Surely somebody remembers these pocket mechanical add/subtract calculators.
I was thinking of trying to make a large one from wood as a math teaching
aid. Has anybody here done it? The mechanism is pretty simple, and it
looks like it would be easy to build, but we all know how the easiest
looking projects can turn into a mess when it comes to actual execution.

Joe Bramblett, KD5NRH wrote:
Surely somebody remembers these pocket mechanical add/subtract calculators.
I was thinking of trying to make a large one from wood as a math teaching
aid. Has anybody here done it? The mechanism is pretty simple, and it
looks like it would be easy to build, but we all know how the easiest
looking projects can turn into a mess when it comes to actual execution.

Joe;

I can't give you any help on designing and building one but I seem to
recall seeing one years ago. This looks like an exciting project though.
If you do make one please publish your project on a website somewhere
and let us know how it goes.

Dave WD9BDZ

"Joe Bramblett, KD5NRH" wrote in message
4...

Surely somebody remembers these pocket mechanical add/subtract
calculators.
I was thinking of trying to make a large one from wood as a math teaching
aid. Has anybody here done it? The mechanism is pretty simple, and it
looks like it would be easy to build, but we all know how the easiest
looking projects can turn into a mess when it comes to actual execution.


Sorry no plans but I do have an Addometer with its original leatherette
case. Mine is about 12" long and probably would not fit your pocket very
well.

Talking about abacus ? I bet the third from the bottom on this page :
http://www.vintagecalculators.com/ht...lculators.html

Kingson Four-Rule

Martin

Joe Bramblett, KD5NRH wrote:
Surely somebody remembers these pocket mechanical add/subtract calculators.
I was thinking of trying to make a large one from wood as a math teaching
aid. Has anybody here done it? The mechanism is pretty simple, and it
looks like it would be easy to build, but we all know how the easiest
looking projects can turn into a mess when it comes to actual execution.

"Martin H. Eastburn" wrote in news:ZjW6l.88147
:

Talking about abacus ? I bet the third from the bottom on this page :
http://www.vintagecalculators.com/ht...lculators.html

Kingson Four-Rule

Martin

My Dad had one like that, but it got lost

--
Best regards
Han
email address is invalid

"Han" wrote in message
...
"Martin H. Eastburn" wrote in
news:ZjW6l.88147
:

Talking about abacus ? I bet the third from the bottom on this page :
http://www.vintagecalculators.com/ht...lculators.html

Kingson Four-Rule

Martin

My Dad had one like that, but it got lost

I had one like that when I was a kid. I think it was the Exactus model shown
on the web site... the instruction manual looks familiar to me! I still have
a circular slide rule with the case and instructions... I got the slide rule
just as the TI pocket calculators were starting to drop from the $400-500
range to about $100 in the early to mid-70s. I figured the slide rule would
be a neat relic. Wish I'd realized that about the Additor type calculator.
;~)

http://www.vintagecalculators.com/html/exactus.html

I can recall how carefully you had to stick the stylus in the little notches
and move them... To get accurate results you really had to pay attention and
have a feel for the tool, much like using my hand tools vs. running things
over my jointer or through my planer. ;~)

John

"John Grossbohlin" wrote in message
m...

"Han" wrote in message
...
"Martin H. Eastburn" wrote in
news:ZjW6l.88147
:

Talking about abacus ? I bet the third from the bottom on this page :
http://www.vintagecalculators.com/ht...lculators.html

Kingson Four-Rule

Martin

My Dad had one like that, but it got lost

I had one like that when I was a kid. I think it was the Exactus model
shown on the web site... the instruction manual looks familiar to me! I
still have a circular slide rule with the case and instructions... I got
the slide rule just as the TI pocket calculators were starting to drop
from the $400-500 range to about $100 in the early to mid-70s. I figured
the slide rule would be a neat relic. Wish I'd realized that about the
Additor type calculator. ;~)

http://www.vintagecalculators.com/html/exactus.html

I can recall how carefully you had to stick the stylus in the little
notches and move them... To get accurate results you really had to pay
attention and have a feel for the tool, much like using my hand tools vs.
running things over my jointer or through my planer. ;~)

John


John,
Lots of them still available on eBay - enter
mechanical calculator
in the search box, and the bottom of the page will show several Addiator
type devices in the eBay stores section, as well as a couple in the auction
section.
Kerry

"John Grossbohlin" wrote in
m:

I figured the slide rule would be a neat relic. Wish I'd realized that
about the Additor type calculator.

I inherited granddad's log-log duplex Pickett slide rule. It was good for
some funny looks when I used it on a radio exam. I still use it from time
to time when I'm stuck without a scientific calculator.