Turquoise Energy Ltd. News #55
Victoria BC
Copyright 2012 Craig Carmichael - September 3rd, 2012


www.TurquoiseEnergy.com = www.ElectricHubcap.com = www.ElectricWeel.com = www.MushroomOutboard.com

Hilight: Magnetic Refrigeration & Home Heating: vast energy saving potential?

Month In Brief
(Summaries)
- 1912 Detroit Electric Car - 12V Fridge - Magnetic Refrigeration - Sprint car tests - 3D printer

In Passing (Miscellaneous topics and editorial comments)
- Wind versus wave power on the sea: immense work to obtain the lesser energy source.
Our dysfunctional, failing society:
- Einstein Refrigerator 1930. Even Albert Einstein fell into the "technology death by patent" trap - Self centered versus love centered training? - Democraship, the kleptocracy, and state terrorism - an effective cancer cure and why it'll go nowhere - Widespread crop failures magnify financial crisis problems - Victims of Bank Fraud.

Electric Hubcap System
* Motor Assembly
* Brake Vacuum Assist - pump & reservoir
* Safety: "Stealth" electric cars should make warning noise when in proximity to people?
* Sprint car: motor, controller and battery installed. It moved a little: the motor controller seems to be the problem rather than the torque converter... makes the motor "wimpy".
* The Planetary Gear Torque Converter Looks Like a Keeper!
* Motor controller improvements.
* A new type of control modulation: combined CRM + PWM.

Planetary Gear Torque Converter Project: Converter seems to work acceptably in car!
* 3D Printed plastic planetary gear/torque converter parts?

Solar Electricity Project
* Electricity is already 40¢/KWH in Hawaii, making solar a 3-5 year payback.
* Super battery stick proves less than super - also beware voltage drops to batteries!

Superinsulated Thermoelectric Fridge & Freezer
* Single Peltier cooling works best after all. (Also can work well without cold-side fan.)
* Better fridge shapes can provide more internal volume with less exterior wall surface to keep cool - octagon, Low walls and terraced sunken floor, geodesic dome.
* Dividing fridge with a wall(s) allows sufficient cooling of a smaller space in summer heat, ice compartment.
* Magnetic Refrigeration & Home Heating - world's best research into it: Victoria BC -  a design implementation - rare earths ordered - potential for thermomagnetic motion machines using gadolinium.
* Regular Chest Freezer used as low energy Refrigerator

Turquoise Battery Project
* Project devolves to assembling 3D printer to make electrode pockets etc.
* Battery Making Video planned.

No Project Reports on: Magnetic Motion Devices, Weel motor, DSSC solar cells, LED Lighting, Pulsejet steel plate cutter



Newsletters Index/Highlights: http://www.TurquoiseEnergy.com/news/index.html

Construction Manuals and information:
Electric Hubcap Motor - Turquoise Motor Controller
- 36 Volt Electric Fan-Heater
- Nanocrystalline glass to enhance Solar Cell performance - Ersatz 'powder coating' home process for protecting/painting metal

Products Catalog:
 - Electric Hubcap Motor Kit
 - Sodium Sulfate - Lead-Acid battery longevity/renewal
 - NiMH Handy Battery Sticks
, Dry Cells
 - LED Light Fixtures
Motor Building Workshops


...all at:  http://www.TurquoiseEnergy.com/
(orders: e-mail [email protected])



August in Brief

   I was asked to run the August first meeting of the VEVA - Islands electric car club, as Cam Rawlinson was on the mainland picking up the 1912 Detroit Electric car for a Victoria tour to celebrate it's 100th year, making it now a genuine antique. This was appropriate as the car was bought by a Victorian and it spent most of its life here. Running the meeting consisted of telling people that the Detroit had missed the 5PM ferry but would arrive about 8:15. To my surprise the midsummer meeting was the best attended so far - owing to interest in this car.
   Its drive arrangement with the motor underneath connected to the rear differential gears, is essentially similar to today's iMiEV (available off the lot at Mitsubishi Motors on Cloverdale St). Of course, performance and style are almost incomparable. The NiFe batteries regrettably at long last wore out, and have been replaced by short lived but cheap PbPb's, under the hood and in the trunk.
   This Detroit Electric is in admirable condition, and it won the Oak Bay Mayor's pick at the Classic Car Show on Oak Bay Avenue.


   On top of several more sundry things on my list for the month, I really wanted to get the motor together and into the Sprint car, get the Peltier cooler fridge finished, make the magnet machine that's been in my head for 2 or 3 months now, and put the 3D printer kit together.
   Later on I started thinking about grinding up some of the nanocrystalline borosilicate glaze I made a while back and melting it into 'pebble lenses' facing some solar collector cover glass (using the broken solar collector), about making a video about making batteries, which someone requested I do a month or two ago, and about ...yet another... new project: magnetic heat pumping.

   Things seemed to move at a crawl in early August, with one interruption to the work after another. I didn't get much done around the house either, and the days were into double digits before I got going on much of anything after the July TE News. I guess that's summer! Even ordering some electronic parts - mostly for LED lighting - was put off until it didn't get done at all. Then there were exciting things on the 30th and 31st that kept me from getting this newsletter out quickly as September started.

   On the 9th someone phoned from Pennsylvania asking about thermoelectric fridges. Since all I had was the July newsletter writeup, this seemed to indicate a hungry market for them, or perhaps for a ready-made Peltier cooling system for doing them DIY.
   The cooling system went back to a single Peltier element, which works better after all than double. (Oops!) A foam divider wall inside the fridge allowed it to provide fridge temperatures in a smaller space in the heat of summer. With no fan inside, the inner heatsink would frost up and the temperatures dropped almost 20º to 4-6... at least near the bottom of the 1/2 fridge. But I didn't finish up the fridge itself (yet). Instead, an exciting new type of refrigeration crossed my radar screen and occupied my time in study: magnetic heat pumping.

   Following TE News #54, someone sent me a Wikipedia link to magnetic refrigeration. This has been experimental for quite some time, but it seemed to me the way it was being done, by pumping a fluid or a gas to move heat around, was (as is so often the case) needlessly complicating the entire idea. Later I found out that the fluid friction also severely limits the theoretically very high coefficient of performance.
   I soon thought up what I believe should be a better "solid state" design. As I see it, scientists have created the "vacuum tubes" of magnetic heat pumping and I have (in concept) the "transistors". (That analogy is appropriate, but probably overstating the case somewhat.)
   As conceived by month's end, the first main component is supermagnets aimed down on a horizontal rotor turned by a motor, to provide the on-off magnetic field that heats and then cools gadolinium as it enters and then leaves a magnetic field, by the magneto-caloric effect (MCE). The other component is stacks of thin, flat solid plates: stationary copper heat absorber and releaser sheets in a plastic frame, alternating with loose gadolinium "wafers". Each wafer may get warmer and cooler by 1/2, 1 or more degrees, and the number of stacks and wafers required for the desired temperature spread will depend on the actual values attained. The magnetic force as a rotor magnet passes by, pulls each gadolinium wafer up into contact with its upper copper heatsink within the stack, and also heats it, thus heating the heatsink. When the magnet has passed, the wafers fall down and contact the lower copper heatsink, and they cool. It seems to me this should be very effective at pumping heat from the bottom of the stack to the top, and [almost] everything looks simple and straightforward to make.

