree to provide LocationSmart with true, accurate, current, and complete information about yourself (the "User Information") if requested, and maintain and update such information to keep it true, accurate, current, and complete at all times."  I added that bold format.  That sounds like they're going to keep anything I tell them. 

In the old days, people used to wonder if the FBI had a file on them and we used to say the easiest way to get an FBI file started on you was to request a copy of your FBI file under the Freedom of Information Act.  I just can't help but wonder if checking to see if your phone (or browser, landline, and so on) can be tracked is a way to ensure that it gets tracked.  But then I tell myself it's already tracked anyway.

Sunday, May 13, 2018

Mother's Day 2018

Mothers's Day started early for me.  I started tonight's dinner, a smoked beef brisket, last night right before midnight.  My smoking equipment allows me to get about 6 hours out of a load of wood chips, but the chips tend to not fall down into the zone where they smoke, and by two hours into the burn, they need to be given a bit of a shove (I use a BFS - a big screwdriver).  As I usually do, I set a timer on my phone to wake me in two hours and went to bed.  Got up at 2AM, took a quick inspection, poked down the chips, set the time again, and went back to bed.  I basically got up a 2, 4, 6 and 8 AM (a few minutes later every time).  It went about as well as these overnight cooks go, and I got a decent amount/quality of sleep. 

The brisket reached its desired internal temperature by just before 1:30 this afternoon, and we quickly wrapped it in parchment cooking paper and stuck it in a cooler to let it rest for a while. 

Nice bark, but no pink smoke ring (a known drawback to these electric smokers), and a bit too dried out.  This is just the flat of a brisket; a higher quality brisket to cook is what's called a packer brisket, which has the flat and a higher-fat portion called the point.  The thinner sections of brisket, near the camera, were more dry than sections cut better across the grain farther to the right.  The thicker portion of the brisket came out more moist.  Slices the width of a typical #2 pencil should not break when supported by their middle, and they don't.  Grading myself, I'd give it a C. 

As I've mentioned before, with the kids living out of town and both of us now the oldest parents in the family, it tends to be low key here on holidays. 

We're in for an unusual week here, at least for May.  80% chance of rain tonight and tomorrow, and it stays above 50% through next Friday.  Good time for cutting some metal. 

Saturday, May 12, 2018

Redesigning the CNC Mill Enclosure

When I finished converting my milling machine to CNC, I moved onto building an enclosure for it. More details here.  Briefly, the enclosure always struck me as an afterthought on an otherwise very worthwhile DVD of plans I bought.  The creator, Daniel Kemp, better known as Hoss, did good drafting quality drawings for all of the parts involved in the conversion, but the construction of the enclosure was in a handful of videos on his YouTube channel and the materials needed were found on his dedicated forum at CNCZone.   The only drawing was for the plywood chip tray that the mill sits in.  I've run this picture before, but this is the enclosure when I finished it. 
As the system has aged, a couple of issues have surfaced that have gotten to the point that I need to change the front over to something else.  The biggest annoyance is that the doors are just too short, and I scrape my head on the top rail far too often.  The doors slide on a screw captured in the track on top, folding in at their middle - they're bifold doors - and so I can't put some foam or something on the middle of it so I don't scrape myself.  (The track is also source of another annoyance - the doors come off the captive screws and fall into the enclosure, suspended by just the hinges at the end panels.)

After a lot of research, I'm going to completely redesign the front.  I'm going to three doors, with the middle door sliding to the side to access the center of the mill where most work needs to be done.  I'll put the middle door in one sliding track so that it can slide to either side, and there will be two doors on another track, so that they can slide to the left or right and allow access to the corresponding end of the table.  It's going to look more like this:
The doors will still be clear Lexan; the smokey, almost purple color here is an artifact of the rendering in Rhino3D V5.  The frame is sitting on the front board of the chip tray in this rendering; the new pieces will all be wood, 1x2s, and mounted to the aluminum extrusion top and bottom.   

Most importantly, the doors will be 33 inches tall instead of 25.  That should keep me from hitting my head.  Right now the top rail is the same distance above the floor as my upper lip.  The extra 8" ought to eliminate that problem.  If the Lexan I can find is 36", I'll make the doors .36"

I'll need to work this into the shop at some point, where I'm working on the fire eater engine.  This week's work has all been on the big lathe, but there's a little work to be done on the milling machine before I interrupt everything. 

