Alan's Mechanical Calculator Page
My collection of old adding machines
I have a collection of mechanical calculators that I have rescued and returned to full working order. My interest in
these machines began when I happened to see a YouTube video featuring a Friden machine. After telling someone about
my newfound interest I was later gifted an adding machine for my birthday, later someone else gifted me a couple more
and this resulted in my acquiring more and more of them until I now have 17 of them.
These machines seem to attract little interest or value, most of them have been given to me or I have bought for under
£20, I like to think I am rescuing them from being lost forever and some day interest in these machines may increase.
See the Schickard Calculator I made HERE
and a video of my latest acquisition in operation (a Diehl model E15) HERE
You can see more about these machines here: Jaapsch
Prof. Christian-M. Hamann
lots of great YouTube content GrumpyTim
See a comptometer in use back in 1931
Curious Mark's video about his Friden
Some handy tips I have learned whilst restoring these machines:
1 - Most problems you will encounter is the old oil has turned to a stiff, sticky mess and glued moving parts together.
A electronics heat controlled hot air gun is very good for softening it up so you can get it moving enough to work
some new oil in to it. In extreme cases I have found heating it by resting a soldering iron on to it has worked
2 - Solder is very handy for repairing broken parts (I find an electronics soldering iron and solder works fine),
with small parts you can actually form the molten solder in to shapes and it is a very handy way to build up worn
surfaces. I have even in one case managed to replace a broken gear wheel tooth in this way which worked
surprisingly well. It will of course not be as strong as the original metal but it works and also is very easy to
remove at a later date if required so doesn't cause any permanent damage to the machine.
3 - Water slide decal printer paper is very handy for replacing missing text/labeling etc. and also very handy for
putting the text on replacement key caps. You simply print your required text/image (if printed on an inkjet you
need to then seal it with a spray laquer), cut it out, put in some water to soften the glue and slide it in to place.
This is very good for putting the text on replacement key tops.