   On the 21st I ordered some erbium and some gadolinium - the magic element with a large MCE at 293ºK (room temperature), its magnetic Curie temperature. An alloy of Gd and Erbium (85:15%) has a Curie temperature of 278ºK - fridge temperature. [Gadolinium is "malleable and ductile", so I hoped making ingots into flat wafers wouldn't be too hard. Erbium is "malleable".]
   Twice the Gd and no Er arrived on the 31st. Oh well, good enough to start with, and I got the better bargain in price, Gd for the price of cheaper Er. It proved magnetic enough to be picked up (about equally at room or fridge temperatures), but not clamping strongly to the supermagnet like iron or steel. Perfect! "Rolling resistance" of the magnet rotor should be low, so a low power motor should work fine (hmm... where's some old audio cassette deck?)... Just how much cooling can be effected, from how little power?
   Temperature of a chunk went up or down about .3 degrees entering or leaving a supermagnet's field. Obviously I'll be wanting to get the strongest possible field and I might review prior designs again and take note of the ways others got the most flux.
   Gadolinium also seemed harder than mild steel when I went to cut a piece. Since it also oxidizes readily and has a high melting point, it may be tough to form it into the required metallic 'wafer' sheets.

   It seems to me magnetic heat pumping has far more potential than just refrigerators. A 1500 watt electric baseboard heater might be replaced, not with a 1000-1200 watt peltier elements heat pump, but instead with a 300 to 600 watt magnetic one. The global potential for winter energy saving from this new technology looks staggering! It probably has excellent potential for hot weather air conditioning too.
   This was the only 'magnetic machine' that got looked at in August.

   Arriving with the Gd metal was Sm2O3 powder, samarium oxide, which I think should be about the best substance for raising oxygen overvoltage in the batteries. It was convenient to get some while I was placing a rare earths order anyway.

   Aside from there being all the other things I was doing, I had acquired almost some mental block against working on motors and cars. I tackled each small step on the motor without enthusiasm and then a day or two would slip by before I did one more. Perhaps it comes from 3-1/2 years of not even getting a car to move. In spite of ongoing improvements to the motors and the controllers over that time, finally having what ought to be a working torque converter, and a lightweight car with a 4 to 1 final reduction gear, I had little faith that the car would actually move. What would go wrong this time - some new variety of catastrophic failure, or simple refusal to budge when I thought there should be up to maybe 200 foot-pounds of available torque at the wheels?

   Notwithstanding, the motor was finally done and mounted in the Sprint car on the 27th. It looked good and seemed to fit well, which seemed inspiring, so then I put in and wired the controller (29th), followed by the 36V, 20 AH NiMH battery box I made a while back (30th), and tried it out.
   The car moved, but not much. The motor controller seemed to be the main culprit rather than the torque converter. My present analysis is that the torque converter seems to work, but it takes more power going to it from the motor than I expected to budge the car.
   At one point it did roll forward a ways, but on a slight downhill slope. It only needed 20-30 foot-pounds at the wheels to do that. The rope tended to jam and not let the pulley slip, even when it was loose, especially in one direction. The driver controls in the car worked fine. The motor ran fine, but in reverse the helical planetary gears caused the planets assembly with the pulley to push over sideways and rub on the housing. With the test controls by the side of the hood, I disconnected the clutch rope and pulled it by hand. At one point, it looked like it was about to move backwards, which needed 50-60 foot-pounds, but the motor stalled. Finally, trying to repeat this, I put on near maximum power to the motor and pulled hard on the rope. The motor slowed to a crawl and then the controller made a bang and smelled like blown transistors. A 'minor' design problem was fixed and the controller repaired by Sept. 2nd.
   On reviewing the videos of the tests on September 2nd, I noticed that the motor seemed wimpy at times, and that the cause would be the CRM 'direct torque control' modulation. Each time the car started moving or I put more tension on the slip rope, the motor started stalling, and one had to be really fast on the 'throttle' to give it more torque. I conceived of a new combined CRM + PWM control modulation that would deliver the best of both types.  I hope to make an external PWM circuit and try this out very soon with further car tests - while the weather is still nice.


Video of tests uploaded to youtube (click image for video; 'Back' to return)
Here the car started moving as I applied tension to the rope,
but at the same time, the motor started slowing and stalling.

   The 3D printer assembly absorbed quite a few hours I would otherwise have put into the car conversion and other things. It was well advanced but not complete when I stopped working on it to get the car installation ready to test.





In Passing
Incidental news, editorials

Wind Versus Wave Power

   I watched an episode of "Mega Builders" on Netflix where a vast field of windplants was being installed on the North Sea off of Holland. The plants were colossal stuctures, sticking up out of the ocean on immense pillars. With such immense pieces, the project was very large in scale. One piller held an electrical substation with a very high voltage cable to the shore. Much was said about the roughness of the sea and the hazards and delays it caused in construction.
   I think it's amazing how so much effort and expense was expended to capture wind power, on the sea, when the power of the sea beneath was doubtless much the greater, and probably more easily extracted. And if one is going to erect pillars sticking up from the sea bottom anyway, they'd make better, simpler platforms for wave power floats, mechanics and generators than floating units as proposed by me and others.
   Perhaps I wasn't thinking big enough in designing floating wave power structures that could simply be towed into place, the anchor dropped, and the cable plugged in on shore.

Invention death by Patent: even Einstein fell for it!

   Here is just one more instance of the most common use of patents: to kill valuable new technologies. (Wikipedia article Einstein.) What a crooked system the patent system is! If even Einstein fell into the trap, whoever has a hope of evading it?

Einstein refrigerator

In 1926, Einstein and his former student Leó Szilárd co-invented (and in 1930, patented) the Einstein refrigerator. This absorption refrigerator was then revolutionary for having no moving parts and using only heat as an input.
On 11 November 1930, U.S. Patent 1,781,541 was awarded to Albert Einstein and Leó Szilárd for the refrigerator. Their invention was not immediately put into commercial production, as the most promising of their patents were quickly bought up by the Swedish company Electrolux to protect its refrigeration technology from competition.

   The patents would have expired about 1948, and I suppose my dad was lucky to find a propane fridge for our cabin in about 1960. By that time, electricity was available most places and the value of the technology to the market was very limited. I've only seen 3 or 4 of these fridges in my life, and two of them were the ones my dad bought. (The second one was bigger and easier to light.)

Teaching youth: focus on self centered, versus social centered

   I remember the class being told in grade 1 (or was it 3 or 4?), a couple of times, that we needed to get an education, or we'd "end up digging ditches". We needed an education so we could get a better job and be more affluent. There was an implicit, and common, hidden message in this: that everybody was in life for themself and each should look out for "number one". (At the same time, we daily recited the Lord's prayer asking for "Thy will be done on Earth" - but that was just a jumble of words that didn't even make any grammatical sense, and which were never explained to us. "Thy what will be done on Earth"? "Our Father that art in heaven":... did he spend his time painting pictures? Why wasn't the prayer made of proper sentences?)

