Aaron's blog

The Dark Forest by Liu Cixin

By aaron.axvig, Tue, 04/07/2020 - 17:44
Date completed
3 years 3 months ago

Very good read!  Plenty of great spaceship-type action, and grand plot strategies that reminded me of the style of the Foundation trilogy.  But also I really enjoyed the sequence where the main character dreams comprehensively about spending time with the perfect woman.

I think I am getting better at processing Chinese names as they were a little easier to remember in this second book of the trilogy.

Completion status

How I make coffee with the AeroPress

By aaron.axvig, Fri, 04/03/2020 - 07:55
AeroPress and other coffee making things

I was reading some discussion about the AeroPress recently and many people were describing their process.  There are some people who love their coffee in a very precise way!  My process is probably close to the ultimate in laziness (80% of the quality for 20% of the effort).

I use a vacuum mug that is probably 16 oz. capacity.  Over time I have become able to eyeball how much water in the electric kettle will result in the mug being almost full.  So I fill the kettle to a little over the top of the "0.5L" text and start it.  While it heats, I put the filter and grounds (a couple heaping teaspoons of cheap stuff) into the AeroPress.    As the kettle heats up it starts making noise.  After about 10 seconds of noise it is the temperature that will result in an easily drinkable cup of coffee immediately after brewing.  So I take the water and poor it over the grounds, slowly at first so that all the grounds become wet and then rapidly so that they get mixed up more.  If I don't wet all the grounds then some of them tend to stay floating on the surface.

About 70% of the time I do some mixing with the paddle that comes with the AeroPress.  Coffee drips out the bottom and as the water level lowers I add more water, sometimes stirring more.  I let it drip and keep adding water until the kettle is empty.  Then it is time to press; I go all the way to the bottom and squeeze the last bit out of the grounds.  I'm not sure if that is recommended!  If I overfilled the kettle a little this is when I will find out, as coffee dribbles over the edge of the mug.  Then I pop the puck of grounds into the trash, rinse everything, and wipe it down with a paper towel.

Some places where I am probably losing quality:

  • In that discussion many people rinse the filter to avoid a paper taste; I don't do that.
  • It is very common guidance for any brewing method that the water should be heated to just under boiling.  My water is significantly cooler than that.
  • Many people optimize some sort of blooming process; I just go for the full immersion of the grounds right away.
  • I squeeze the juice out of the grounds into the coffee cup and I'm not sure that is a good idea.


Filename issues when moving from Dropbox to SharePoint

By aaron.axvig, Tue, 03/31/2020 - 16:47

I was recently helping someone with a transition from Dropbox to SharePoint/Teams/OneDrive for Business.  They were running into issues with filenames.  As an all-Mac business there were many files they had created with colons in the file or folder name.  Windows doesn't allow those characters and SharePoint does not appreciate them either.

Some Googling suggested that downloading a ZIP of the Dropbox folder might solve the problem.  I found that when I extracted the ZIP the offending files were just missing.

I ended up creating a droplet on Digital Ocean and syncing the Dropbox folder to it.  Even though it was 20GB and 14,000 files, the sync only took three or four minutes!

Then I set about carefully renaming things.  Thanks to StackOverflow I mainly worked with variations of this command: find . -type f -name "*:*" -exec rename -n 's/:/-/g' {} + It renames all files that contain a colon by replacing that with a dash.  If you have directories that contain a colon then it will fail to rename those.  Run again with -type d to rename those.  Remove the -n to actually make the changes; with -n it just tells you what it would do.  Append | wc -l on the end if you want to count how many issues you have.

Towards the end I was just using find . -name "*:*" to do final checks.  And I checked all the invalid characters.  Some of them require \ as an escape character; for example find . -name "*\?*"

Then you may find out other odd things.  For example, file and folder names cannot start with a space.  find . -type f -name " *" -exec rename -n 's/\/ /\//' {} + can help with that.

For the actual sync I setup Dropbox and OneDrive for Business on the same machine (enable long file names).  Then I used robocopy /MIR to copy files into the OneDrive folder.  After my first run of that, OneDrive started syncing as expected.  Then it got upset about some filenames, which is when I realized that there are additional characters not allowed in SharePoint that are OK in Windows.  It offered to fix those, replacing the characters with an underscore.  Then I found out about the spaces issue and fixed that back on the Linux droplet.  After Dropbox synced I ran robocopy /MIR again to put in those new fixes.  A significant problem with this method is that OneDrive for Business changes the filesize on some Microsoft filetypes so if you have a large amount of those types of files it might cause difficulties.  After the initial robocopy the magnitude of this issue can be quite reduced by using the /MAXAGE parameter to limit the files that it copies to the last few days.


