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1938 Practical Mechanics magazine


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Brought a couple of old magazines from a  charity shop.

One is a August 1938 Practical Mechanics magazine. Whole section on motorless flight with a great front cover showing the glider taking off from the top of a car!
Other articles include an article on a new plane engine, how to temper metal, build your own boat, experiments with polarised light and testing metal to the breaking point.

Just a great eclectics mix of in depth articles that you never seem to see in magazines these days...

Mike 

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That's a great find.

Modern magazines like PM can't cope with that nowadays. They've been overrun by dedicated YouTube channels. My science-teaching colleagues think that those channels are the best invention since sliced bread - and perhaps a better invention. You still get the same info, even more perhaps. My wife used to work as a communications director for a Dutch publishing company (owner of UK's Effacts among others) and around the end of the last century, they already started switching to digital content. Which was rather tricky back then, because lawyers etc are (were) pretty 'old school' when it comes (came) to taking in new information. 

Still, that PM is, of course, a monument of information from an era gone by.

Menno

 

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What is quite scary is the age, 1938.

Approx 40 years after it was published I was probably doing some of the light experiments at skool. And that was about 40 years ago.....

Makes me ponder how fast time passes. My dad was born in 1931, and we are out celebrating his 88th birthday today with a lunch (he is not so good in the evenings these days) but he has lived through so amazing times. Not always in a good way, but then again he loved his wartime years, sent away to live on a farm with relatives. 

And yes, youtube videos can be damn useful, once you find one by somebody who understands (a) what they are doing and (b) can actually get decent footage so you can see what you need to do. (used it yesterday to adjust the clutch on the puddlejumper, first 2 videos were hopelss, 3rd time lucky and it was then I realised the knob I could just get my fingers to, while the battery tray tried to sever my arm,  was correct but seized. Persistence and blood got there in the end.)

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Nothing new under the sun so they say.  The polarised light article reminded me that liquid crystals were discovered in 1888 by Friedrich Reinitzer.  It took a few more years for the practical applications to emerge.

 

 

Edited by 4APete
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On 2/15/2019 at 6:07 AM, MennoR said:

That's a great find.

Modern magazines like PM can't cope with that nowadays. They've been overrun by dedicated YouTube channels. My science-teaching colleagues think that those channels are the best invention since sliced bread - and perhaps a better invention. You still get the same info, even more perhaps. My wife used to work as a communications director for a Dutch publishing company (owner of UK's Effacts among others) and around the end of the last century, they already started switching to digital content. Which was rather tricky back then, because lawyers etc are (were) pretty 'old school' when it comes (came) to taking in new information. 

Still, that PM is, of course, a monument of information from an era gone by.

Menno

 

I wonder whether the YouTube info will still be around - and more to the point readable - in 80 years time?  Storage methods and media formats change so quickly now that unless things are constantly being moved to the latest one, the data soon becomes inaccessible, either because you can no longer read the media or the encoding method is out of use.

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4 hours ago, DeTRacted said:

I wonder whether the YouTube info will still be around - and more to the point readable - in 80 years time?  Storage methods and media formats change so quickly now that unless things are constantly being moved to the latest one, the data soon becomes inaccessible, either because you can no longer read the media or the encoding method is out of use.

the last major user interface development project i was leading back between 2009-2012 i used to infuriate some of the developers by testing via a 1mb broadband link an using a windows 98 pc that i kept exactly for that purpose. i used to keep throwing stuff back at them as broken for xyz reason, they would come back and say it isn't "it works fine for me" so i would send them back trace files showing the code failing and screen shots and videos of mangled screens. they would then come winging back that "well your running w98 it doesn't support the fancy bit of coding i put in, and the reason the other bit is failing is that the timers i put in are running out because of the slow connection" i just used to pm or email back "who are you to dictate what technology and broadband speed our customers, customers, end users must have?" in the end they got the message and the amount of inefficient bloat code they just copied in because it worked and saved them even thinking about what they were writing fell dramatically.

a bit of a hang over from one of my first project managers when we moved to developing terminal/green screen on-line applications for users, if you gave him something you had written proudly saying its working and ready to test, he would humour you for a few mins running some stuff, then would lift up both hands and crash them up and down on the keyboard until the code crashed, or you got into an error message situation that you couldn't exit from without turning the terminal off and and again, and then say "nope it doesn't work" you woudl go.. but, but, but.. and he would say "look i don't know what keys i pressed to cause the error, but neither will the user when they call you when the software is live, go away an improve your error handling" and he was correct and over the years we came to conclude that in a well written program 80% of the code was error/exception handling and only 20% actually did what the spec asked for. its interesting today to see how much commercial software /web sites seem to fail to have  good error/exception handling, users seem more than happy and almost seem to expect to have to restart, put in the data again when something goes wrong.

alan (the Luddite)    

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interesting comments re testing software..
I have just fitted a 2 speed wiper motor to my Herald and thought it would be a good idea to control it from an Arduino Nano. This would give me two speeds of interrupt wiping (**) as well as slow and fast speed. Decided to do the 'parking' in the software rather than the way Triumph/Lucas did it (there solution was actually quite clever). Hardware all hacked together on the desk and software written. then a couple of days sorting out all the issue with signal noise, coping with fault conditions etc realising why Lucas shorted the motor when it parked (to stop it moving). Then build the hardware install and test it in the car (replace the arduino again as they are not happy having anything over 5V on any inputs..), build a  modified Herald wiper switch to give me 5 positions etc.