   Material man must "serve two masters", looking after material needs while trying to attain meaningful intellectual and spiritual goals beyond. But "the self" is an insidious focus to instill in young people. "How can I make more money?" - materialism, consumerism - is a hollow, unsatisfying philosophy to live by. Often the best answers found to this shallow question have little to do with serving one's fellows or improving society, and contribute little to growth of a dynamic character. Instead the focus may become how to get the most the easiest way, which may devolve essentially to a mentality of robbery. At worst people may progress to the greed and avarice that are presently running rampant and destroying civilization.

   In corporate terms it's called "externalizing": We're here to make money. The problems our activities inflict on the society we all live in aren't our problems; somebody else can deal with them - we'll pay a tax or a fine to allow someone else to deal with them. (but if you charge us much, we'll move offshore.) A corrupt culture of scarcity, greed, abrogation of responsibility and gangster elitism has arisen.
   The attitude that advances true civilization and the cause of human brotherhood is of course "How can I best serve my fellow man?"; "How can I do the most good?". Since one can't contribute while trying to find one's next meal, making a decent living, hopefully doing things one enjoys doing, is implicit. So is safeguarding this co-operative culture by eliminating opportunities for greed and corruption as well as prompt prosecution and demoting of anyone engaged in it, _especially_ by those who have been granted positions of power and influence over others. And when everyone is contributing or at least prevented from working mischief, everyone is safe from violence and want, and lives better.

   Our present civilization makes no organized effort to visualize how we want to live as the future unfolds. There are no "Departments of Progress" committed to and administering working towards worthy goals. Instead, people and "for profit companies" are in it 'for themselves' and no one is left with any power or resources to solve the 'externalized' problems, or to contribute to the greater good. The "status quo" powers simply try to put out fires and maintain themselves, without even trying to remove the kindling or prevent the fires from starting, without an overriding plan. Those who conceive plans are locked out of the societal structures of political and economic control.
   Someone likened what's been happening for many decades, even a century, to a frog in a pan. If he's tossed into a pan of hot water, he jumps out. If he's tossed into cold water which is gradually heated, there is no point where the frog realizes the danger and jumps out, and he dies. Twentieth century civilization, tolerating every fresh outrage without taking meaningful action, has reached the boiling point of unbridled corruption and is unraveling before our eyes. In the last analysis, its unworkable and unsustainable societal configurations aren't worth saving.
   Moving to a brighter future requires a new all-inclusive morality and higher loyalties, real religious living where the fatherhood of God and the brotherhood of Man are implicit in one's daily living, and real courage to face and manage the serious and perplexing problems just beginning to engulf our planet -- the sort of courage, perhaps, to risk if necessary becoming eligible for the Julian Assange Award for News Reporting, or the Bradley Manning Award for Loyalty to a Higher Cause. Every person who stands up and embodies a righteous cause counts for more than he knows - the angels await such decisions so they can pitch in and help co-ordinate people and circumstances in unseen "synchronistic" ways.

   BTW I never saw a "ditchdigger". Even in 1960 the few ditches in town were being dug with machinery.

Democraship, Kleptocracy: the internal enemy

   In this century, we have rapidly transitioned from having marginally useful civil governments to living in "democraships" where we still have a vote (so far), but no more control or influence over our governments than in a dictatorship. The USA's "kleptocracy" is leading in this. Any dissent or criticism of the US government is now branded "terrorism" by agencies of that government, while that government itself is committing far more acts of terrorism than any other organization in the world. But the USA isn't alone. Other "western" nations are following right along.
   An Israeli posted a Facebook message "We Love You Iran!" which was lavishly responded in kind by many more people in both nations. It touched me. It showed where the sentiments of the majority really lie. But foreign governments are making economic war on Iran, starving the people and driving it to desperation. Israel and the USA especially want to attack it and pillage it, and Iranian society is being held back.
   The US "government" is now also talking about invading Africa. The pretext is to take out some inconsequential villain, "Kona"(?), who, according to a Ugandan-American girl in high school, and her relatives in Uganda, was most probably killed in a US bombing raid on his headquarters 6 years ago. He hasn't been seen or heard of since. In the interview, when the girl mentioned that oil has been found in Uganda along the border with Congo, the real motive became clear. And it seems that although Ugandan oil and Iranian oil aren't really needed with other existing sources filling the demand, and with Canada selling the USA oil from the Alberta tar sands cheaper than any third world country sells its oil, the USA in its paranoia doesn't want China getting oil, so they want to control it all.
   US military personnel are also victims: as they start to understand why they're really there in foreign lands, killing on a genocidal scale, pillaging and despoiling, they're committing suicide in record numbers. There are more suicides than battle casualties. The hierarchy is calling it "stress", but "feeling guilt", not wishing to participate in these crimes against humanity, might be a more common reason.
   I expect we are today probably looking at the last US election. As I've noted the laws are now set up for a dictatorship. The "Republican" faction "primaries" have shown how little Romney and his gang care for the democratic process, even making it illegal for Paul supporters to cast their votes. It appears he'll win the election, and if he does, I think he'll "delay" - call off - the next one on some "emergency" pretext.

   It's becoming increasingly true, and increasingly apparent, that it isn't foreign countries but our own economic-industrial institutions and governments that have become our worst enemies, the enemies of peace, prosperity and liberty. They've lost most any merit they once had, and soon they'll be falling apart along with the global financial system.

New, effective cancer cure

   Dichloroacetic acid (DCA) has evidently been used for decades to treat a rare disease or two. Last year a doctor in Edmonton found a previously unnoticed effect and tested it in mice: it's amazingly effective against cancerous tumors, with few side effects.
   Acetic acid is of course better known as vinegar. (Perhaps instructions for how to chlorinate it can be found on the web?) DCA is cheap and has been around too long to patent. In our corrupt society, it'll go nowhere. It might even be outlawed. It's a diabolical process that eliminates medically effective and cost effective solutions:

* You can't sell something and claim it's good for any medical purpose unless you can clinically prove it. Even if you sell common things known to reduce cancer like almonds, strawberries and vitamin D, if you claim they're effective against cancer without clinical tests, you'll be shut down.
* The clinical tests cost cost tens to hundreds of millions of dollars.
* If you somehow went to all that trouble and expense for an unpatentable substance, it gives you no benefit over others selling the same substance. They can sell it much cheaper because they didn't have to finance your testing, and would also be able to say "clinically proven to...".
* Furthermore, if even a patented substance proves too effective, the patient will be quickly cured and won't be buying it for long enough to help pay back your costs.
* The best business is thus obtained by marginally effective patented drugs that keep the patient alive but without affording a real cure.
* In addition, it's in "big pharma's" extreme interest to ban, or at least stamp out information about, things that will actually prevent or cure disease better than their offerings. Thus we find many insidious things:
  - The US banning of Laetrille (SP?), derived from almonds in 1969. It's now available only in Mexico, where Americans in the know go to get it for cancer treatment.
  - The effective banning of DMSO, a 'home remedy' that was starting to become popular, used effectively by many for various conditions. (It's not even a drug, it's just a solvent. If paint thinner cured medical conditions, it'd disappear too.)
  - Disinformation campaigns: For example, in a short PNW summer where hot sunny days can often be counted on the fingers and the population is chronically seriously deficient in vitamin D, making cancer virtually epidemic here, on that first rare hot, sunny day that the public heads for the beaches, "public service" ads appear on TV reminding everyone how bad sunburn is and advising we all slather on sunscreen (to avoid getting any of those healthy, vitamin D forming rays on our skin). Few die of skin cancers - they're mostly easily treated. Meanwhile, millions die of other cancers because they're too vitamin D deficient to resist tumor growth.