Trivia via VHF

By aaron.axvig, Fri, 03/20/2020 - 20:15
Our VHF radio

For entertainment tonight we played trivia via the VHF radio. There were about 15 teams playing.

The host read four questions for each round on the radio and we submitted our responses for each of the five rounds in a Google Docs form. At 5 points per question and a bonus point for signing up early we were in the middle of the pack with 31 points going into the final question. We wagered two points!

The final question asked who performed the song that was played at the beginning of the cruisers net this morning.  The cruisers net is also a VHF affair which consists of announcements, comings and goings, buy/sell/trade, and requests for help.  The host typically plays snippet of a song at the beginning of the program.  Of course no one knew that it would be a question in trivia that night, and based on the scores we heard I don't think anyone got it right.  It was '39 by Queen.  Pretty interesting that Queen wrote a folk song like that.  Betting only two points paid off and we tied with one group for third place!

In other business, everything except essential services was shut down yesterday in the Bahamas. It turns out most things that we care about ARE essential services...groceries, gas, water, laundry, and shipping parts (our steering needs some maintenance). And restaurants are doing take-out if we really want some fried food. No big social events is one of the few significant changes for us. And our friend Daniel is not coming to visit for a week as planned (it is interesting that he technically could, but it would be unwise).

We still plan to be in Georgetown until well into April, but that could easily change. Ideally tourism would be encouraged again by then and we would see a few more places on the way back to the US sometime in May. If we want to go back to the US anytime, we are able to, and stopping at Bahamas islands along the way for essential services is OK too.


The Rothschilds: A Family Portrait by Frederic Morton

By aaron.axvig, Wed, 03/18/2020 - 13:39
Date completed
3 years 4 months ago

Fairly interesting book about the Rothschilds family.  I'm writing this up maybe six months after I stopped reading it, and I made it about 2/3 of the way through.  I guess now I know that there was a father and five sons, they were into banking, had a lot of nice houses/castles, etc.  To many names to remember though!

Completion status

Seawater Pro watermaker install on our Hunter 376 sailboat

By aaron.axvig, Mon, 03/09/2020 - 09:33
Watermaker system overview

In this post I will document the Seawater Pro watermaker that we installed one year ago.  It currently makes 15 gallons per hour here in the Bahamas at about 850 PSI membrane pressure while consuming about 850 watts.

I ordered and installed the system in March 2019, probably total installed cost was about $3,100 and a solid week+ of learning, working and running to hardware stores.

  • $2,575 to Seawater Pro.  It looks like this $2395 item currently in their store is basically what I got.  I would really recommend getting the "remote control" version which is basically a pretty panel to put the controls and gauges in, but it is $400 more and you have to draw the line somewhere.
    • Base system price was $1,595
    • $699 for the DC motor and brass pump upgrade
    • $39 for the SW30-2540 membrane (an upgrade? I see they retail for more like $200 online?)
    • $80 shipping and some tax were the remainder
  • Additional costs rough estimates (one year ago by memory!)
    • $250 for plumbing odds and ends not included "in the box"
      • Boost pump is far from high pressure pump
      • Had to split air conditioner sea water intake (do not run AC and watermaker at the same time)
      • New dump overboard through the hull for salt water output
      • New input into top of water tank
      • Valves to direct product water overboard or into water tank
      • Misc. to get house water to the system for flushing
    • $250 for wiring
      • About 30 feet of 2AWG marine wire
      • Circuit breakers
      • Compression lugs, heat shrink, looming, etc.

What the operating process looks like, plus notes about a few steps that we skip:

  1. Ensure needle valve is open (unrestricted).
  2. Ensure product water valves are set to flow overboard and put that dump hose out the v-berth hatch. (usually skip this and just dump straight into water tank...20 seconds of 2,000 TDS water is quickly diluted by the following hour or two of usually 100 TDS water)
  3. Turn on salt water boost pump.
  4. Verify that the pressure gauge before the salt water high pressure pump shows higher than 0 PSI (usually skip this, depends on cleanliness of sea water in the area).
  5. Turn on salt water high pressure pump.
  6. Tighten needle valve over about 20 seconds to bring pressure to 750-850 PSI, observing GPH meter rise to 15 GPH (or more, or less).
  7. Turn on the TDS monitor and observe it drop from around 2,000 to under 200.
  8. Open product water valve to water tank, and then close the one that dumps overboard. (usually skip this)
  9. Put away overboard dump hose. (usually we don't dump any water so skip this)
  10. Run for a long time, typically one to two hours.  Monitor both low pressure and high pressure gauges every 20-30 minutes, and also listen to the sounds of the system for interesting changes.
  11. Loosen the needle valve slowly over 20 seconds to bring high pressure to 0 PSI.
  12. Turn off high pressure pump.
  13. Turn off boost pump.
  14. Flush system with fresh water. This ideally would mean doing something with the garden sprinkler timer but I haven't gotten that to work so I flip open a valve under the settee. (usually we skip this)

