Slide rules rule - and you can still get them new

[Sigmoid]

Just wanted to throw this into public domain...

Slide rules were a staple of an engineer's tools for almost a century, up until scientific calculators became commonplace. Also, if you've been wondering why old engineers can easily guesstimate calculations you'd reach for your calculator to do, it's partially because they spent their youth using slide rules.

I recently wanted to buy one, and was confronted with the fact that literally nobody is making these anymore... Well nobody except for a single Japanese manufacturer, Concise. (http://www.concise.co.jp/en/) Their webshop is pretty crap, and I had to fax them the payment details, but they offered great customer service, and the circular slide rule (the "No. 300") arrived pretty quick, and is a great tool to have.
(For simple calculations, it's a lot less effort to grab it than to unlock my iPhone, start Pythonista, and enter the calculation.)

So if you were thinking about getting one, you should get it from them. Let's not let the last manufacturer fold or drop out of the market.

[steve30]

Cool.

I wouldn't mind a slide rule just for the fun of it, but I don't particularly need one since I have my HP 35S, and my PC has XCalc.

Is there much difference (usage wise) between a circular slide rule and a straight one?

[zapta]

You can install a slide rule app on your smart phone.

[Lightages]

I am a bit of a slide rule fanatic. I was able to stop my sick addiction at 53 slide rules. I still want some specific models but it had to end.

You can see any slide rule fantasies here:

http://www.sphere.bc.ca/test/sruniverse.html

If anyone wants to buy me a nice Pickett N3P, I would be very happy!

[jobog]

Every time I come across mine in a drawer I think I should throw them away but I just can't force myself to do it.  One day my kids are gonna wonder what the hell they are.  Maybe they can mix paint with them.

[cdev]

Its faster.

[cdev]

You can install a slide rule app on your smart phone.

If you can scan one I am sure you can easily make one in HTML using frames.

[atferrari]

I had the oportunity to see an hydraulic engineer, standing up close to a drawing board doing a long  calculation with a slide rule. He kept the rule with the left hand, moving the sliding part with his right  which also held a pencil.

During the process he "took notes" on a paper sheet on the board.

Later he explained to me: the notes were just for keeping track of the decimal point position. Significant digits wehre always in the rule. He did it very fast and seemed quite "natural" to him.

The year I learnt how to use them, electronic calculators became easily available. So I never used them in any calculation other than for academic activity.

Now that I think of it, I am surprised that I learnt to use them by myself.  (No user manual available, really).

[zapta]

Later he explained to me: the notes were just for keeping track of the decimal point position. Significant digits wehre always in the rule. He did it very fast and seemed quite "natural" to him.

The decimal point also depend whether the inner part sticks out to the left or the right. I don't remember the exact rule.

They go well with rapidograph pens and drawing boards.

[German_EE]

I remember doing my exams at school and writing 'SR' by the answers to show that I had used a slide rule. It was a fifteen inch wooden model originally owned by my grandfather, his set of draughtsmans tools came in useful during Engineering Drawing classes as well.

[Mechanical Menace]

I've never come across a slide rule IRL. Through what I've heard about them I can't work out at all how someone could prefer one to a calculator or computer with an interpreter.

But tbh when the latter is available I don't see why people like calculators :/

[Sigmoid]

Is there much difference (usage wise) between a circular slide rule and a straight one?

Not much. On a circular rule the scale wraps around.

Every time I come across mine in a drawer I think I should throw them away but I just can't force myself to do it.  One day my kids are gonna wonder what the hell they are.  Maybe they can mix paint with them.

You should put them up on ebay if you don't want it... Or if you keep them, teach your kids to multiply and divide with them once they understand decimal fraction. It will help them understand numbers better.

Through what I've heard about them I can't work out at all how someone could prefer one to a calculator or computer with an interpreter.

For the same reason some people prefer writing with a pen to typing. Or walking to driving a car.

Anyway, I'm not discounting the benefit of having interpreters and scientific calculators, but for simple calculations, you know the kind where unlocking the tablet, starting the calculator app, and then putting it away takes longer than the actual calculation, it's definitely a feasible alternative.

[Mechanical Menace]

For the same reason some people prefer writing with a pen to typing. Or walking to driving a car.

  People still use pens? 

Anyway, I'm not discounting the benefit of having interpreters and scientific calculators, but for simple calculations, you know the kind where unlocking the tablet, starting the calculator app, and then putting it away takes longer than the actual calculation, it's definitely a feasible alternative.

Ah, I don't think any of the maths I do that's simple enough to not bother with an app etc isn't complex enough to not just do in my head lol. Thanks for the answer

[tggzzz]

Is there much difference (usage wise) between a circular slide rule and a straight one?

Old joke: As a schoolchild I used a 12" slide rule. As a PhD student I used a helical slide rule. As a professor I used a 6" slide rule.

[Wytnucls]

Used this one for a long period, even well after portable calculators made an appearance:
Worth about the same as my antique HP-67 now ($300.00)

[steve30]

Is there much difference (usage wise) between a circular slide rule and a straight one?

Not much. On a circular rule the scale wraps around.

Didn't think there would be much difference. I do think straight ones look simpler though. Maybe it seems less cluttered.

I found a PDF slide rule once. You can print it and make your own slide rule. I think there were instructions as well for cutting wood and sticking the paper down to make a nice accurate slide rule. I didn't bother with that though, I just printed it to check the concept (and it worked fine). I also had a Slide Rule programme on my old Windows box which complemented an HP calculator simulator. Can't remember the names of any of them though.

[TimFox]

I had to quit using my slide-rules due to presbyopia.  Pity.
One thing that younger people don't understand is "slide-rule accuracy" and when that is relevant.
Both my analog and digital spotmeters (for use with large-format cameras) still use circular slide-rules on the side to convert from EV to f-number and shutter time.

[lapm]

Hmm youtube seems to have tons of videos how to use one. Should probably get one in future, just in case civilization collapses or something.

[Howardlong]

Used this one for a long period, even well after portable calculators made an appearance:
Worth about the same as my antique HP-67 now ($300.00)

They are still part of the pilot syllabus here in the UK. I have mine still, although I'm not sure I still know how to use it. Last time I tried to use it was in preparation for route planning for my IMC exams a year or so ago. I can't imagine anyone using them for real anymore, the quality of the software now for flight planning is so good.

[smjcuk]

People still use them. I have a friend with a PPL and we went through the route planning process with a slide rule. Was rather interesting.

You've never lived until you flew 100 miles to a McDonalds at Southend airport in a Cessna.

[Howardlong]

People still use them. I have a friend with a PPL and we went through the route planning process with a slide rule. Was rather interesting.

You've never lived until you flew 100 miles to a McDonalds at Southend airport in a Cessna.

I took my folks out for coffee and a slice of cake yesterday in my 1966 PA28. That was about a fiver for the food and £150 for the fuel. Never used the wizzwheel once!

[smjcuk]

Nice. We were landing at London Southend and were playing dodge the 737s so I'm not sure if the rules are different there (I have very little idea on how it all works)

[Mechanical Menace]

You've never lived until you flew 100 miles to a McDonalds at Southend airport in a Cessna.

Personally I'd say you haven't lived until you've travelled 100 miles to avoid McDonald's.

[atferrari]

Maybe, buying is not needed.

www.antiquark.com/sliderule/sim/n909es/virtual-n909-es.html

Clever people who had the idea to put it online.

[timofonic]

I wonder about the therapeutic benefits of using a slide rule.

Can help in improving math, spatial and motor skills in the same way as Japanese abacus? Because I suck at it.

Are there studies about it?