   It's small wonder then that so many are chronically ill and medical expenses go up and up and up. Health and nutrition are areas where the individual is well advised to do enough of their own study to learn some fundamentals. Health care with doctors, healers, drugs and nutrition have a vital role in society, but ignorant reliance on an overblown health care system after a careless, unhealthy lifestyle empowers the greedy to do the things they do to extract millions from everyone.

Global Bank Fraud, coming food shortages

   A UK financial analyst estimated that a hundred million people have been driven into poverty since 2007 as a result of bank fraud. Since people in poverty aren't living well and often die, he suspected that more people have been killed by bank fraud than by all the wars since world war two - perhaps seven million.
   (My own very meager RRSP investment was worth 33% less now than in 1998, 15% less than at the start of 2011, and 6% less than this January. And that doesn't take inflation into account. It didn't average 1% a year over 17 years. If I had bought a chunk of gold, it would now be worth 4x what I put in; silver - 6x. Both have been rising rapidly in this century and won't suddenly drop like stocks. At 57, my plan was now 'unlocked' and tho "sell low" is bad advice in normal times, the writing was on the wall and I cashed it out. In hindsight it would have been better to have done this in 2010 or 2011 -- but better now than before it gets worse or even disappears as many pension funds and futures accounts have.)
   It looks like worse is to come. Corruption and greed will magnify the problems of poor or failed 2012 year crops all over the world: severe droughts across the USA, in Gujarat India, the Sahel and in South Korea, typhoons in China, Taiwan and the Philippines, wildfires in Russia, and an infestation of crop eating mice in Germany (50% losses) are ones I've heard of.
   Seems to me that at one time the USA kept food reserves in case of bad crop seasons. There have been other bad years, but today the larder is bare. Today there are almost no family farms to "go back to", and any failure in the food supply chain, or petroleum to transport food (thanks to corruption preventing and eliminating electrification of the transportation network), can quickly result in shortages, hunger, and perhaps famine and epidemics. With the default (and indeed evident disdain) of governments, responsibility for stocking enough food to ride out times of shortage devolves on the individual.
   Serious man caused as well as natural disasters are obviously in store, and combined with financial collapse, whole nations, large or small, could potentially cease to exist as organized entities overnight.

   But it's all part of a cosmic plan for progress - a necessary evil. This world must move forward from its present evolutionary dead end. The pillars of the corruption are being cast down, and in a disorganized time, unhindered by powerful reprobates, the more enlightened and increasingly spiritual people will learn of and implement sustainable societal structures that can adapt and grow. (I expect that my writings, Fundamental Principles of Democratic Government and the Department of Progress idea will be among the historic documents and proposals read and considered in the processes.)



Electric Hubcap Motor System

Motor Assembly

   By the 13th I had finally cut the keyslots in the shaft for the sun gear and for the SD bushing to hold the magnet rotor on, turned a large center hole in a bearing mount plate for the larger bearing on the fat part of the shaft, and put together a magnet sensor PCB.
   The new, thicker rotor outside body had increased the motor diameter to 11.6". With 10" rotors and bolt holes through the walls instead of within the rotor compartment, those bolt holes had to be moved out about .1", so a new hole drilling template was needed. On the 15th I made the CNC g-code using a spreadsheet, drilled the template, and drilled the motor.
   I still needed a way to lock the sun gear in place, to keep it from sliding off the end of the shaft. I didn't want to put a set screw through it because the only place it could go was through the gear teeth. Instead I needed to put some fitting on the end of the shaft. I ended up with this cludjed arrangement:


Motor shaft with SD coupling to hold magnet rotor (hiding stator end of shaft), bearing,
and sun gear held in place by a shaft key, a sleeve on the shaft, and a flat-head bolt and bent washer on the outside.

   (It may be a saving grace that the outer washer is only stressed when the car is in reverse. How can I reinforce it?)

   As I was busy with other things, it was the 26th before I put everything together. Since the rotor holes had been moved outwards, the holes in the Sprint car mounting plate had to be likewise reamed out to match, and I made good use of the mini milling machine for this (still with hand cranks, not CNC control - luckily).

   I thought of what to do to cover the coils: wrap a narrow strip of furnace type air filter around the motor and hold it in place with some small wires. However, I didn't get around to getting the filter.

 I thought of testing the motor, and I thought of checking out its back EMF voltage levels as this still hasn't been done on the modern versions. Instead I decided to go for the gusto and mount it in the Sprint car and try it in situ. Hopefully I might still get the Sprint running before month's end, if all went well. After some further fiddling and reaming of mounting holes, it seemed to fit well, the sun gear on the shaft centering on the torque converter planet gears.


This is what replaces the car's engine, transmission et al!

Brake Vacuum Assist

   One can only get so concerned with "minor details" before the thing is running, but hey... they're easier to work on than some aspects of the original R & Development work, and they do need to be done before hitting the streets. (And the brakes, preferably before hitting anything anywhere. Although, the Sprint is so small and light I don't see why it should need a vacuum assist. But it's made with it - sigh!)
   Someone gave me a link to cheap Chinese 12 volt vacuum pumps, so I bought one. It doesn't have the speed of suction to do car brake vacuum assist directly, so the thing to do is to hook it to a vacuum storage (anti-storage?) tank. What would hold a vacuum without imploding? It suddenly occurred to me that an empty small propane tank could work, the kind used for propane torches and campstoves. A great feature is the price.
   The guy who gave me the link thought that would be overkill on the pressure capacity, and also that it needed to be about 2 liters. Hmm, that would mean two tanks. Well, maybe a 3" ABS plumbing drain pipe a foot long or so, or a longer 2" one? Or is one liter is big enough for the Sprint?
   I didn't get any of it hooked up, except to mount the pump under the hood. The mass of wiring that went to  the engine will need sorting out. Perhaps the "fuel pump" wires can be "vacuum pump" instead.

Safety Warning?

   Electric cars are beautifully quiet, however there has been some concern about their "stealth". A friend recently said he stepped onto the street and was almost run over by one. He hadn't bothered to look since he didn't hear any traffic. Another friend almost hit one on his bicycle. And there's very few around so far. (Reminds me of Ministry of Transport stations: whenever they added a second vehicle on a small island, there was always a collision.)
   I don't want to make noise unnecessarily, but it occurs to me that some sort of sensor might be used to start some humming or buzzing noise if an anything is too close to where the car is headed. (Something sounding like a hive of angry hornets should grab anyone's instant attention!) It could get louder as the danger from the proximity increases. This would doubtless require computer control to calculate where the danger zone is and how far it was penetrated based on vehicle speed, power, steering, etc.

Motor Controller: Operator controls wiring



The motor & controller under the hood. There was lots of room, but many obstructions and no flat surfaces to mount anything on.
I bolted an aluminum bar where there were two threaded holes together on the fender and bolted the motor controller to the bar.

