Last Man Posting

For all your forum game goodness!

Moderator: Moderators

Message
Author
User avatar
Bellhead
Templar Inner Circle
Posts: 4012
Joined: Wed Oct 23, 2013 11:17 pm
Location: New England, US
Fav. Twokinds Character: Keith and Natani

Re: Last Man Posting

#14851 Post by Bellhead »

Believe it or not, back in college, I had this chemistry professor.. Can't remember his name. But out of a class of something like 25 people, only a select few could stay awake the whole class. Had this voice that just put you to sleep, no matter what he said. He would make these online study videos for us to watch, and I used to use them as a lullaby. It was that bad. I literally couldn't keep my head up.

Heh.. One day I did put forth a legitimate effort, took notes, followed in the book, payed full attention.. Then I blinked and he was writing in Greek. I kid you not.
Gearhead mechanic in the digital era, who will probably grow up is in the process of growing up to be a very grumpy old man.

User avatar
Technic[Bot]
Grand Templar
Posts: 1246
Joined: Sat Jan 27, 2018 9:48 pm
Location: México
Fav. Twokinds Character: Raine!
Contact:

Re: Last Man Posting

#14852 Post by Technic[Bot] »

Generally the one writing Greek are physics professors not chemist.

Anyhow i also had this professor on college, linear algebra. I don't think I ever managed to stay awake for the full class. Which was curious i actually liked that class, was ones of my favorites in college i even managed to get straight As* on that class. Yet I never managed stay awake. His voice always put me to sleep or maybe my sleep schedule was just that bad

* Not sure it is the correct expression grading scale over here is numeric.
There are three things that motivate people: Money, fear and love.
Links to my ramblings:
Twokinds [of] data
PhpBB in the age of facebook
If you are new to this phpBB thing:
BBCode guide

User avatar
Bellhead
Templar Inner Circle
Posts: 4012
Joined: Wed Oct 23, 2013 11:17 pm
Location: New England, US
Fav. Twokinds Character: Keith and Natani

Re: Last Man Posting

#14853 Post by Bellhead »

Grading here is numeric as well. 70-80 is a C-, C or C+, as it is 80-90 for B, and 90-100 for A. I've usually seen it written as A's or 'A's, rather than As, but your meaning got across fine.

That said, the symbols he drew were Lambda and Nu, if I recall. Something to do with the resonant frequency of atoms needing to mesh properly to create a chemical bond that results in specific molecular shape and bonding properties... They basically made us learn molecular geometry, before I could learn how to use the CAD program I pirated. It made no sense to me, still doesn't.

Turns out that being good with your hands makes you able to build things, and thus design them, while knowing what material to make them out of just makes them harder and more expensive to produce. So that was probably it. I could do with a block of wood and a roll of duct tape what a room full of college students couldn't do with CAD, 3D printing and digital simulations.
Gearhead mechanic in the digital era, who will probably grow up is in the process of growing up to be a very grumpy old man.

User avatar
Tornir
Master
Posts: 343
Joined: Thu Jul 08, 2021 8:29 am
Fav. Twokinds Character: Maeve

Re: Last Man Posting

#14854 Post by Tornir »

Today is :flora: International Tiger Day :flora:
Celebrating Flora's everywhere.

User avatar
Bellhead
Templar Inner Circle
Posts: 4012
Joined: Wed Oct 23, 2013 11:17 pm
Location: New England, US
Fav. Twokinds Character: Keith and Natani

Re: Last Man Posting

#14855 Post by Bellhead »

All hail the orange floofs! :flora: :laura: :mike:
Gearhead mechanic in the digital era, who will probably grow up is in the process of growing up to be a very grumpy old man.

User avatar
Neutral Smith
Templar GrandMaster
Posts: 673
Joined: Mon Feb 24, 2014 5:32 pm
Location: Neitherlands
Fav. Twokinds Character: Saria's father
Contact:

Re: Last Man Posting

#14856 Post by Neutral Smith »

Did someone say celebrating orange?

phpBB [video]

(Dutch soccer fans)
If it moves but shouldn't: Duct tape. If it doesn't move but should: WD-40. With a hammer everything fits, and if it still doesn't fit: bigger hammer. If it can't be fixed with a hammer it's an electrical problem.

