The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

Category: Science

If you measure something often enough, it becomes science

  • Too Many Deer: Another One Bites the Dust

    Too Many Deer: Another One Bites the Dust

    I passed another dead deer on New Hackensack Rd while hauling groceries home:

    Deer Collision - roadkill - New Hackensack Rd - 2021-09-08
    Deer Collision – roadkill – New Hackensack Rd – 2021-09-08

    The next day I walked past the other side of the collision at the corner gas station’s dead car collection:

    Deer Collision - front end damage
    Deer Collision – front end damage

    A closer look at that nice rounded dent links the two contestants:

    Deer Collision - front end damage - deer hair detail
    Deer Collision – front end damage – deer hair detail

    The impact didn’t blow the airbags, so maybe the car isn’t a total loss, despite extensive front end damage and some scrap metal inside the engine compartment.

    As far as I can tell, Vassar College has been holding a deer cull every January, but taking out a few dozen deer definitely hasn’t eliminated the road hazard. If the folks objecting to the cull set up a fund to help drivers damaged by the objects of their affection, it’d demonstrate their understanding of the problem.

  • Tenergy 18650 Lithium Cells: Four Years of Running Lights

    Tenergy 18650 Lithium Cells: Four Years of Running Lights

    With the amber daytime running light connected to the Bafang’s headlight output and the Anker flashlight on the other side of the fairing getting fewer power-on hours, it’s a good time to see how those four Tenergy lithium 18650 cells are doing:

    Tenergy 18650 Protected - 2021-09-09
    Tenergy 18650 Protected – 2021-09-09

    The overall capacity is down by 10%, with the voltage depressed by 120 mV over most of the curve.

    Although I don’t keep daily records, the back of the envelope reveals 150 to 200 hour-long rides per year during the last four years, so call it 700 charging cycles:

    Anker LC40 Flashlight - Anodizing fade
    Anker LC40 Flashlight – Anodizing fade

    High brightness draws 1.5 A and low is 50% duty cycle, so a typical ride requires 750 mA·h = 2.5 W·h. Each cell lives for three or four rides with the LED set to low brightness and the numbers work out close enough.

  • The Patience of Trees: Guide Rail

    The Patience of Trees: Guide Rail

    Found behind a store in Red Oaks Mill, overlooking the Mighty Wappingers Creek:

    Tree stump around guide rail
    Tree stump around guide rail

    The old rail fell off its (long gone) post before the tree grew around it and the newer rail (upper right) definitely isn’t fresh from the factory, so this tableau has been on display for quite a while.

    The tree’s growth rings have pretty much weathered away.

  • Red Oaks Mill Dam: Flood Stage

    Red Oaks Mill Dam: Flood Stage

    The remnants of Hurricane Ida dropped half a foot of rain in our area, so we walked to the remains of the Red Oaks Mill Dam to see the water:

    Red Oaks Mill Dam - 2021-09-02
    Red Oaks Mill Dam – 2021-09-02

    The white water crests stand in place over rocks in the stream bed, with hypnotic flowlines.

    The concrete abutment over on the left is now completely submerged. It was more conspicuous in May:

    Red Oaks Mill Dam - 2021-05-17
    Red Oaks Mill Dam – 2021-05-17

    Surprisingly, most of the tree trunks and debris collecting over on the right remain jammed in place, as seen in March:

    Red Oaks Mill Dam - 2021-03-19
    Red Oaks Mill Dam – 2021-03-19

    For completeness, the scene in February:

    Red Oaks Mill Dam - 2021-02-25
    Red Oaks Mill Dam – 2021-02-25

    The USGS has a hydrology station just downstream that reported about 10 feet of water, the “moderate” flood stage, around the time I took the first picture. The normal level is 3 feet.

    The “major” flood stage is 14 feet and, back in 2007, this is what it looked like at 15 feet:

    Red Oaks Mill Dam - 2007-04-17
    Red Oaks Mill Dam – 2007-04-17

    Our reference point is a drain pipe on the retaining wall behind the hotel: when the Mighty Wappingers Creek covers the pipe, it’s well and truly flooding.

    Searching for “red oaks mill dam” will surface more pix and stories.

  • Sticky Trap Results

    Sticky Trap Results

    In late May we deployed six sticky traps in and around the onion bed, attempting to reduce the number of Onion Fly maggots. By mid-June the sheets were covered with the shredded leaves Mary uses to mulch the onions, but half a dozen flies were out of action:

    Sticky trap - 2021-06
    Sticky trap – 2021-06

    We’re pretty sure that’s what these things are:

    Sticky trap - Onion Fly - 2021-06
    Sticky trap – Onion Fly – 2021-06

    They’re supposed to have red eyes, but being affixed to a sheet of snot for a few weeks doesn’t do the least bit of good for your eyes.

    We replaced the sheets and left them in place until the end of July:

    Sticky trap - 2021-07
    Sticky trap – 2021-07

    The sheets took another half-dozen flies out of circulation, Mary began harvesting the onions, and observed it was the healthiest onion harvest she’s ever had.

    We declared victory, removed the traps, and the remaining onions suffered considerable maggot damage over the next few weeks.

    Anecdotally, it seems reducing the Onion Fly population by (what seems to be) a small amount and maintaining pressure on the population dramatically reduces the number of maggots available to damage the onion crop. At least for a single bed in a non-commercial setting.

    The plural of anecdote is not anecdata, but we’ll try it again next year, leave the traps in place while the onions are in the ground, and see what happens.

  • Tree Frog Redux

    Tree Frog Redux

    Mary found another tree frog while picking Savoy lettuce for breakfast:

    Tree frog on Savoy cabbage
    Tree frog on Savoy cabbage

    They’re much better camouflaged in their (more or less) natural surroundings, so I didn’t spot it at first, either.

    They really are cute little gadgets:

    Tree frog on Savoy cabbage - detail
    Tree frog on Savoy cabbage – detail

    This is only the fourth tree frog she’s seen in the last two decades, but the second one in a month. It may be the same frog as before, although the garden now has a rather husky resident snake who seems to be eating well.

  • Tour Easy: Bafang 11.6 A·h Range

    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.