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For Steve Stewart ...
It may take a while before we have something in the propulsion space that Dr. Johnson is willing to endorse.
Meanwhile, ** many ** thanks for your Introduction to Thermodynamics !!! What a terrific addition to the forum archive!
Rather than having me intrude upon your flow, please consider adding a tag to your piece in the form:
s e a r c h t e r m (colon) t h e r m o d y n a m i c s
We know that method works in this forum. When combined with the author's name, it should produce a single post when invoked.
As usual to avoid unwanted search results, I have shown the search expression with spaces.
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For Steve Stewart!
Thank you very much for preparing the Tables of Contents of the YouTube recordings of the 2023 Mars Society Convention streaming events.
I am looking forward to a leisurely sampling of all that bounty, in weeks and months ahead.
Thanks too, for offering to assist RobertDyck ... The drawings you are able to provide would fit nicely into an eBook, which RobertDyck could populate with text. One detail that may be new to some members of the forum. When you prepare your images for RobertDyck to add to his eBook, it is helpful if you can deliver them in .SVG format. This allows the eBook reader to change the size of the images to fit the format of the device upon which they are rendered. This adds greatly to the enjoyable experience for the customer. I'd suggest a retail price of 99 cents on Amazon, of which
Amazon will take 50 cents. The idea is not to make RobertDyck wealthy, but instead to reach as wide an audience as possible. However, even in Canada, 50 cent pieces add up.
Who knows? RobertDyck might even share a portion of that 50 cent piece with those who contribute to the eBook.
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Steve re post #15,
New equipment is expensive and usually not what you want to do. In 2009 my clothes dryer failed. I had difficulty finding someone who knows how to repair appliances. They usually said "that model isn't made anymore, we can't get parts". But I asked them to repair, not replace. Eventually I found a company that was competent. The technician found the bearing for the blower seized. He removed the blower, toolkit to his shop. There he removed the bearing and took it to a company that specializes in bearings. It was repacked. He then reassembled the blower, after cleaning out lint. Then brought it back to reinstall. The V-belt broke, so he replaced that too. It was a natural gas dryer, every technician said the points for the igniter would be worn. But they all checked and found its in very good condition. My dryer came with the house, it's older than I am. The dryer was manufactured in 1961. It was 48 years old when it needed work and will last at least another 25 years. New stuff is crap.
A few years ago the motor for the blower of my furnace failed. I found a plaque on the motor with specs, found a company that specializes in motors, and replaced it myself.
A few years later the furnace failed again. The nature gas utility used to provide basic repairs for cost of parts. The electric utility bought them, so I called. A technician checked and found the gas valve failed, basically cooked. He replaced it. Then he found a crack in the heat exchanger. The draft caused flame to roll back into the valve box. So he shut off the gas, told me I had to find a heating contractor. I called several, most refused to touch it. One sent a technician, be he refused to repair, said I *HAD* to replace it. He only sells high efficiency furnaces, which are not only expensive, but required punching a hold in the basement wall for for air intake and exhaust. And required a water drain line. I escorted him out.
Remembering what the appliance guy did with the dryer. I opened the furnace myself and removed the heat exchanger. It's *BLEEPING* heavy! Made of mild steel. I had a friend help me carry it out of the basement. That same friend used his pickup truck to carry it to a welder that I found. I asked the welder to seal the crack. I also asked him to inspect for other cracks, or weak spots that will crack soon. He didn't find any new cracks, but said the welds from manufacturing that held the sheet metal together will fail eventually, so welded a heavy weld over them. Brought it back, reinstalled myself. Asked the natural gas utility no send someone to turn the gas back on. They said my heating contractor should know how to do that. The previous natural gas tech had used a crescent wrench to turn a valve 90° so I just turned it back. Checked for air leak using a lighter: it was fine. Adjusted the flame for maximum blue colour. That means maximum combustion, so most efficient and least carbon monoxide. Check everything then turned the gas off again. Called the natural gas utility to send an inspector. He checked with a carbon monoxide sensor, found everything was done right. Then I told him what I did, that I was my own heating contractor. His eyes went wide, then he checked everything again. And again. And again. It was all done right so he certified it safe.
Oh, I didn't mention. Before reassembling the furnace, I thoroughly cleaned everything. So my furnace had a deep cleaning.
My dad was not only a big do-it-yourselfer, he was a professional construction worker before he got married. He then got a job as a welder with the heavy equipment shop of the railroad. So he ingrained in me that a homeowner is supposed to do this stuff himself. But he was a pro, not just an amateur. So I have a high standard I'm trying to live up to. I'm not as good as dad, but I try.
My natural gas furnace was also manufactured in 1961. It's not high efficiency, but to call it robust is an understatement. They knew how to make things last back then.