User avatar
Bellhead
Templar Inner Circle
Posts: 4012
Joined: Wed Oct 23, 2013 11:17 pm
Location: New England, US
Fav. Twokinds Character: Keith and Natani

Re: Last Man Posting

#14857 Post by Bellhead »

Image
Gearhead mechanic in the digital era, who will probably grow up is in the process of growing up to be a very grumpy old man.

User avatar
Technic[Bot]
Grand Templar
Posts: 1246
Joined: Sat Jan 27, 2018 9:48 pm
Location: México
Fav. Twokinds Character: Raine!
Contact:

Re: Last Man Posting

#14858 Post by Technic[Bot] »

Ther is indeed a day for everything. Happy tiger day I guess. 🐅

Spoiler! Some musings on molecular geometry
That sounds rather involved even for a college level chemistry class. We're you by any change a chemist major?*

For frequency you usually go omega for angular frequency and f for normal frequency. Yet every field of knowledge has its own nomenclature and I am no chemist. Lambda is used in so many contexts i am not even gonna try to guess.

Material science is actually a very interesting field Definetely not my cup of tea but it is important to know what to build stuff of else may nor resist required loads. There is just only so much you can do with geometry alone.

* Disclaimer i do not really understand American higher education system so please excuse me if i mess up the nomenclature
There are three things that motivate people: Money, fear and love.
Links to my ramblings:
Twokinds [of] data
PhpBB in the age of facebook
If you are new to this phpBB thing:
BBCode guide

User avatar
Bellhead
Templar Inner Circle
Posts: 4012
Joined: Wed Oct 23, 2013 11:17 pm
Location: New England, US
Fav. Twokinds Character: Keith and Natani

Re: Last Man Posting

#14859 Post by Bellhead »

I was an engineering major. In Chem 1, we had a book that studied material and chemical properties by first looking at the bonding characteristics of the atoms themselves, so that when you learned how they naturally formed bonds, you'd be able to deduce what would happen to any given compound in any given situation, rather than learning the reactions, then the reason behind them.

That said, just about everything I learned at that school was entirely theoretical, and almost nothing was actually practical. Case in point: The university decided to save money by having the students design the building for the new library. Several stories tall, logical floor plan, etc, but whoever got the task forgot it was a LIBRARY FULL OF HEAVY BOOKS. Last I heard, the floors were sagging due to lack of support.

That was something I learned in the real world, that school didn't give a damn about: All the theory in the world doesn't account for a real-life situation. University engineering graduates are trained to save money and cut corners in every way possible, but they lack the training and/or common sense to do so without inhibiting functionality. They never tell you to take into account what a real situation would be like, outside of a simulation. Planes must encounter turbulence, wind, birds and stress from cold and sudden gusts. Vehicles driven in New England will rot like a week-old turkey. Plastic weakens with use and age, and dirt, AND sunlight. Lightweight wind-powered vehicles will require less wind, but heavier winds will blow them away completely. Putting paint or other coating on a surface does NOT, in fact, change that material's base properties, and my personal favorite, rust swells when it forms, changing a snug fit that needs to move, into "these two parts will remain one part until they rot into dust", sometimes in a matter of weeks. Or less.

It's almost 10 PM local time, and I decided to rant. I apologize to anyone tired of my lack of sense at this time of night.
Gearhead mechanic in the digital era, who will probably grow up is in the process of growing up to be a very grumpy old man.

User avatar
Technic[Bot]
Grand Templar
Posts: 1246
Joined: Sat Jan 27, 2018 9:48 pm
Location: México
Fav. Twokinds Character: Raine!
Contact:

Re: Last Man Posting

#14860 Post by Technic[Bot] »

In my 7 years of engineering school i do not remember anyone ever teaching me how to save cost and cut corners. Would have been a nice skill to have honestly, the guys pushing for cost saving are usually the accountants and the upper managements who cannot tell apart a car from a computer and generally engineering pushes back because this may affect reliability or safety.
In any case as I mention before, you are correct, the engineer designing something may not be optimizing for end user, if he manages to save a couple million on a part redesign the change will be made screw the poor mechanics who will have to deal with that. On top of that I am of the understanding that in most of the developed work most cars are not repaired as insurances prefer to pay out a new car., but i digress.