So basically we are doing two "naughty" things.  We don't dump the initial product water overboard, but the math on dilution is quite convincing to me that it doesn't really matter, the water tastes fine, and we are generally healthy.  And we don't flush with fresh water after running, but the system performance does not seem significantly degraded.  Perhaps we will need to replace the $200(?) membrane earlier than the 5-10 years that people normally get out of them.

Our system has a 12V high pressure motor.  At operating pressure this alone seems to draw about 800 watts (65A at 12V), with the boost pump drawing the other 50 watts.  For our 4x 100Ah 12V lithium iron phosphate (BattleBorn) battery bank this is no problem.  It may not work so well on smallish lead-acid battery banks, in which case using a generator and 120V AC pump would be wiser.  If we run the generator our battery charger can put out about 90A so it can charge the battery a little in addition to keeping up with the watermaker draw.  But mostly we get enough solar from our 1100 watts of panels to keep up with the fairly liberal demands of the two of us.

Boat water systems diagram
The complete water system diagram on our boat.  The watermaker is half of it!
New input into water tank
The new fixture that I added on top of the water tank for product water to drop in.
Boost pump breaker
The breaker for the salt water boost pump.  Turn this on first!
Seawater plumbing under the floorboards
Under the floorboards with dog hair!  The seacock has the yellow handle on it, which flows to the strainer on the left.  Above that, a Y-valve goes to both the 120V AC pump for the air conditioner (top) and the 12V pump which boosts seawater to the watermaker's high pressure pump.  The "Watermaker Supply" breaker on the boat's breaker panel turns this 12V pump on.  Someday when I need to pickle the system I will have to modify this plumbing to provide a way to suck the pickling solution into the system.
Breaker under nav station
This breaker is under the nav station, like exactly where it could be bumped by a knee.  I think the labels explain enough for this picture!
Pump nameplate
Here is the nameplate on the high pressure pump motor.
Main watermaker parts overview
This is an overview of all the main watermaker parts on a shelf that I built in the v-berth closet.  If the photo was oriented correctly, from left to right: TDS and GPH gauges, coiled up hose for dumping product water out the v-berth hatch, high pressure pump, needle valve (silver handle), high pressure gauge peeking out under the shelf, fresh water flush timer and one-way valves, and sea water filtration.  The glowing thing in the back is daylight coming in through the through hull.
Seawater filtration
Seawater filtration!  Seawater leaves the boost pump and travels under the couch around the table, under the v-berth sink, through the space where the water tank is, and finally comes in through the left one-way valve.  Fresh water for flushing leaves the house pressure pump (I installed the carbon filter that came with the system so that it filters all house water...to remove any chlorine which would damage the membrane) and travels under the v-berth sink, through the space where the water tank is, and finally comes in through the timer and right one-way valve.  Then ideally a 20 micron filter and 5 micron filter.  I believe Seawater Pro says that the actual sizes don't matter much.  I just run 20 micron filters in both.  In dirty water they plug up pretty fast (3-5 hours?) so I have been known to just run one out of frustration...lasts longer then.  Not optimal for system life I guess.  In the Bahamas we have run with both for maybe 30 hours now and they are still quite clean.  I guess I didn't need the 20 filters that I stashed under the bed!  When the pressure on this gauge drops to zero it means the boost pump isn't able to pump enough water through the filters because they are dirty, so soon your high pressure pump will start making upset noises as it draws in air or a vacuum.  Not good for that, should be avoided.
High pressure pump close-up
A closeup of the high pressure components.  The high pressure pump has to be oriented with the yellow fill cap/dipstick facing up.  The pump can be rotated to any 90-degree position on the motor so if you need to bolt the motor to the wall that is fine.  Mine is bolted to the shelf, which is built out of PVC boards from Lowe's/Home Depot.  The big high pressure line coming out of the pump runs to the far end of the membrane housing which is under the v-berth bed.  And then you can see the "near" end of the membrane enclosure in this photo.  It has two connections.  The first is high pressure to the gauge you see here, this is what we run at 750-850 PSI.  Then the needle valve which lets some water past but still holds the pressure high.  Then that pipe (which mysteriously became dirty after a few hours of running) goes overboard through the hull in the back of the cabinet.  My positioning of these things is not ideal and I can't quite tighten one of the connections enough and still have them fit it the "custom" hole I made in the shelf, so I get a very flow drip in this part of the high pressure system.  The second connection is the product water output.
Plumbing for directing product water
This is the plumbing for handling the product water.  First it hits the sensor for the TDS monitor and then goes to the GPH meter.  From there I can choose to direct the water to a hose that I can put overboard out the v-berth hatch, or send it to the water tank.  A Y-valve would be ideal for this but I couldn't find the appropriate one in-stock at the time.