   I had decided on a single 10 pin "operator controls" header connector in the controller. But what would be on the other end? The Tercel and two arrangements in the Sprint were a bit of a hodgepodge of wires, even with just the Fwd-Off-Rev switch and the 'electron pedal' wired.
   I got an idea to screw on a 10 position screw-down terminal block under the dash in the car, and run a single 10 pin cable to the connector in the motor controller. That way, a mechanically solid connection point in the cab was an exact extension of what was in the controller. The individual 'device' wires could go straight from the device to the terminal block, ending with crimped (& soldered) fork lugs to be screwed to the block. In the Sprint I left the rubber Pico trailer plugs I'd already put in, but they should be a bit superfluous in future installations.
   One improvement would be to have 2 or 3 extra positions on the block to clamp more ground wires, since most everything has a ground wire.

Sprint Car Tests

   On the 30th I installed a 36 volt battery in the Sprint, having put in the motor and controller in the preceding days, and tried it out. On the lawn where and as it was sitting (slight slope), a torque wrench on the front wheel nuts showed it took around 20 foot-pounds to move it forward, and 60 to move it backwards.
   The motor ran fine. But there was notable hesitation and little torque starting from a stop - a persistent controller problem. The slip clutch rope, tho loose, also tended to jam and not let the motor start turning. Evidently it needs a bit less rope angle wrapped around the pulley... or maybe the motor just needs its starting torque improved. In the reverse direction, the helical gears pushed the planets assembly sideways (about 3/16") where the attached slip clutch pulley rubbed on the housing. Simple to fix. The driver controls in the car worked fine. The motor temperature sensor, properly hooked up for the first time ever, gave no reading.
   I had to disconnect the clutch rope and pull it by hand to avoid the jamming, and use the test controls at the hood. The car didn't seem to move as easily as was hoped. It consented at one point to roll forward, with much force required. It looked a couple of times as though it was was about to start rolling backward, but it didn't. I wasn't very impressed by the torque converter at the time, but on reviewing the videos I took, I think it works well enough, and that the motor controller is the real problem.

   Theoretically the car should have rolled even with the jammed slip clutch. The motor theoretically has around 10 foot pounds torque with 100+ amps of current, and with 1.8x speed reduction in the planetary gear and 4x in the chain drive, that's 72 foot-pounds to the wheels to overcome 20 to roll forward. But since the motor is held stopped with no clutch, this would presume good motor torque at startup instead of a hesitancy to start spinning even with no load.


   I put together a short video typical of the tests from clips I took, and uploaded it to Youtube.

( http://www.youtube.com/watch?v=BsW66_lnzFg&feature=plcp )



Here car is rolling forward as I pull on the slip clutch rope to apply tension.

Motor Controller Improvements (sigh!)

   Then in one test, giving the motor high "throttle" and pulling hard on the rope, the heavily loaded motor (probably drawing over 100 amps) slowed to a crawl and there was a BANG! from the controller and the smell of toasted transistors. (luckily just 2, phase B low.) On inspection, the phase A power wires ran right alongside the phase B high gates control wire for about 4cm, an ideal layout for spurious phase B high-side MOSFET turnons and shoot through currents in phase B - but only at very high current loads owing to most of the gate run now being a twisted pair, a 'balanced line'. I repaired it and moved the gate wires farther away.

   Additionally, the hesitancy of the motor to start is obviously a separate controller problem that needs addressing. I've run into it before. It's caused by the capacitors of the floating high side gate drivers discharging in less than a second in the phase being driven high if the motor doesn't quickly get turning. Once it's going they get recharged as the motor turns. I switched from .5uF to 2uF ceramic capacitors. It doesn't seem to have done the trick. And the higher the power, the faster they discharge, so 'giving it the boot' doesn't seem to help much.

New type of motor modulation control

   I started to think of going back to something I did with the motor controller that moved the Tercel with direct drive in 2008: pulsing the controller on and off at a few hertz until it reaches some set RPM, then allow normal control. The charge pumps will get reset in the 'off' periods, and the highest currents at very low RPMs won't be continuous.
   Reviewing the videos, I noticed also that the motor seemed wimpy under load. Then I divined the cause. "CRM" modulation - "direct torque control" - is much more prone than "PWM" to letting the motor stall under load, since the torque doesn't automatically increase as the speed drops. Once the motor starts slowing down, it keeps doing so and rapidly comes to a stop unless you're very fast to "hit the gas". This in fact seemed to be the main reason the results weren't better in trying to move the car.
   This suggested making a combined control: Use the CRM, perhaps always at "full throttle", and modulate that with low frequency PWM. The CRM will come back on after the short fixed off period, so the PWM can be as slow as desired, even 20, 10 or 5 Hz, without loss of power. Switching transients and losses (= controller heat) are still minimized with the low PWM frequency. Hopefully the PWM "off" period will allow the charge pumps to recharge and eliminate the low starting torque problem. I suspect the combined control will probably make the best system ever. 4-1/2 years later, I'm still finding better ways to do things that most makers think are already optimized, 'standard practice'... and then having to redesign my circuit boards yet again!
   But I can try out the system with an external single chip PWM generator tied into the 'electron pedal' in the car, sending a pulsed 'max. throttle' setting to the CRM controller.

   If everything works well in the controller, motor, and converter, it seems to me the 4 to 1 chain reduction could be reduced, even to 1 to 1. That would allow the Sprint to do 100+ Km/Hr without over-revving the motor, if it can get going that fast.



Planetary Gear Torque Converter Project

   The first converter tests are covered above as a component of the total system in the Sprint car.

3D-Printed Plastic Planetary Gears?

   At the end of July (28th) I went to the Victoria Maker Fair. I was mostly interested in the 3D printing, and I got the names of some software and a person or two doing home 3D printing in Victoria. Among the displays was a planetary gear with straight teeth, about 2" wide and 5" in diameter. The parts seemed huge compared to their metal counterparts. I was about what I had envisioned to replace metal gears with, to spread the loads over large areas and to avoid needing an oil drip. Would such a construction stand up to automotive stresses?  (If 2" wasn't enough, maybe 3", or 4"?) I was told its ratio was about 5 to 1. I should have got the name of the person who made it (who wasn't the person at the table). Maybe the design is on line somewhere.
   I think my ideal would actually be aluminum sun and ring gears and a steel planet gears assembly with plastic planet gears - probably of the higher temperature nylon-like plastic whose name escapes me at the moment. With the slight porosity of printed plastic parts, the plastic gears could hold lubrication and some grease should do for lubrication. I doubt I'd find 2 or 3" wide, large diameter aluminum planetary gears, and that's too wide for abrasive waterjet to cut, so it would probably devolve down to a nasty machining job needing fairly special CNC & cutting tools. If printed plastic for all the gears works, it'll be the simple choice.

   Furthermore, for under hood conversions, a plastic part could easily be printed as a ring gear on the inside and toothed belt pulley on the outside, to drive a similar toothed pulley at the differential. This would make the torque converter/transmission unit very compact.



Solar Electricity Project

Price is already there some places...

   A couple I know bought a half finished cabin in Hawaii (Oahu?). Evidently the price of electricity there is already 40¢/KWH, and it gets a lot of sun year round. Payback on a solar system might be 3-5 years. This would already be a good place to market solar system, LED lighting and refrigeration equipment... for which I have concepts but not as yet products.

