Old engineering & mathmatics stuff...

[fanaudical]

Back to the math stuff:

I finished my engineering degree with a math minor; I only needed something like 6 more credits to have a double degree in ME and mathematics but was sick of school (and out of money).

I think technically that the majority of trig is planar or constrained to a planar slice of 3D space (unless you're getting into spherical geometry or other non-Euclidian stuff). Algebra plays well in 3 (or more dimensions). I remember calculating some FEA problems by hand where the matrices were ~50 x 50 (which I guess is nothing compared to "real" FEA problems calc'd by software where the matrices are 1000's of elements wide...).

Hardware:

A Keufell & Esser slide rule (plastic) and a laminated aluminum Picket with the extra scales - both with belt holsters of course.





Another Picket with its book and box (no idea where this came from):

[fanaudical]

Another K&E - laminated wood (looks to be walnut which was unusual):



Guess the photo didn't come out that well.

[fanaudical]

Hodge-podge of "old" stuff. Bonus points if anybody else has the same mouse pad (and an old SGI 550 workstation in the garage to go with it).



Not quite sure where the drafting instruments came from; it's older stuff and one of the dividers is engraved as 1940. The dead reckoning calculator was used by my wife's grandfather (who wasn't a pilot but was an engineer involved with aerospace in the 50's). This set of drafting instruments was given to me by one of my college profs as a graduation present; not quite sure on the date.



I have actually used this set many times. The ruling pens work almost as well as my old Rotring tech pens - just don't move your hand too quickly.

Was looking in my chest of drafting equipment for the old fountain pens and Rapidograph mechanical pencils - can't find them. Not sure where my lead holders are either.

(And the secret to keeping the lead in your lead holder sharp is to rotate the lead holder while pulling a line...)

[fanaudical]

Originally Posted by shadowjack1

I use this same book every once in a while. I thought I was the only one,

Audell's is a great book to go through. My copy is very old, pages yellowed, and it's falling apart - I'm almost afraid to open it.

[fanaudical]

And I guess I'll just put these links here (just in case you've read everything at the Museum of HP Calculators website):

https://sliderulemuseum.com/SRM_Home.htm

https://www.sphere.bc.ca/test/ke-sliderule.html

https://www.sphere.bc.ca/test/pickett.html

One piece of calculation hardware that has always fascinated me is the mechanical integrator. I've seen one once in person - fascinating mechanism:

https://commons.wikimedia.org/wiki/File:Mechanical_integrator_CHM.agr.jpg

[jyl]

I'm pretty excited - bought a HP92 on the 'Bay and excitedly awaiting its arrival.

The HP92 was Hewlett-Packard's desktop "financial/investor" printing calculator. https://www.hpmuseum.org/hp92.htm It is much rarer than the HP97 desktop "scientific" printing calculator, which I have sitting on my desk. I have been looking for a HP92 for many years, but they all seem to be $600+. I finally found one for a reasonable price and grabbed it. It has a problem in the paper feed mechanism, but I took the gamble that I can fix that.

Why do I care if it is a HP92 or a HP97? Why do I want either on my desk? Well, sometimes you need to do some quick calculations and don't want to fire up Excel, I have a hard time using an algebraic calculator, and I really have little need for scientific functions but do occasionally have need for TVM and IRR functions. I think the HP92 does bond math too but I doubt I'll use it for that.

[masraum]

Originally Posted by jyl

I'm pretty excited - bought a HP92 on the 'Bay and excitedly awaiting its arrival.

The HP92 was Hewlett-Packard's desktop "financial/investor" printing calculator. https://www.hpmuseum.org/hp92.htm It is much rarer than the HP97 desktop "scientific" printing calculator, which I have sitting on my desk. I have been looking for a HP92 for many years, but they all seem to be $600+. I finally found one for a reasonable price and grabbed it. It has a problem in the paper feed mechanism, but I took the gamble that I can fix that.

Why do I care if it is a HP92 or a HP97? Why do I want either on my desk? Well, sometimes you need to do some quick calculations and don't want to fire up Excel, I have a hard time using an algebraic calculator, and I really have little need for scientific functions but do occasionally have need for TVM and IRR functions. I think the HP92 does bond math too but I doubt I'll use it for that.

Very cool, congrats on the find/purchase!

[red-beard]

My Dad used to guard this during the Korean War. He was 3/4th the way through college (Aeronautical Engineering) when he was drafted. His choice: OCS or Technician at the Supersonic Wind tunnel at Aberdeen Proving grounds, MD.

So, yep, he regularly pulled guard duty on the ENIAC.

[3rd_gear_Ted]

Originally Posted by red-beard

My Dad used to guard this during the Korean War. He was 3/4th the way through college (Aeronautical Engineering) when he was drafted. His choice: OCS or Technician at the Supersonic Wind tunnel at Aberdeen Proving grounds, MD.

So, yep, he regularly pulled guard duty on the ENIAC.

I believe Boolean logic was the programming basis????

[jyl]

Here’s the HP92 elbowing aside the HP97. It needs the printer rollers repaired but that seems doable. HP97 is going on the shelf.

[Tishabet]

Originally Posted by jyl

Four geeky objects in this photo. My 1990 (?) Monroe Bond Calculator, my kit-built RPN calculator watch, the HP Museum USB stick, and a fountain pen.

But is the fountain pen a Pelikan?

I grew up in the TI-82 era so no slide rule for me, but still have an old CRC kicking around:

[plain fan]

I haven't been able to locate my dad's stuff from his time in the Navy but I'm still looking. Just need to dig a bit deeper.

[jyl]

Originally Posted by Tishabet

But is the fountain pen a Pelikan?

I'm a Francophile, so its a Waterman :-)

[1990C4S]

Originally Posted by plain fan

I haven't been able to locate my dad's stuff from his time in the Navy but I'm still looking. Just need to dig a bit deeper.

Out of the blue, my brother offered me my father's slide rule yesterday. He's doing some housecleaning. I will post a picture when I get it. He graduated from engineering 71 years ago...

[vash]

Originally Posted by 3rd_gear_Ted

Algebra is math in two planes
Trigonometry is math in three planes
Calculus is math in motion

and differential equations? i got a B in that class, and i still never understood it. i just followed the steps.

[masraum]

Originally Posted by 1990C4S

Out of the blue, my brother offered me my father's slide rule yesterday. He's doing some housecleaning. I will post a picture when I get it. He graduated from engineering 71 years ago...

Very cool!

[NY65912]

[flatbutt]

Originally Posted by Tishabet

But is the fountain pen a Pelikan?

I grew up in the TI-82 era so no slide rule for me, but still have an old CRC kicking around:

Wow I haven't thumbed through a CRC in years. I still have my Lange's handbook but I loaned my Merck index to a friend and never saw it again.

[herr_oberst]

[masraum]

Originally Posted by herr_oberst

hahahaha.