The Scotsman SR1 mechanical calculator

The Scotsman SR1 is a rebranded Monroe model L. It was sold by the Calculator Equipment Corporation in around 1958 or 1959.
Related videos:
• The Monroe Calculator ...
• The mechanism of the M...
For more information about this and other machines in my collection, please visit my website:
www.jaapsch.net/mechcalc/
0:00 Introduction
0:35 History
2:12 Demo
2:38 Outro

[@stephenfreeborn]

Never heard of Scotsman. Thanks.

[@jaapsch2]

I hadn't either till I saw this machine for sale on eBay.

[@tompsheridantsheridant7354]

CAN IT PLAY **FORGE OF EMPIRES**?

[@ChrisStaecker]

Watch til the end!

[@MattMcIrvin]

In the US at the time there was a stereotype of Scotsmen as cheap, so you'd see "Scotsman" or "Scotch" used as a brand name indicating something inexpensive or thrifty (I think that was where 3M's "Scotch tape" came from).

[@friiq0]

If it’s just made of all rebranded Monroe parts, is it really a true Scotsman?

[@jaapsch2]

😄

[@rewindoflow]

Hi Jaap, I have an unidentified pinwheel Brunsviga which is in full working order (though a little beat up) except the slide has completely seized, and I can't work out how to get at the screws holding on the rails without disassembling absolutely everything. Do you have any advice? Also, I have been interested in aquiring an electromechanical model that can automatically handle multiplication/division (Similar to the Frieden STW10). Are there any models that are widely available in Europe that I should look for?

[@jaapsch2]

With regards to the Brunsviga, do you mean that the carriage is stuck? They usually have a screw underneath for locking the carriage in place for safety during transport or storage, so make sure that isn't the problem here. A nice early machine similar to the Friden is the Rheinmetall SAL or SASL from the 1930s, and nice postwar machines are any Madas models with the extra multiplication register at the front. They're not that common, but almost never found in the US.

[@rewindoflow]

@@jaapsch2 Thanks for the help! On further Inspection ist appears to be a Brunsviga Nova 13. There is indeed a screw underside of the calculator (which I did notice before), but it appears to be the cariage limit stop and removing it doesn't affect anything. My initial guess was that things have rusted and siezed, however there is a tiny bit of movement, and opening it up I am a bit confused by how the gears from the carriage move past the rotating drum as they are meshed closely and there doesn't seem to be any way for them to move out of the way. Not sure what is going on there - how do pinwheel calculators usually handle this? Thanks for the suggestion for the Rheinmetall, I will take a look!

[@19ghost73]

​@@rewindoflowAny success with your Nova 13? That screw (with a thin bar through it) is indeed a transport safety screw, as Jaap wrote earlier, and it is not meant to be screwed out, just loosened. The pinwheel "drum" has no pins or teeth sticking out & interferring with the carriage when the drum is in the neutral position, i.e. when the sliders can be moved. Basically ALL pinwheel machines are the same when it comes to this. Watch any YT-video about a total disassembly of a simple pinwheel calculator to get a feel for that. "FELIX M"-type Soviet calculator dismantling videos are helpful for that. Usually, WD40 and/or kerosene or petroleum works very well to unseize these machines...and, later, modern sewing machine oil is good for lubricating without gumming up.

[@rewindoflow]

@@19ghost73 As it happens I managed to work it out (literally). Turns out that there was just a ding in the side, which had caused it to get completely jammed within the slide guide. Some big whacks with a hammer eventually freed it (but not before I took the rotor out). The whole thing is a bit rusty and all the paint is flaking off, so I'm wondering about doing a complete disassembly, but maybe it is possible to touch it up without disassembling all the fiddly wheels.

[@minetest-dog-of-war-server]

I'd like to see it do a calculation

[@jaapsch2]

Well, I showed 256x256=65536. If you want a more in-depth explanation, watch my older Monroe video: kzbin.info/www/bejne/a4Wrg4GreZmso80si=ecgv7EsEoBK-UXpX

[@minetest-dog-of-war-server]

@@jaapsch2 it's an amazing machine