Funny you mention simulations, one of my professors was an engineering who had been working as a mechanical engineer for most of the second half the 1900s and all of the 2000 once regaled us with this story:
When he started working of course everything was done by hand plans were drawn with pen and pencil and, all material testing was done with universal machines and physical samples. Then when some of his students graduated and became engineers on their own they realized they were nothing like that anymore only computers.
This contrary to what you may expect has proven to be for the better. Calculating the stress of a piece lacks a closed form solution but for the most trivial geometries. And computational simulation has grown leaps from the 80's to the point that you have almost the same precision than using real life prototypes at a fraction of the cost, this has led to savings on end user, as they can use more efficient geometries for example and in general allows people to do much more work in much less time than before. At this point if your simulation fails to capture your real test in 99% is because you made a mistake, which can and happens even without simulations.

A lot of engineer students do love to build stuff, myself included, but engineers rarely build stuff themselves,something they do tell you in college. An engineer usually designs something he provides plans and blueprints and then someone else is the one doing the building. The engineer has to know why he made the thing as he did but does not necessarily how to make them, thought most do, of course but just a fraction of them would be able to build it, yet with the advances on CNC these days.... Anyhow the other guy in charge of actually making the piece does not really has to understand the why, just the how.

Agghh this turned out way longer than intended sorry been a rough week...
There are three things that motivate people: Money, fear and love.
Links to my ramblings:
Twokinds [of] data
PhpBB in the age of facebook
If you are new to this phpBB thing:
BBCode guide

User avatar
Tornir
Master
Posts: 343
Joined: Thu Jul 08, 2021 8:29 am
Fav. Twokinds Character: Maeve

Re: Last Man Posting

#14861 Post by Tornir »

Technic[Bot] wrote: Sat Jul 31, 2021 1:34 am Would have been a nice skill to have honestly, the guys pushing for cost saving are usually the accountants and the upper managements who cannot tell apart a car from a computer and generally engineering pushes back because this may affect reliability or safety.
Which is why they prefer to interfere in manufacturing, after you guys have handed it off; removing "non-essential" safety features, or substituting sub-standard materials.
Here's a notorious example of a production FUBAR by the bean counters.

User avatar
Bellhead
Templar Inner Circle
Posts: 4012
Joined: Wed Oct 23, 2013 11:17 pm
Location: New England, US
Fav. Twokinds Character: Keith and Natani

Re: Last Man Posting

#14862 Post by Bellhead »

And those are some of the points I was referring to. In school, they teach you theory, rather than practice. If the theory says it's strong, that's that, and there's nothing you can say about it. Think about vintage engineering, versus current using CAD programs and such. Engineers didn't rely as much on theory when constructing new designs, and instead formed ideas based on common sense knowledge and proven methods, without focusing on weight reduction, or as much on cost. As a result, equipment of the era was simpler, using stronger components than necessary, resulting in (at times) decades more reliable use. It's not that schools teach corner-cutting, per se, they just teach you to only use what's necessary to save on materials. It requires more skill, sure, and can save in weight and cost of materials, but decreases the overall durability of the product.

Compare, for instance, an old CRT TV to a modern flatscreen. Per hours of usage, the CRT will have a lower quality picture and will use more power, but will last far longer. Drinking glasses are made with less glass and more intricate designs, meaning they look better, but will shatter if dropped from one foot in the air. There's always a downside to that kind of efficiency of engineering.

It's like the Axe Sharpening principle: The sharper the point, the better the cut, but the duller the point, the longer it will cut with the same quality. Schools teach how to cut the sharp point, whereas vintage engineers either went for the dull point, else some compromise between them, resulting in a long-lasting, moderate quality product. Think... Nokia 3310 vs Droid Razor. The Razor had more capability, color screen, thin body, camera... But the 3310 is, and always has been, considered a better phone, because they're almost impossible to destroy during any sort of normal use, despite the near complete lack of function beyond call, text and Snake.

Back when I was in school, I had my own view on it: School teaches you to design something light, cheap and efficient, and rely on tight tolerances and control systems for reliability, rather than designing it to function well, and working on efficiency from there. Case in point: Jeep 4.0L in-line 6, and just as famously, the Mopar 225 Slant 6. Inefficient, but cheap and easy to maintain, and indestructible.
Gearhead mechanic in the digital era, who will probably grow up is in the process of growing up to be a very grumpy old man.