That's it!


The Three-Body Problem by Liu Cixin

By aaron.axvig, Sat, 03/07/2020 - 13:24
Date completed
3 years 4 months ago

Overall good.  I read reviews for the sequel and some of them said that reading this is a necessary slog and the sequel is the big payoff.  One of the best sci-fi books of all time I guess.  I do plan to read it.

This itself is still a good book though.  I found it hard to keep track of the characters, I think because they all have Chinese names.  Maybe I don't have anything to visualize for names that I am unfamiliar with, or maybe my brain just isn't wired to track those "words" as characters.  Otherwise the Chinese setting and cultural influences are interesting.

I actually should reread the book as I read a lot of it while falling asleep.  Might help rewire my brain for the names too!

Completion status

The Stone Sky by N. K. Jemisin

By aaron.axvig, Tue, 02/25/2020 - 18:05
Date completed
3 years 5 months ago

Much more going on in this third book, which I really liked.  More big events and especially more explanations of the history of the world.

It reminds me of a college class where the lectures were pretty boring but then one day the lecture involved some real-world uses for the stuff we were studying (how some industrial plants use huge inductors to fix their power factor and decrease their electricity bill).  I told the professor that I really enjoyed the lecture that day, which he probably already knew because I wasn't nodding off in the back of class...shame.  And he responded that you have to lay a little theoretical foundation so that you can understand the exciting real-world stuff.  I see a similar parallel here where the first two books were good enough but sometime frustrating, and this one was the big payoff.

After finishing the second book I read some news articles about the "puppies" factions attempting to influence the Hugo voting around the times that these three novels were coming out.  Definitely an unfortunate series of events!

I found myself questioning the wisdom of letting the Hugo winners list heavily influence my selection of reading...maybe populism isn't necessarily the best indicator of quality (to be clear, nothing against this trilogy in particular).  But on the flip side, I can remember having sympathized with criticisms of other awards (Oscars or similar?) that are selected by industry members, thinking that a group of insiders like that may not be very representative of my interests as a consumer.

Completion status

The Obelisk Gate by N. K. Jemisin

By aaron.axvig, Mon, 02/24/2020 - 09:34
Date completed
3 years 5 months ago

The second novel in this trilogy.  Overall a good read.  After the hint about the moon at the end of the first novel, I expected more to happen with that in this novel.  Instead it is just a build up (explanation) of the mechanisms that will presumably be used to manipulate the moon in the third novel.  And those mechanisms are so tediously explained, in such an "emotional" way that it is really a challenge for me to read.  Unbelievably, this second novel also ends with basically the same cliffhanger about the moon.

I say so much negative about these books, probably because I have such high expectations.  I chose to read them only because they were award winners.

Completion status

The Fifth Season by N.K. Jemisin

By aaron.axvig, Sat, 02/22/2020 - 11:09
Date completed
3 years 5 months ago

This was a pretty solid read, interesting story line and good world-building.  The writing style was not my favorite with so many paragraphs consisting of one short quip by the character and then a few sentences of the character's thoughts adding further context.  Sometimes it seemed like a really tedious way of revealing the "world" to the reader.

I started out thinking that the book probably won so many awards on a sort of "social justice" basis.  It seemed like a passably strong story, but I speculated internally that it might have been taken to award-worthiness by virtue of the strong female leads and non "white male" author.  These were unnecessary bitter thoughts and I left them behind as I got further into the book, please forgive me.  I still regard it as interesting that this book is different than so much (older, male-centric) sci-fi, containing homo, trans, and three-way relationships.  And the book is probably good enough to win awards without standing on a pedestal of social justice feel-goods.

Completion status