Super battery Stick not so Super

   I hooked my 70 cell "Super Battery Stick" in the 4" PCV pipe, with 7 rows of D cells in parallel, into the solar collector system. I thought it should run the 4 amp fridge all night. Instead, it was crapping out after 4 hours. I shook it and the voltage went up. Of those 7 rows, how many were actually making reliable contact? And there was no way to test individual rows.
   I decided that the "Super Battery Stick" idea wasn't really a very good one. Individual pipes of 10 cells can be tested individually and proper operation of each ascertained.

   However, another factor to be considered was voltage drop. Voltage started at 13.8 out of the DC to DC converter from the collectors, but through the alligator clip wires it became 13.4 at the battery (thus it didn't stay at full charge even during the day) and 13.1 at the plug of the fridge unit. And, since I was measuring... the long, thin cord supplied with the cooler lost another whole volt to 12.1 before it hit the circuit. The moral of this is to put the batteries close to the charge controller with short, fat wires, and to keep all wires thick enough.

   Additionally, I have the idea to make compact plastic 10 cell/12 volt D cell battery holders using the 3D printer. These are likely to be the most practical general solution, at least where 26 or 14 inches length of space isn't available for the long 12v or 6v sticks.



Superinsulated Thermoelectric Fridge & Freezer

   Single Peltier Cooler Again

   On looking over the datasheets, I decided the two-stage cooler didn't really look any better than the single stage. The heating of the warm side element by the cool side element essentially seemed to cancel out the benefits at refrigerator temperatures.
   So I tried the same arrangement as had given me freezing temperatures but with the single original peltier, and got better results: it hit -13ºc. With the heatsink attached but no fan, it still managed to hit freezing in  a warm room. (or even -2, depending on the orientation (& hence airflow) of the heatsink.) Keeping the warm side a few degrees cooler would also cool the cool side a bit, but the desired temperatures were in fact attainable by the unit itself as made.
   At the flip of a switch, the cooler unit could become a warmer. That didn't seem very useful at first, but it defrosts the cold side heatsink in minutes, before the fridge itself warms much. A rectangular 'funnel' under the inside heatsink would carry out the drips through a plastic hose. I was wondering if 'defrost' should be left as a manual operation, or if the temperature control should have it built in. Then I put it on defrost and forgot it a couple of times, and the fridge was warming instead of cooling. Now I'm sure it should be automatic!
   The funnel might well be a custom 3D printed plastic part.
   It also occurred to me that the unit should shut off, or at least the inside fan should shut off, when the lid is opened, to avoid blowing the cool air out.

   Evidently I had been wasting my time with the double peltier. Logically then the fridge should just need more watts, eg, two cooling units... but I still suspected a problem in the cooling unit, perhaps in its layout, because it attained about the same temperature, 8 to 10ºc, no matter how much insulation I added to the fridge, or even back on its original cooler. Why was it hitting a "wall" at that temperature? A second identical unit would double the watts, but might get it little cooler.
   So I wasn't quite ready to give up. About the only thing I could think of to try was to separate the warm and cold sides more, to place them entirely outside and inside the thick insulation of the fridge, by putting in a longer block of aluminum through from the peltier to the inner heatsink. (If I'd known I was going to do this, the fridge would have just needed a small square hole through the insulation instead of a giant one to mount the whole original unit as it was.) Copper transfers heat even better, but it's both costly and heavy. If there was much temperature rise along the length, a fatter piece of aluminum is probably a better answer. (Seemed pretty good.)

   I added a couple of chunks of aluminum and extended it over 2", but the fridge insulation is over 3" so the inside was still well recessed into the wall. Without a fan, the cool side heatsink went to -6 and the fridge to about 12 (seemingly somewhat stratified - cooler at the floor below the unit than up at the lid). With a fan, the heatsink rose to +5 but the fridge stayed at 12, less stratified. With the peltier cold side 10º warmer, it should have been delivering notably more cooling. It was still hitting that "wall" where it simply didn't want to further cool the space, for no readily apparent reason.
   It would need about an added 2.5" to 3" block of ~42mm x ~44mm aluminum to have the inner heatsink sticking out in the inner space. The next morning I was passing a recycling place. I stopped and found a 3/4" thick slab. I cut a piece to fit. With no fan, the inside heatsink, now exposed properly to the inside air - vertical with the fins up-down, hovered at about zero. It seemed to reduce or eliminate the need for an inside fan, but the fridge space didn't get any colder.

   I finally concluded the obvious, that the unit simply didn't have enough watts of cooling power to attain the desired temperature in the space being cooled. That means the unit will inevitably run all the time, and a temperature control is virtually superfluous. I also finally realized that a temperature reduction on the warm side doesn't mean an equal reduction on the cold side, just a few more cooling watts. A bigger heatsink, stronger fan, or water cooling of the warm side just might make 1-3º difference inside, but it would be the 'law of diminishing returns', much effort for a small gain.
   Of course, the lowest temperatures already attained, 8 to 10º, are much better for food storage than room temperatures. Some might even say "Good enough for me." (Someone wrote that 3-5º is optimum where I thought 2-4º... one less degree to cool to) In the winter in my cool kitchen it would get lower. I decided I'd consider 6-7º or under (with a 23º room temperature) to be essentially food worthy.
   I decided to replace the peltier in the cooler with the highest power 18$ peltier element available at Digikey, tho it's only incrementally higher power than the original. It might just make it 2 or 3 degrees cooler without needing more hardware - heatsink and fan units. If that didn't hit 6º, a bigger heatsink on the outside might just make the remaining difference. But a new plan (below) came to light before I got to ordering it.

   Meanwhile, although it was too late to shape the fridge for minimum exterior surfaces per volume, eg, as an octagon shape with shorter walls and a terraced saucer floor (so that tall objects could fit in the middle and shorter ones around the edge), I put some wedges of foam in the corners (making a slight octagon of the inside).
   It also occurred to me I might still shorten the walls a bit and make a domed lid, or a lid with less insulation inside in the middle for tall objects, in lieu of the saucer floor. (The almost flat floor is done. I could take a jigsaw to it - ugh!) Every inch of shortening of the walls is 3/4 of a square foot less surface to cool. (Rectangular interior surface area of 18" x 36" x 12" walls is 18 square feet.)
   I suppose the ultimate shape to minimize the exterior surfaces of an object with flat sides, would be a geodesic dome.

   Considering it gets close to fridge temperatures, such little things as minimizing surface per volume, sealing the lid, and putting on the outer skin, should make notable differences to the temperatures attained with the same tiny cooling unit. There's another possible expedient...