User avatar
Technic[Bot]
Grand Templar
Posts: 1246
Joined: Sat Jan 27, 2018 9:48 pm
Location: México
Fav. Twokinds Character: Raine!
Contact:

Re: Last Man Posting

#14863 Post by Technic[Bot] »

It is not that back then engineers did not relied on theory that much., because they preferred common sense or something like that but because they could not solve the equations but for the most trivial cases, to deal with this you add a higher security factor on you calculations as a way to counter the uncertainty. this is why most stuff designed back then is bulkier and sometimes more performing than modern counterparts.
For the past 100th years the theory for most everyday stuff has not changed that much, except for electronics and electrical engineering as it is a rather modern field, the equations are the same however you did not have closed form solution for the general case, even today we don't but today we can use computer to run computationally heavy simulations, such as Finite element analysis to get a much better estimate of actual stress state of piece or part, for example. As such you do not need to add such a high security factor to compensate as your uncertainty is much lower. Leading to smaller more efficient designs.
Similarly manufacturing has advanced a lot, back then you could not design something that depended on tight fits as you simply could not build such tight tolerances. This again has changed due to the usage of Computer Numerically Control machines has led to more precise manufacturing.
Also it is not that all modern stuff is less durable than 1900s stuff, sure customer habits have changed a lot so it makes little sense to make a car that last a decade if people will simply change it each year and you can make a lot of money on recurrent customer spending but still. We do not remember [censored] build in the 1960's because only high quality reliable stuff made it from the 60s to today, the rest turned into dust, that is Survivorship bias
What you are definitely right about is that at is core Engineering is about optimization, making the most with the least. That being said most of my professors conceded that doing something efficiently required lots of practice and experience and we should focus in just doing it effectively, meaning make it work, and the we could think about making it more efficient.

Also you mentioned before a wind powered vehicle. Never heard of something like that and it was quite an specific example. It also sounds interesting, could elaborate?
Tornir wrote: Sat Jul 31, 2021 7:29 am Which is why they prefer to interfere in manufacturing, after you guys have handed it off; removing "non-essential" safety features, or substituting sub-standard materials.
Here's a notorious example of a production FUBAR by the bean counters.
I have hear the sadly common horror stories. I think the challenger blew up for something like that.
There are three things that motivate people: Money, fear and love.
Links to my ramblings:
Twokinds [of] data
PhpBB in the age of facebook
If you are new to this phpBB thing:
BBCode guide

User avatar
Bellhead
Templar Inner Circle
Posts: 4012
Joined: Wed Oct 23, 2013 11:17 pm
Location: New England, US
Fav. Twokinds Character: Keith and Natani

Re: Last Man Posting

#14864 Post by Bellhead »

My point still stands. Over the last half century, production has slowly shifted from "simple and reliable" to "complex and short-lived". Survivorship Bias would only apply, if any particular given device had been discarded due to failure, rather than age, or perceived obsolescence. "Out with the old, in with the new" does not necessitate that the original had failed. For instance, I have a desk fan from the early 1960's. No-name brand, crummy switch, made from cheap sheet steel. Found it sitting in the shed under a leaky roof. Cleaned off the dust, and it works just fine, after all that abuse. Take a look into some older hardware, if you have some, and you'll find that it will function just as it did several decades before, even through wear and tear, with little difference in function.

I stand by the Axe Sharpening principle. The change was gradual, as technology improved, but it improved to the point that the "Next Better Thing" came so soon that durability no longer mattered. And that brings me to another point that was brought up back in High School: Planned Obsolescence, or designing something to fail and/or wear out after a set amount of time. An engineered life expectancy, as it were. It's the basis of the old standby, "it died right when the warranty expired". I have (sorry for yet another "for instance") a snowblower. Bobcat model, sometime between 1950 and 1970. Briggs & Stratton 7 hp. It came brand new with a 6-month or New Year's Day warranty, whichever came second (I found the original warranty card). The Snapper model that we replaced it with, had a 3-year warranty, and stuff started breaking on it after 4 seasons. That Bobcat? I've replaced the pull-start return spring, inner tubes and the drive belt. After decades of use, then years of neglect, then several more years of use, that was all it needed. And I once got a bolt stuck in the second stage so hard that it literally knocked the paint off the other side of the housing, in the shape of the bolt. No new snowblower could go through that, and not need major repairs.