So the software was a very small part of the design but the testing/debug time of the whole system took all the effort.
This wasn't really a surprise as I used to write software/design hardware  for oilfield downhole tools, at least now I only do it as a hobby and the only pressure is from myself!

BTW the Ardunio is very nice I would prefer to use a Microchip processor but not having any PCB manufacturing its easier to use a prebuilt processor board.

Mike

** off to Scotland again to do the NCR800 sort of extended North Coast 500 and don't expect the lovely weather we had last year!

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1 hour ago, Nick Jones said:

Doesn't sound like the easiest way of doing it Mike!  Lucas's parking wiring method is a bit too clever as it prevents the use of a modern intermittent wipe relay..... or at least, I'm not clever enough to make one work :unsure:

I think you correct but its still fun if you like electronics!
What Lucas did is to short the motor  when it gets to the park position. the reason for doing this is to make the motor stop almost immediately (**) otherwise it will continue to rotate and move past the parked position (depending on the friction from the wipers blades) and then the  blades wont always stop in the same position.. Quite clever really and I only understood why the did it when playing with the motor on a the bench.

mike

** used to make my own slot cars and remember modifying the hand controllers so that it would short the motor to improve the car braking! Had forgotten about this until I started playing with the Lucas wiper motor!!!!

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14 hours ago, Nick Jones said:

Doesn't sound like the easiest way of doing it Mike!  Lucas's parking wiring method is a bit too clever as it prevents the use of a modern intermittent wipe relay..... or at least, I'm not clever enough to make one work :unsure:

Does this apply to the later tr6 wiper motor Nick?

ive built and installed the Maplin intermittent wiper timer kit and it works well on my 74

steve

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Yes I think so Steve.  We were successful with a kit very similar to the Maplins one on Chris's Spit, but I previously spent a long time trying to get one of the Bosch packaged relays (as used on all sorts of moderns) to work without success.  It could just be that I'm not clever enough though!

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Damn, that's complicated.  Having established that, once they leave the (manually selected) park position, the wipers describe a juddery arc of approximately 20deg, slightly asymmetrically to vertical, I have decided that marginally impaired vision through the rain-blurred screen is no handicap to forward propulsion.  Indeed, it is an essential part of the Triumph Experience.

As with many of the mechanical interfaces in my life, expletives seem to overcome minor obstacles like these.

Paul

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The Smart Screen is a nice thing - which does pretty much the same job as a particular Bosch relay, available for maybe a 10th of the price from a scrapyard if you know what you are looking for.  That is, if you can get the blasted thing to play with the Lucas motor - which I can't.

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10 minutes ago, Nick Jones said:

The Smart Screen is a nice thing - which does pretty much the same job as a particular Bosch relay, available for maybe a 10th of the price from a scrapyard if you know what you are looking for.  That is, if you can get the blasted thing to play with the Lucas motor - which I can't.

So endeth the lesson?

I used to try and play with electronics but it was a losing battle after my father in law died.

I am ok on relays and simple circuits (megajolt and Megasquirt got the old brain cells going) but a long with help from friends here I beat the B**gers!)

Roger

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1 hour ago, MennoR said:

TBH... my TR drove only 26kms last year... Combine that with the splendid summer we had and you don't have to be a wizz-kid to figure out that it was 100% dry motoring!

 

Maybe you do not drive in the rain but may be sometimes you drive below sea level !!

and we complain about salt on the roads !!!

H

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3 hours ago, Hamish said:

Maybe you do not drive in the rain but may be sometimes you drive below sea level !!

and we complain about salt on the roads !!!

H

Not where I live. I live a whopping 12 mtrs above sea level! When the polar ice melts and the sea level rises, my house will transform from a house at the edge of a park to a house on the beach! I just have to change to a beach bum... 

Back on topic: I've decided to sell the Porsche so that I can use my spare time to drive the TR. 

Menno

 

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  • 2 weeks later...
On 2/21/2019 at 10:34 PM, MennoR said:

Not where I live. I live a whopping 12 mtrs above sea level! When the polar ice melts and the sea level rises, my house will transform from a house at the edge of a park to a house on the beach! I just have to change to a beach bum... 

Back on topic: I've decided to sell the Porsche so that I can use my spare time to drive the TR. 

Menno

 

Menno

Sold my Porche 2 weeks ago

Got an SL500 as a daily driver instead . . . .nice for an elderly person of the male variety.

John

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