Fridge Size Experiments - & without inside fan

   It occurred to me on the 16th to cut and insert a piece of 2" styrofoam to divide the space. Thus I obtained a variable size refrigerator. With a room temperature of 25-26ºc (scorching heat for my house), the whole fridge (with the cooling unit reconfigured to go through the 3" of insulation, but no proper duct over the cold side fan and heatsink) was attaining 13-14º. Divided in half, the cooled side reached 17º while the virtually uncooled side settled to 19-20. Huh? Something was definitely rotten in the state of Denmark. I found a rusty alligator clip wasn't making connection from the converter to the battery. The 30 AH battery, having delivered about 5 amps for nearly 5 hours, was down to 3 volts. That was serious overdischarge, even for NiMH, and it certainly explained the poor cooling performance. Probably on reconnecting the low battery, I found the "25 amp" fuse from the solar collectors to the DC to DC converter was actually 7.5 amps and was (understandably) blown.
   I waited for the current (charging the battery) to drop below about 6 amps and tried again, making a note to replace the rusty clip that evening. This time it reached 11, still with the uncooled side about 19. (The outer heatsink read 40º. The inner one was 7º, but the peltier was 1 to 2º, showing poor thermal coupling from the element to its inner heatsink.) Cooling only 1/4 of the space, the temperature hit 9 -- a 16º cooling. It wasn't a whole lot cooler than 13 considering it was 1/4 the space, but it probably shows the physics: the higher the temperature difference, the harder it is to attain and maintain.
   Later (20th) I tried without the inside fan. Evidently there are more air leaks than I thought or something, because it worked better instead of worse. Cooling about 1/3 of the fridge, temperature was 3 in a 22º room. The 19º was the largest temperature differential attained. A still smaller space hit 2º. The inner heatsink, at -7º, was heavily frosted up after a few hours. Obviously either the heatsink should be enlarged or the fan is needed. I'll probably make a small ice compartment right around the cooling unit.
   I turned the setting to "heat" and again defrosted and dried the cooler in 5 minutes - what a great defrost unit! The tray beneath collected about a tablespoon of water.

   A little later I found that the temperatures were considerably higher near the top than near the floor of the unit, the temperature stratifying. Either the cooling unit should be at or just below the lid instead of mid wall height, or the inside fan is needed to circulate the air.

   By the expedient of making the fridge smaller with an inside wall, a certain amount of food can be kept cold even on warm days, while in the winter the whole space will be available if needed. On the other hand, around 38 KWH a month (since it runs all the time, so far) was as much juice as a good energy star full size fridge to cool around 1/3 to 1/6 of the space. That's about a whole solar collector's worth and more in the summer, and unless it shut off part time it probably couldn't be powered continuously all winter.

   Well, I can't say I wasn't warned Peltier cooling wasn't very efficient. Coefficient of performance is typically .3 to .6 (Wikipedia), or around 1/2 watt of cooling for every watt of electricity used. A compressor based fridge, or a heat pump, might be 1 to 1.5. A home heating heat pump might be only one at sub freezing temperatures, but the electricity used is also heat, so one becomes two for heating but not for cooling.

Magnetic Refrigeration

   But it does cool, and... "Seek and you shall find." - and not always what you expect to find (or you'd have already found it). Soon after the July newsletter someone sent me a Wikipedia link to magnetic refrigeration, which I hadn't heard of. The potential coefficient of performance is perhaps 5 or higher! Seemingly in accordance with my 'thermomagnetism' theory, some substances heat notably when exposed to a strong magnetic field, and similarly cool when removed from the field - The "magnetocaloric effect" (MCE). If they're cooled back to room temperature with a heatsink while within the field, they get notably cooler when the field is removed. The fields employed are in the range of 1 to 7 teslas. 1 or 2 is attainable with supermagnets. Potentially there are a number of ways the heat could be transferred from the fridge to a heatsink via the substance being heated and cooled.
  Development is in experimental stage and it looks very promising. The most promising research cited is in my own town, Victoria BC. A 2009 paper said it was potentially more efficient than compressor + gas refrigerant refrigeration: 30-60% of theoretical carnot cycle, versus 5-10%. And it uses one of my favorite things: magnetism! The best substances (which change magnetic state) at about room temperature include gadolinium (Currie point 293ºK), alone or in an alloy with europium (I think the document is in error - it seems it's erbium, not europium. Currie point 278ºK).

   How complicated would it be to do well? I decided to try and contact the researchers and look into their latest system and ideas. Peltier was the only viable refrigeration idea I initially found, but it's not very efficient per se and I'm not wedded to it. I'll jump horses in midstream at the drop of a hat like a scared rabbit rather than throw good money after bad if there's some other bandwagon I can put before the horse - if it proves reasonably simple to do. After all, much of my effort went into building the enclosure. That can be cooled any practical way that can be found. Perhaps adequate cooling can be accomplished with fewer watts instead of more, by building on the UVic research?
   An 'autoreply' said the chief researcher was away. He didn't respond to my e-mail when he was supposed to have returned. Then I noticed he had started a company looking for funding to commercialize his complex designs. By that time, I had read a paper surveying existing designs, worked out my own simpler idea, and ordered gadolinium.

   If the performance is good, perhaps really efficient small scale heat pumps and air conditioners can also be made without typical compressors and refrigerant gasses. If a practical unit can be produced, the potential for small size, lower energy heating and air conditioning units is enormous. The peltier heat pump might do 1.3 times better than a regular electric heater - significant but not Earth shattering. And it wouldn't make an effective air conditioner. Something that could provide two to five times the heat per watt of an electric heater, in a small plug-in size unit (and maybe cooling too), would be a real game changer. Decentralized, individual room furnace replacement units using maybe 300-700 watts instead of 1500 would be worth putting a hole through the wall for!
   But, even if it's practical and much better than peltier: is it worth it for me to get involved in developing it? I only started out to make a refrigerator that would work with a low voltage DC solar power system. On the other hand, my winter electric bills are high, and lots of people pay much more than me. To cut heating bills in half, or by 2/3 or 4/5, is potential to drool over.
   I decided to order some Gd. I saw it for about 1.0-1.5 $/gram in 100 gram lots on e-bay, then I phoned HEFA Rare Earth in Richmond BC: 490$/Kg or 54¢/g for smaller amounts. Then: So an alloy of Gd:Er might be tailored to a specific Curie point? What about one with a low point (erbium?) alloyed to one with a high point (iron, nickel...?) in varying proportions? I ordered some erbium too (35¢/g), but I'm not sure how I'll accomplish any alloying without oxidizing any rare earths.

Gleaned from Literature

   I read a 32 page paper that was a survey of all magnetic refrigeration experiments and prototypes prior to 2010, including th eUVic ones. (wenku.baidu.com/view/8dd4353410661ed9ad51f3f8.html###)

   Evidently an alloy of Ni:Mn:Sn has a reverse magnetocaloric effect: it cools on entering a magnetic field, and warms again as it exits it. Some alloys (eg, Gd:Si:Ge) have a "giant magnetocaloric effect".

Curie temperatures:

Gd - 100% - Curie = 293 K (20ºC)
Gd:Tb - 74:26 % - 285 K ??
Gd:Er - 85:15 % - 278 K (5ºC)
La:Fe:CoSiB - Bal:10.97:.78:1.05:.2 % ??
Ni:Mn:Ga ??

    About 50 watts of cooling power is supposed to be sufficient for a typical refrigerator. (In which case why can't I cool the superinsulated fridge with around 20 watts?)

Typical magnetic field strengths were .9 to 2 teslas, with a few superconducting electromagnets supplying up to 7 teslas.

Typical cooling cycles were around .2 to 4 Hz, mostly under about 1 Hz. The gadolinium needs time to magnetize and time to transfer the heat. (Thinner pieces at a higher frequency of operation should pump the same amount of heat while requiring less gadolinium.)