Friday, May 11, 2018

New Frontiers in "There's Never A Shortage of Things to Fix"

I don't know about the rest of you, but there's always something around here that needs to be fixed.  Most of the time it's something I've never tried to fix before and frequently something with no electronics content - what I consider my "home field advantage".

This week ended up being broken vacuum cleaner week.  I've never had one broken vacuum cleaner to fix in my life; this week I had two.  As it turned out, they were both electrical problems, which helped.

The first one was the carpet attachment for our house cleaner.  It's not this model Panasonic, but the same basic concept: there's a canister with the dust bag, power on/off switch and a connector for the hose to plug into.  The hose has wires embedded in it that brings the power to carpet attachment.

On Sunday, Mrs. Graybeard got the thing out to clean our couple of throw rugs and the carpet attachment wouldn't turn on.  Before going too far into the whole assembly, she opened up the carpet attachment and verified that the belt was good.  I eventually came over and volunteered to dive in.  We verified that everything in the beater was wired up and motor seemed good, so now we're down to the main vacuum or the hose.  We quickly isolated it to the wires that run down the hose, and eventually bring power into the carpet beater.  There are two wires, one was open from end to end. 

It took more time to take it apart because there are single piece molded plastic parts on both ends.  On the vacuum cleaner end, there's a rotary joint, so the hose can spin around.  On the handle end, it just ends in the handle, which has a switch.  A wire had pulled out of its connector in the end of the hose nearest the handle.  Aside from a piece of duct tape to hold together a rubbery plastic elbow that I cut open to inspect the wires (visible in the picture at the top of the hose, going into the connector on the body), it's just as it was before the wire pulled out. 

Once that was fixed, on Wednesday I went to turn on my Shop-Vac to clean up some chips and residue on the lathe (where I'm working on the cylinder for my flame eater engine).  The Shop-Vac didn't turn on - I had used it the day before.  Putting an ohmmeter across the AC plug, I could see the motor never got connected.  Now it's down to the motor, the power switch or the power cord.  I started looking for a circuit breaker or fuse or something.  Nothing found.

After some research online and YouTube, I found that the motors in Shop-Vacs have some sort of fuse attached to the motor with a molded plastic holder.  With a couple of videos watched, I went and tore down the vacuum until I could hold the motor in my hand.  Sure enough, the fuse was open.  Only it's not a fuse.  After unsuccessfully trying to find one for this specific model Shop-Vac , I found that the thing is built in an amazingly crude manner.  See that little yellow square? 

This is a pic from online, not from mine, but it looks exactly like mine.  The orange wire goes to the power switch and the copper wire goes to a stator on the motor.  Inside the yellow plastic piece, it has two sorta V-or U-shaped spring clips that you shove the flat terminals under (these are crimped onto the orange and copper leads) and these clips ride on what looks like a short piece of wire.  Only it's not wire, it's solder.  That's right: when the motor draws too much current, the solder melts and disconnects the power.  Looking at the terminals in mine, it's hard to see how it could not work, since only about an eighth inch (or less) of solder wire looks like something other than pristine wire.

I spent my entire career in high reliability electronics and I know that influences my thinking, but when I understood what they were doing, I was appalled.  Think of the numbers of Shop Vacs that get thrown out because a little piece of solder (fusible link) opened and there's really nothing substantially wrong with the motor.  For some reason, the motor drew too much current and blew the fuse.  If it was a real circuit breaker, maybe add a buck or two to the cost, you could just press a button and reset the fuse.  Maybe let it cool down, first.  Heck, letting it cool down overnight makes more sense than using a piece of solder and throwing it out when it opens. 

Better yet, a thermal fuse that opens if it overheats and then resets itself when it cools down enough. 

Shop-Vac has a warranty, and I read that if you had proof of purchase and contacted them, they'd send you a new motor.  Otherwise the motor cost what a whole new Shop-Vac costs.

I spent a lot of time agonizing over this, because I don't really have numbers on what the "fuse" needs to do.  I could put a piece of solder in there and call it a fuse.  I could put a piece of copper wire in and call it the fuse.  Maybe the solder is 20 ga. wire while the copper would be 30 ga,.  At some point either one will melt. Whether that's before or after the vacuum catches fire is something I can't answer.

I eventually just dialed up a bit of "you're over complicating things", found the thickest solder I have, wound a double strand of it (to approximate the original's size) and put the vacuum back together.  Works like a charm.  I used it a half dozen times today, a few seconds to maybe a minute at a time. 

Will it hold up?  Time will tell.