Tag: Memo to Self

Maybe next time I’ll get it right

Home Ec, Oddities, Science

Subaru Forester Gas Tank Capacity, Experimental Measurement Thereof

According to the manual, which I have hitherto had no reason to doubt, our non-turbo 2015 Subaru Forester has a 15.9 gallon fuel tank:

Subaru Forester - Fuel Capacity Chart
Subaru Forester – Fuel Capacity Chart

One screen shown on the dashboard’s Multi-Function Display gives the current mileage and estimated range:

Forester - MPG Range
Forester – MPG Range

Dividing those two numbers gives you 13.97 gallons, the current fuel level. As you’d expect, should the average miles per gallon change, the range will change accordingly.

The trip odometer says we have driven 72.8 miles since I filled the tank. Dividing that by the average mpg gives 2.3 gallons, so the tank could possibly hold 16.2 gallons, which, given all the averages involved, is reasonably close to the 15.9 gallons shown in the manual.

Being that type of guy, I have a spreadsheet tallying each fillup since the car was new:

  • 8.1 gal average
  • 7.5 gal median
  • 13.9 gal maximum

Long ago, my father taught me to fill the tank when the needle got halfway down and I’ve been doing so ever since. As a result, we have only rarely seen the Low Fuel Warning Light:

Subaru Forester - Low Fuel Warning Light info
Subaru Forester – Low Fuel Warning Light info

A concatenation of unavoidable events put us southbound on I-87 when that light went on. Given the estimated range of 70-ish miles, I planned to refuel at the New Baltimore Service Area, about a dozen miles ahead.

The engine shut down and all the dashboard warning lights lit up with the Service Area Ahead sign in view:

Out of Gas - Service Area Ahead
Out of Gas – Service Area Ahead

All the “facilities” are blank because they’re rebuilding the whole place, with the gas station remaining open.

So I slapped the shifter into neutral and we drifted slowly along the shoulder, under the bridge visible ahead, and eventually came to a halt at the beginning of the exit lane.

There was only one thing to do:

Out of Gas - Walking On
Out of Gas – Walking On

Some storytelling later:

Out of Gas - Walking Back
Out of Gas – Walking Back

Just because I could:

Refueling - GPS Track
Refueling – GPS Track

For what are, I trust, understandable reasons, I started the tracker after I began hiking and forgot to turn it off before driving away.

After figuring out the devilishly complex spring-loaded anti-spill spout on the gas can, we drove 1500 feet to the Service Area:

Out of Gas - Service Station
Out of Gas – Service Station

As usual, I filled the tank until the nozzle automatically shut off, for a total of 13.554 gallons in two transactions:

Pump Receipts
Pump Receipts

Now, it is possible the Forester fuel system has another 2.3 gallons tucked away somewhere, but if that reserve doesn’t make the wheels go around, it’s not doing me the least bit of good.

The fact that I’ve occasionally added just short of 14 gallons suggests the estimated remaining capacity depends strongly on the average mileage up to that point and I have come very very close to running out of gas on several occasions.

As far as I can tell, the usable fuel capacity is a scant 14 gallons and the Low Fuel Light goes on with, at most, a dozen more miles in the tank.

This is the second time in more than half a century of driving I’ve run out of gas.

My father was right and I shall henceforth mend my wayward behavior.

Machine Shop, Oddities, Science

Tree vs. Guide Rail: Sheared Bolt

Spotted on a walk along the Mighty Wappingers Creek after a storm with plenty of gusty winds:

Tree-smashed guide rail
Tree-smashed guide rail

The tangle of branches and logs came from a tree that fell across the road from the far right side and put that crease into the guide rail. The vertical stump seems unrelated to that incident.

A bit of rummaging at the base of one post produced a victim:

Tree-smashed guide rail - sheared bolt - side
Tree-smashed guide rail – sheared bolt – side

The impact produced enough force to turn the rail brackets into guillotine metal shears against the posts:

Tree-smashed guide rail - sheared bolt - end
Tree-smashed guide rail – sheared bolt – end

It’s not a clean shear cut, which isn’t surprising under the circumstances.

An ordinary ½-13 Grade 8 bolt has a 17 k pound proof load: popping that bolt required a mighty oomf.

Memo to Self: stay indoors during windy storms!

Oddities

First Year Diary

Another layer of the memorabilia box produced my mother’s 1953 diary, with the first entry in my father’s hand:

Diary - March 18 1953
Diary – March 18 1953

With the benefit of hindsight, some entries stand out:

Diary - May 2 1953
Diary – May 2 1953

These were certainly not fresh from the garden:

Diary - May 8 1953
Diary – May 8 1953

Perhaps reaching this stage required some persuasion:

Diary - June 30 1953
Diary – June 30 1953

This required me to be outdoors:

Diary - July 2 1953
Diary – July 2 1953

Mom’s case of “strep throat” required three penicillin injections to knock it down:

Diary - July 22 1953
Diary – July 22 1953

I get up a little earlier and go to bed a little later nowadays, but I see absolutely nothing wrong with any of this:

Diary - August 27 1953
Diary – August 27 1953

My eyesight was much better back then:

Diary - September 29 1953
Diary – September 29 1953

Definitely an omen:

Diary - December 8 1953
Diary – December 8 1953

My parents ran a restaurant out of the house:

Nisleys Restaurant sign
Nisleys Restaurant sign

As you might expect, the diary tapers off after the first year.

Administrivia, Home Ec, Oddities, Science

Lyme Disease

For reasons that made sense at the time, two weeks ago I ventured outside the house. A few days later, this appeared:

Lyme Disease - arm rash
Lyme Disease – arm rash

The pallid skin over on the left comes from a bike glove. The central bump is one of those annoying sebaceous hyperplasias appearing after a Certain Age and not relevant here.

