Thursday, August 10, 2023
It's the ideas
Sunday, February 12, 2023
How to trace a parasitic draw
Use a multimeter (not a VOM). Put the multimeter in ammeter mode (<10A). Make sure to switch the common to the correct socket. Make sure the key switch is off and the key removed. Take off the negative terminal of the battery. Put your foot on the brake pedal to drain any remaining current in the circuits. Hook the red probe to the disconnected negative terminal connector and the black probe to the battery. Look to see if there is a current draw, any more than a milliamp or two. If there is not, revise your hypothesis and suspect the battery. If there is, pull the fuses and replace them one by one until you find the fuse that makes the number on the multimeter readout drop significantly when you pull it, then troubleshoot that circuit. Trace it backwards from whatever utility it runs, disconnecting connectors in sequence moving towards the battery, until you unhook the connector that makes the number on the multimeter drop. The faulty circuit is now isolated.
Tuesday, February 7, 2023
EVs vs Ice
r/sustainability question: EVs seem to be all the rage when thinking of ways to sustainably travel, aside from, of course, public transit, but how does the price stack up to traditional ICE vehicles? Are they worth the switch, or is it just going to drain the wallet?
How do electricity rates stack up to gas prices? What about maintenance costs?
Lots to consider, let me know your thoughts.
Intelligent Tinkering: The only way an ICE vehicle beats an EV for ease of use, cost effectiveness, and GHG emissions/mile is 1) if it's a plug-in hybrid used properly, so the first roughly forty miles are EV miles but there is no range limitation or worries about winter heating shrinking range in a cold climate, or 2) if the standard offer electricity supply in the region is particularly dirty with coal and no attempt is made to mitigate, or 3) it is used for heavy work where the energy density needs for efficient use are higher, so heavy towing, snow plowing, and so on, or 4) if it is an older ICE vehicle that has outlived multiple average vehicle lives. Embodied emissions in EV vehicles mean that they are not climate neutral even when run on solar, and the ratio of lifetime fuel consumption to embodied emissions for an ICE vehicle is about five to one, so it is not so hard for an older ICE vehicle that has exceeded multiple average lifetimes to catch up with an EV in total emissions/mile (including embodied emissions). We should note that the "error bars" on applicable studies of embodied energy in EV manufacture remain high. This is because of doubt in the energy costs of materials sourcing.
https://www.iea.org/data-and-statistics/charts/comparative-life-cycle-greenhouse-gas-emissions-of-a-mid-size-bev-and-ice-vehicle
Wednesday, February 1, 2023
Sludged up or bad switch?
Kubota tractor owner: What is the simplest way to clean out the crank case? Manual says rinse with kerosene and somehow wipe it down. I'd like to pull the pan and rinse from the top. Also r&r the oil pump. Pull the engine or pull the front axle? Did an oil change and new oil is filthy after a short run and oil pressure light is on. Should also mention B6000 4x4.
Intelligent Tinkering: If the oil pressure light wasn't on before the oil change and is on now, you probably should make sure it is actually working. It should go off at higher rpm. If it doesn't, I'd suspect the pressure switch. You can take it off and check with a VOM set to the continuity setting, using air pressure (turn the compressor output down to less than 30PSI), or check it by replacing it. If that doesn't help, there are two causes of low oil pressure: bad pump or bad bearings. Bearing wear is far more common than pump wear because the design of the pump is robust. When bearings wear, their ability to hold pressure drops. But typically the light will still go out at higher rpm. It's unlikely the sludge has accumulated in the oil passages. I've stripped down a lot of engines and any sludge is usually just in the sump.
Tuesday, January 31, 2023
Wood burning worries
Question from a sustainability student:
In the last few years I've seen demands that using wood as a power/heat source (by burning it) should not be declared sustainable.
I understand that burning wood releases particulates. I also understand that sometimes we burn woods from forest that are not reafforested which is obviously unsustainable.
However, if we filter the particulates while burning wood and we reafforest the forests that the wood comes from, isn't burning wood sustainable? What am I overlooking?
Mick's answer:
We burn wood for 80 of our heat (in total energy terms), about half or less our heating costs. We harvest about half of it from our own woodlots at a rate of about two cords a year. The remaining trees in our woodlots are growing, and some are growing faster as a result of "tree release", getting more sunlight. Our trees are sequestering far more carbon than the small amount we take each year. We have seven acres and take up to two cords. Using typical averages (of cords produced per acre and weight per cord) for New England hardwood forests, that means we are sequestering 8 to 10 tons/tonnes a year (very roughly), some of which forgives the logging needed for our other two cords which we buy and some proportion of the fossil fuel needed for our stove and vehicles. The trees we take are all ash, which is threatened by the invasive emerald ash borer and will very likely die anyway. The larger mass particulate pollution from wood burning, which contains far less aerosolized component than the equivalent from gas, oil or coal, typically falls out of the atmosphere after only a few miles at the most. It is a form of pollution that is predominant (and harmful) in cities, not in low density rural areas like ours, where they are only 21 people per square mile, and so what particulate there is, is diluted. The biggest sustainability problem with wood burning is when large scale power plants add wood biomass to the fossil fuels used in turbines. So, for instance, woody biomass in the southern US is clear cut from plantations and even natural forests, then shipped to Britain where is is burned in old coal fired plants like Drax in Yorkshire. This industrial use of wood is far less sustainable because a) natural forests store carbon in the soils and much of this is lost when clearcut, b) the fossil fuel used in transportation and processing, and c) the much larger density of particulate produced on-site. It is only cost effective because of "perverse" economic incentives set up by EU carbon regulation.
https://newenglandforestry.org/wp-content/uploads/2019/10/NNE-carbonstorage-100119.pdf
https://www.bbc.com/news/science-environment-63089348
BTW, what I like about this question is that it neatly illustrates the wide variety of disciplines needed to solve sustainability problems.
Wednesday, November 23, 2022
And if you don't believe me...
... to be a serious person you would need to read (all) this first before you say anything:
And this:
https://scholar.google.com/scholar?hl=en&as_sdt=0%2C20&q=does+distance+education+work&btnG=
Now, obviously as a lifelong practitioner of the educational theory of Kurt Hahn, I'm biased. Hahnian teaching requires physical contact, not just physical presence. But let's remember that Unity College was one of a handful of Hahnian colleges in the US and so unique in that role. It was disposed of, unthinkingly, by a decision process that did not even consider the full nature of what was to be lost.
I doubt very much that the board even knows what kind of education was previously provided. You'd think they would at least know who Kurt Hahn was. But I doubt it very much.
So, read this too:
https://scholar.google.com/scholar?hl=en&as_sdt=0%2C20&q=educational+theory+of+Kurt+Hahn&btnG=
Distance learning doesn't work well
Duh!
I mean, ask any experienced in-person educator that has tried distance learning, or worked on a later sequential class with students that took the previous class remotely and those who didn't, in the same class.
Oh. I forgot. We're not allowed to talk to the teachers any more. Not without going through the President first.
https://www.washingtonpost.com/education/2022/11/23/covid-research-remote-school-poverty/