On the subject of wind-powered vehicles:
That was an 8th grade science project. "You live on a desert planet with no fuel, but lots of wind. Build a vehicle." Several groups built super lightweight vehicles, using plastic bags as sails/parachutes. I built a metal frame using a vintage Erector Set, and used a mast to hold a pair of plastic bag parachutes. I had the slowest acceleration of any group that moved by the box fan we were using, but was only 8" short of the longest distance covered. More than 7 feet, if I recall. My reasoning was that, no matter how efficient your vehicle is when moving, it must still be able to remain stopped when you're not driving it, on a planet with tons of wind that blows around lightweight objects. A heavier vehicle would be slower, sure, but it would be FAR easier to control through sudden and unexpected strong gusts of wind. Like a full-size sailing ship, verses a catamaran. Sure it's faster, but does that help if you can't keep it upright under a heavy gust of wind? That was my theory, anyway. I was pretty happy with the results.
Gearhead mechanic in the digital era, who will probably grow up is in the process of growing up to be a very grumpy old man.

User avatar
Technic[Bot]
Grand Templar
Posts: 1246
Joined: Sat Jan 27, 2018 9:48 pm
Location: México
Fav. Twokinds Character: Raine!
Contact:

Re: Last Man Posting

#14865 Post by Technic[Bot] »

I do not really have any "old" (60s to 50s) stuff around, as all of it died. Unfortunately if you lived out of the US/Europe you rarely got the "good-old" stuff as just very few, high income people were able to import it. So you made do with what was available locally and random imports. But I digress.

Sure today very little stuff is made to last and most of it is barely works a couple weeks but i think you are confused that is because of market pressure and corporate culture not with the lazy book-smart engineers who have never touched a part. Believe me they want only to have fun make a good product out of the meddling noses of upper management, that is why the happiest engineers work in companies that make stuff for other companies: Turbines, machine-tools etc. Not something mass marketable.

First back then tools and similar were meant to last a lot this is not because back then they were made with love or something but because most people could not afford to replace a tool multiple times because for most of history most people barely made enough to stay alive. No one would buy a hammer that would break after a month because no matter how cheap it was they could not afford it. When people began getting more discretionary income they were more willing to replace with a newer more performant model of anything. It also gives people choice, sure "el cheapo" screwdriver may only work once and costs pennies but if all you want is tighten that one screw why spend on expensive equipment you never gonna use?

Second planned obsolescence is not new sure today you can remotely throttle a device to "nudge" customers into buying a new one, like apple does. And do not get me started on new tractors which are actually ilegal to repair for anyone but certified John Deere mechanics. But even back then it is not hard to design a fully mechanical part that is designed to withstand only a N amount of work cycles. Fatigue in wonderful of course depending on the material, steel for example, you can also design it so it never wears out. At the end of the day if customer buys again that is profit and that is the only thing suits care about.

Also there are different levels of quality. As one of my professors used to say: "Everything is Chinese, but some Chinese stuff is meant to be used once and some other is meant to last decades". Honestly I doubt your fan was all the cheapest fan of its day. In strict sense quality is probabilistic a higher quality part is less likely to fail, but given no process is perfect there is the change you ended up with a bad batch of high quality products and on the other hand you may end up with a cheap piece of garbage that lasts lifetimes.
Moreover simple stuff is generally more robust than complex stuff by definition if you only do one thing it is easier than doing it great, but if you need to do more than once, well things get complicated. And yes old cars only moved you from A to B hence there was little in the way of something going wrong. More modern cars do have creature comforts like AX but also have some nice features like ABS, seatbelts and airbags which save lives. They also more fuel efficient and easier to operate.

finally you may enjoy this video about wind powered vehicles:
Propeller craft
There are three things that motivate people: Money, fear and love.
Links to my ramblings:
Twokinds [of] data
PhpBB in the age of facebook
If you are new to this phpBB thing:
BBCode guide

Post Reply