Having been around this particular block a few times, Mary recognized the diffuse red rash, sleeping 30 of 36 consecutive hours, and a day-long 103 °F fever as Lyme disease. I’m currently taking 100 mg of doxycycline twice a day and (after a week) feeling better, while sleeping a lot more than usual at random intervals during the day.

We’re both highly aware of Lyme disease: Mary routinely dresses in a complete overlayer of permethrin-sprayed clothing and I generally strip-and-shower immediately after any yard work in similarly sprayed, albeit less enclosing, attire. In this case, we think a tiny Deer Tick nymph affixed itself to the outboard side of my wrist, where I could neither see nor feel it, and (because I didn’t take a shower after being outside for only a few minutes) remained attached long enough to infect me.

Caught and treated early, Lyme disease generally does not progress into “post-treatment Lyme disease”, an ailment rife with what can charitably be described as serious woo, despite some evidence of actual disease.

Some of Mary’s Master Gardener cronies have endured co-infections of Babesia microti and we’ll be watching for those symptoms after doxycycline tamps down the obvious problem.

I’ll be puttering very carefully around heavy machinery and posting irregularly for a few weeks …

Memo to Self: the Basement Shop has a lot to recommend it!

Electronics Workbench, Recumbent Bicycling, Science

Tour Easy: Bafang 11.6 A·h Range

After a few days of riding, the Bafang 500C display on Mary’s bike gives the battery status:

Bafang 500C display - 48 mi 30 pct
Bafang 500C display – 48 mi 30 pct

The thermometer scale on the right shows 30% remaining battery capacity after 48.3 miles of riding, with the 11.6 A·h battery at 47.3 V.

For our type of riding, each 10% increment of battery charge delivers about 7 miles of range. Although we could probably get 70 miles between charges, recharging the battery at 20 to 30% makes more sense; the bike is in the garage, so why not?

Our typical 10 to 15 mile rides now average 12+ mph, with some level sections ticking along at 18 mph (giving me some serious exercise), which isn’t much by pro rider standards.

Computing the lithium battery charge state by measuring its voltage isn’t particularly accurate, but it’s about as good as you’re going to get.

Electronics Workbench

Enover Outlet Timer: Over-powered Zener Diode

This being the season of lights, I deployed some outlet timers to turn them on at dusk and off at bedtime. The timers spend much of the rest of their lives plugged into outlets in the Basement Laboratory to keep their internal NiMH backup batteries charged, although they’re not controlling anything:

Enover outlet timer - overview
Enover outlet timer – overview

This one is labeled ENOVER, but it’s essentially identical to all the others sporting random alphabetic names; I have a few more labeled UKOKE in the same plastic case. The current crop uses a different case and has one fewer button, but don’t expect any real difference.

One of the timers had a blank display and didn’t respond to button pushes or a pin punch poked in the RESET hole, so I dismantled it to see what was inside.

Both the hot and neutral terminals had stray wire strands:

Enover outlet timer - stray wire strand
Enover outlet timer – stray wire strand

The power board had the usual missing components, suggesting it had been cheapnified after passing whatever regulatory inspection it might have endured to get a CE mark on its dataplate:

Enover outlet timer - power board - overview
Enover outlet timer – power board – overview

The alert reader may have already noticed the mmmmm smoking gun:

Enover outlet timer - scorched diode
Enover outlet timer – scorched diode

Incredibly, Z1 has a part number wrapped around it! A quick lookup shows a 1N4749A is a 24 V 1 W Zener diode, neatly matching the 24 V relay. The datasheet gives a 10.5 mA test current and a 38 mA maximum regulator current, with a caveat: “Valid provided that electrodes at a distance of 10mm from case are kept at ambient temperature”

The relay datasheet says 8.3 mA nominal coil current, a mere 200 mW, which is much easier to dissipate in wire wrapped around a steel core than in a little diode.

Evidently the poor diode ran rather hot before becoming a dead short, because a phenolic PCB (definitely not at ambient temperature) ought not discolor like that.

Indeed, measuring Z1 in another, still functional, Enover timer showed 25 V and a similarly discolored patch around Z1, suggesting the circuit design requires a bit more disspation from the diode than it can comfortably deliver.

I replaced it with a 1N970B from the Basement Laboratory Warehouse, rated for only 0.5 W in a seemingly identical case, buttoned the whole thing up, and left it in the middle of the concrete basement floor overnight. It wasn’t smoking and continued working in the morning, so I defined things to be no worse than before and declared victory.

Should when the next one fails the same way, I’ll epoxy a small heatsink to that poor diode and its leads to reduce its overall temperature.

For future reference, the underside of the PCB shows a distinct lack of post-soldering flux cleanup:

Enover outlet timer - power board - solder side
Enover outlet timer – power board – solder side

I swabbed it with denatured alcohol, although doing so certainly didn’t make any change to its behavior.

Memo to Self: no-clean flux is a thing.

It’s worth noting no other components show signs of overheating, despite the diode becoming a short circuit, so R1 (a big power resistor) is most likely the shunt regulator’s dropping resistor and can survive the additional power.

Should the diode fail open, the rest of the circuitry will be toast.

Home Ec, Machine Shop

Painting By Numbers, Redux

Five years later, the digits I painted with Rust-Oleum Rusty Metal Primer have weathered pretty well, while the original ink has fallen off the retroreflective sticker:

Mailbox numbers - original vs primer
Mailbox numbers – original vs primer

As before, I wiped off the crud with denatured alcohol and painted neatly inside the lines. The other digits on both sides still look as good as the day I painted them, with only a few bubbles and nicks.

Memo to self: Next time, buy a big sheet of 3M retroreflective film, make a stencil by vinyl cutting, paint the entire number in one shot, and be done with it.