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Rob(#28),
Wow that's an interesting story. You're so right about things being built better a long time ago than they are today.
Several years ago I remember seeing an episode on "Jay Leno's Garage" about an old steam engine. As I remember, the steam engine was built in the 1800's and was used for the textile industry somewhere in Europe. (This was the beginning of the industrial revolution). Jay Leno stated that Henry Ford had bought the steam engine because it was an antique, and he wanted the engine for his museum (The Henry Ford Museum).
I'm listening to Jay talk while doing some math in my head. I knew that Henry Ford had started three car companies. What we know today as the "Ford Motor Company" was the third car company Henry Ford had started. I believe Henry Ford was in his 40's when he left the second company he founded and sometime later got funding to make a third attempt at starting a car company. Later Ford made several car models before the Model T, and it took a number of years before the Model T was in high production.
So if Henry Ford bought this steam engine after he became wealthy, and after he had already established a museum, he probably would have bought that engine sometime in the 1920's (I'm guessing). Jay Leno then purchased the steam engine from the Henry Ford Museum. Jay stated the engine had ran for about 80 years if I recall correctly. The textile factory then replaced it. Not because it was worn out, but because it had become obsolete, it was too small -- not powerful enough.
So if the engine had ran for about 80 years, then was replaced, then was laying around for who knows how many years, then was bought by Henry Ford in the 1920s because it was an "antique" by that time. I want to know something, when was this engine made? It was probably made in the mid to early 1800s would be my guess. So how is it, that mankind was able to build a steam engine in the early 1800s, that was used most everyday for 80 years and is still running to this day, and yet today we can't buy a new kitchen appliance that will last 10 years?
I think the answer is planned obsolescence.
I remember running across some old posts where you talked about this, and I agree we need to talk about this on Mars. I think on Mars we need to utilize "standardization", meaning that parts from one piece of equipment needs to fit on other (different) pieces of equipment. I should probably write a paper about that sometime. I have a lot of ideas on that subject I'd like to share (some other time).
Here is an example:
A couple years ago in the summer of 2021 I paid a visit to the Seelye Mansion in Abilene Kansas. (The mansion is open to the public for anyone willing to buy tickets. There's a lot to see in Abilene). While on tour they pointed to the light fixtures in each room. Some of the fixtures were designed by Thomas Edison himself, as he had visited the mansion a few times. The lights were still on after over a century of use. Some of the lights had burned out over the years, and they keep them on display in a vase because the lights are an antique. Below is a picture I took of the few Edison lights that had finally burned out.
This is why we can't have nice things
YouTube video 17m 29s
Article: Planned obsolescence and its environmental impact
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Do I need to eat my words? Came home from convention to a cold house. Checked windows, all closed. So checked the thermostat. Setting 72°F, but thermometer on the thermostat reads 56°F. Weather website says it's currently 5°C (41°F) outside. I checked the furnace: pilot light was out. Was able to re-light the pilot light. Furnace is now running. House will be warm soon.
Was warm when I left for the convention; I didn't bring a jacket. Well, a suit jacket. Fall weather when I got back. At the airport in Winnipeg I put on a long-sleeve shirt over my golf shirt, and my suit jacket.
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Rob(#30)
No I don't think you need to eat any words. If your furnace wasn't running when you were gone it means you saved money on gas. Good thing it fired right up when you got home. Just think what would happen if you were on Mars and lost heat. That's why we need redundancy for everything on Mars. Maybe double redundancy.
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For Steve Stewart re Saturday Video index...
Thank you for adding this new index to your series!
I decided to print the convention schedule and see how many presentations I can catch in the weeks ahead, using your index as a guide.
I already saw the talk about China that was given on Saturday because it was up on YouTube when I went looking. I wrote a short comment on the talk, which I thought was well done.
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For Steve Stewart re nice addition to Shopping topic ...
http://newmars.com/forums/viewtopic.php … 02#p216102
The cat looks contented !!!
The hail storm damage is a hazard that might not have occurred to me, if I had plans to build/install a greenhouse like the one you showed us.
One possible remedy is to provide a hail-proof snow-proof rolling roof to deploy over the glass when there is a threat, or at night when the cover might decrease heat loss. That ** is ** an additional expense, but on the other hand, the rolling roof could provide a shady work area when it is not in use for protection.
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For Steve Stewart re complete list of Stanley YouTube videos
Thanks for this very nice addition to the Greg Stanley topic!
As a likely preview for next month's report of Space News, I expect Dr. Stanley will have collected everything available about the most recent Starship test.
The exact nature of the failure of the booster will be of intense interest, and the perplexing failure of the Starship itself will be of equal interest.
Since Hot Staging has never been attempted before with a reusable vehicle, let alone one ** this ** large, it is understandable there are technical challenges to be worked through.
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