I made me a slide rule

D

Don Luis

Joined
Dec 26, 2002
Messages
2,473
I have several slipsticks from my high school and college years, and for a while I've had the idea of making one, finally took the time to do it.

For the scales I scanned one of my old ones and made it all with stuff found around the house: cardboard, glue stick, cellophane tape, plastic from some packaging for the cursor, etc.

It turned out ok though some cuts are not perfectly straight, they are a bit rough where the slide meets the body and it gets a little hard when moving the slide far to the left.

I'm thinking maybe I can do another one with the scales printed in photo paper and taking better care when cutting out the pieces.

Here's a pic for those who remember these cool old gadtgets

Luis


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Awesome! I have never had to use a slide rule for education or professional purposes but I find them utterly fascinating. I have two slide rules and I have contemplated making my own. I actually would like to build a circular slide rule since they never run off the scale. Thanks for sharing and it looks very cool.
 
Fantastic!!!! Very cool man.------Does it come with a small clip blade?;)
 
That's very cool. :thumbup: It's been a long time since I've used one, but I still have my father's and my grandfather's around for sentimental reasons.

Jeff
 
Very nice work. I used them for years and still have a couple of slipsticks. I wish I knew what happened to my circular rule!

Electronic pocket calculators didn't hit the market until I was 26 years old, so I had a lot of time to play with slide rules. :)
 
I actually would like to build a circular slide rule
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Before deciding to scan my own I did a bit of Googling, here's a couple of sites I found about making a circular slide rule:

This one fits in a cd case:

http://sliderulemuseum.com/SR_Scales.htm#YingHum

This one seems a bit more complicated:

http://solar.physics.montana.edu/kankel/math/csr.html

I still have my father's and my grandfather's
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My father had degrees in physics and chemical engineering and had a bunch of slide rules , he taught me how to use them, but I have no idea what was of them.

Electronic pocket calculators didn't hit the market until I was 26 years old
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IIRC I first used an electronic pocket calculator at age 21 during my senior year in college (borrowed it for a statistics exam).

Luis

Edited:

The Wikipedia link posted by Esav is good and points to some interesting how-to's at the end of the page.
 
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knarfeng said:
(Yes, I know I am a geek and I have a collection of slide rules to prove it, including the ones I used in high school and college.)
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Interesting site you posted. My dad has several pretty complex slide rules around from his college days in the late 60s and I've always been fascinated by them. But I didn't inherit his mathematic ability (I'm mathematically illiterate) so I can't figure them out... hell, I barely passed statistics in college using a calculator ten years ago.
 
Man, that brings back some memories. I still have my old slide rule somewhere I think.

If you want an added challenge, here is something I used way back when I was first learning navigation. The Jeppesen Flight Computer. A lot of sliding and spinning to be had there. :)

http://www.marvgolden.com/jeppesen/fc.htm

Ahhhh... those were the days.
 
I actually have a sliderule ap on my iPhone. The young bucks think its funny until they see show fast I can get darn close to the answer... close enough for most practical purposes.

The art of estimating and the concept of "close enough" is something which is being lost. I'm aways amazed to ask some young engineer, "What shall we tell the manufacturing test folks that the voltage at this node should be?" And the young kid gets out his laptop and fires up pSpice and five minutes later announces, "3.312548 Volts, Sir."

"I doubt it."

"I'll double-check my calculations. Maybe I entered something wrong."

"Oh no. You're fine. My back-of-the-envelope estimate is 3.3 Volts. But I seriously doubt that it will be 3.312548 Volts. You see, you forgot the fact that R1 and R2 are 1% tolerance parts, the gain of the amplifier is actually temperature dependent, and that's to say nothing of voltage coefficient of resistance. Besides, the best meter we have in the house can't measure three-point-something volts to the microvolt, not even the millivolt."

"The big one can measure millivolts."

"No, it can't. It's got three counts of error in the last digit, and that's assuming it's in cal which it's two years out of. And the testers on the line don't use that meter anyway. If you don't want a stack of rejected units on your desk to troubleshoot, you have to allow for the calibration of their test equipment too. 3.3 Volts is good enough."



Now, if you really want to get to know the sliderule, forget scanning the scales. Do a little research and find out what the math behind the scales is. Then, have Excel make up each scale in tabular format and then graph it for you. Use that graph to mark your scales.
 
Yes, the difference between precision and accuracy, like fitting and inaccurate rifle with a precise telescopic sight.

The math involved in slide rules is actually not that complicated (if you understand logarithms) and graphing in Excel (or OpenOffice Calc for us Linux users) sounds like an interesting excercise. However, for practical purposes, I would guess the precision of the scan is enough for the accuracy of the rule.

For show, here's my good old Japanese made Relay 150 slide rule in bamboo.

Luis


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Don Luis said:
I have several slipsticks from my high school and college years, and for a while I've had the idea of making one, finally took the time to do it.
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...good God man, why?...the invention of the transistor and ic chips put that infernal device out of business...yeah i remember how to use one, but i don't want to use an abacus either

hp 12c forever...
 
...good God man, why?...the invention of the transistor and ic chips put that infernal device out of business...yeah i remember how to use one, but i don't want to use an abacus either
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He he, I have these things too, I guess I'm just a geek...

Luis


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Don Luis said:
He he, I have these things too, I guess I'm just a geek...

Luis


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Hey, you have one of those great mechanical calculator thingys, damned if I can think of the name of them right now. Where did you get it? How much did it cost? Where can I get one?

Enquiring minds NEED to know! :)

.
 
The Curta model 1 belonged to my father, it's a bit scratched and the clearing ring is broken, the canister where it stores has holes that he made to add a strap and belt clip (both gone now), but it still works fine, I would guess it's form the 1960's.

The Addiator is glued on the back of my Faber Castell 67/54 R (which is the one scanned for my home made), IIRC I found this one sometime in the 1980's at a local office supply shop.

I don't remember much about this particular Soroban abacus, I've had several since I was young (also learned how to use it from my dad).

I don't have much of an idea of prices or where to buy, I do believe the old Curtas don't go cheap, IIRC they were always expensive due to the complicated mechanism and need for precision manufacturing.

Luis

Edited:

Just found this site, which has links to a Curta simulator and a youtube video.
 
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Don Luis said:
The Curta model 1 belonged to my father, it's a bit scratched and the clearing ring is broken, the canister where it stores has holes that he made to add a strap and belt clip (both gone now), but it still works fine, I would guess it's form the 1960's.
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That's the one, I'm envious. I love those things, I'm going to have to start saving for one. Assuming I can find one of course!
 
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