   There were heat conducting fluids employed including helium, water, air, pH 10 'basified' water, and olive oil, but in 41 prototypes described, none used solid state heat transfer. Personally, I suspect that the first researchers used a gas or fluid, and while varying much else, the rest have just copied that. But solid contact between flat copper or aluminum faces is surely the fastest way to transfer heat, and the fact that gadolinium is attracted to the magnets provides a very convenient means for shuffling it back and forth between cold and hot sinks at (surely) just the right times. (If a MCE alloy isn't heavy enough to make good thermal contact with the lower heatsink, perhaps a bottom facing of copper foil could add weight.)
   Furthermore, the report states that while the promise is there for 20-30% efficiency improvement over compressor/gas systems, substantially higher performance is being prevented by the pressures needed to overcome friction and drive the fluid or gas sufficiently through the system. Such extraneous power demands are largely eliminated in the solid state system, so it *should* prove far more efficient. If I get 1.5 times what compressor & gas refrigeration gets, it'll be an advance over the fluid systems. Double would be even better.

Gd & Magnetic Motion Machines

   I also wonder if there's some role for gadolinium in ambient temperature powered magnet machines? Surely the heat and the motive force are reciprocal forces.
   Related to this, I found the following video, where a paperclip hanging from a metal "string" is attracted to a magnet, which lures it into a candle flame. The flame heats it up to the curie point of the steel, at which point it loses its magnetism and falls back. Soon it cools off until it's attracted to the magnet again, and the process repeats itself repeatedly until it becomes repetitive.
   The curie temperature, BTW, is also the point iron has to be heated to in order to anneal or harden it.

fueloptimisers.com/magnetic-heat-engine-curie-effect.html

"Curie Point Magnetic Heat Engine
How it works

   The heat engine uses a principle of magnetism discovered by Pierre Curie. He studied the effects of temperature on magnetism. Ferromagnetism covers the field of normal magnetism that people typically associate with magnets. All normal magnets and the materials that are attracted to magnets are ferromagnetic materials. Pierre Curie discovered that ferromagnetic materials have a critical temperature at which the material loses its ferromagnetic behavior. This is known as its Curie Point. As an example, a piece of iron (Fe) at room temperature is strongly attracted to a magnet. Heat the iron to a temperature of 770 C, which is its Curie Point, it loses its ferromagnetism behavior and it is no longer attracted to a magnet. If we let the iron cool, it regains its ferromagnetic behavior and is attracted to the magnet again."

   This was hardly a perpetual motion machine. The energy of the paperclip going back and forth was minute compared to that of the candle flame. But the curie temperature of iron is 770ºc. Even slight heating and cooling would put gadolinium above and below its room temperature curie point, but the magnetism doesn't seem to change as far as I could feel.

My Plan for a Magnetic Cooling Unit

I came up with an idea for a cooling unit that uses solid parts only, no gas or fluid:

A rotating disk of supermagnets would pull on 2 or 3 stacks of gadolinium wafers (each faced with epoxied copper foil to protect the reactive gadolinium from air and moisture), interleaved with aluminum or copper heatsinks. Each stack of wafers would "shiver" up and down as the magnets passed, heating as the magnet approaches while being pulled up to the upper, warming heatsinks, then cooling after the magnets pass while the stack drops back to the lower heatsinks, pumping heat through the stack from bottom to top. Each individual wafer cools by 2 or 3 degrees.

   In my first plan, the (epoxied, copper foil faced) gadolinium wafer stacks would have been be held together by a framework along two opposite edges. The interleaved copper heatsink pieces would be framed along the other two edges, creating two interleaved stacks.
   On the 24th I came up with the idea of framing the copper heatsinks on all four sides, which would simply trap each loose gadolinium wafer in a thin box between two heatsink pieces. Nothing would hinder the wafers from jumping up when the magnet arrived and falling back afterwards, and making good, square contact with both the heatsink above and the one below. They only need to go up and down a fraction of a millimeter - good square contact - very flat surfaces - is the key.

   Naturally I thought of making the stack frames of plastic with the 3D printer, but for a prototype that would probably just be a luxury. They could just as easily be glued up from sheet plastic. If each gadolinium wafer can be in a tiny sealed compartment with minimal retained air and moisture, it shouldn't be necessary to epoxy them and face them with copper foil, simplifying everything, shortening the stacks, and maximizing heat transfer.

   The reason for multiple stacks is to attempt to balance the magnetic forces acting on the motor's rotation, so as one magnet is approaching and being pulled towards a stack, another is leaving a stack and being pulled backwards. It'll also be necessary to put stacks thermally in series to get sufficient difference between hot and cold ends while keeping the stacks short to keep the gadolinium wafers close enough to the magnets.

Recap:
* A rotating disk of supermagnets (should provide sufficient magnetism, but stronger is probably better).
* A stack of copper plates (Cu sheet metal heatsinks) with narrow spaces in between them, sealed around the edges to protect the Gd from air and moisture.
* Each space is loosely filled by a wafer of gadolinium. (Even Gd dust would work, but single flat pieces will transfer heat best.)
* There may be two or more such stacks, with copper or aluminum connecting the cold side of one to the hot side of the other, to double the number of cooling units in series. (Since the wafers all have to be as close as possible to the magnets, the stacks will be at most an inch long.)
* An outside/hot side heatsink with fins and (probably) a fan. (must be thin at the end to allow magnet rotor to pass closely to stack - fins aim the other way.)
* An inside/cold side heatsink (large or with fan) inside the fridge.

   That seems quite simple and straightforward - in fact, much simpler than gas refrigeration.
   One likely complication, especially for production, is how to form the gadolinium ingots/chunks into sheets. I'll fudge a few some way for test prototypes. Even gadolinium powder or filings should essentially work, tho not transfer heat as fast as a solid sheet. If it needs to be heated, it would have to be done in an inert atmosphere, and Gd's melting point, 1312ºC/2394ºF, is at the extreme limit of my kiln temperatures. (I wonder if one can create a sealed steel box and, say, keep argon flowing through it while heated to high temperature? It seems welding places do have tanks of argon - 200$.)

   Considering the incredible potential benefits, I can hardly see walking away from it. (Sigh!) The project is On!

Chest Freezer As Refrigerator

   Someone wrote of a chest freezer being used as a refrigerator for off-grid use. This seems like a brilliant idea! A unit designed to cool to -10c naturally cools to fridge temperatures very easily and stays there longer. (If it isn't super energy efficient to start with, putting a couple or 4 inches of foam in the bottom and on the lid as I did with my freezer should help considerably.)

   Energy use is evidently minimal and the owner is quite pleased with it. I might try it myself except instead I want to try the magnetic cooling, which should be even better.



Turquoise Battery Project

   The battery project, LED lighting project, and aspects of other projects came down to assembling the 3D printer kit, with which device I plan to make various battery parts, LED light bases, and PCB artwork. I did 3 hour sessions on several days or evenings, and assembled the frame, "Y" axis carriage, "X" axis carriage, heated printing surface, hot plastic extruder head, ...


   About the only other things that happened were the arrival of the osmium ordered last month, and some samarium oxide - in an order with some rare earth metals for magnetic refrigeration experiments. Sm2O3 should be a bit better trace additive for raising oxygen overvoltage than Nd2O3, which I have about a pound of, so it wasn't exactly a critical purchase. But here was the time and place to get the best.
   The osmium is indeed dense. The 10 gram blob of bluish metal is only 1/2 a cc in size, like a fat shirt button. A kilogram would be just 45mL. But there's no way one could afford a kilogram of it, cool tho it would be to feel its heft.



http://www.TurquoiseEnergy.com
Victoria BC