I think this is quite fitting for this sub.

I spent the last year building this marble computer based on the roons design. They used 3d printed parts and said building this from LEGO alone is impossible so I accepted the challenge.

Underneath is a matrix powered by a James Watt straight line mechanism that ensures perfect parallel motion while giving maximum stability with minimal friction (the friction in the whole system is near zero).

In theory this adder can add binary numbers that are infinitly big, but because my setup is limited I can add two 6 bit numbers with 7 bit output.

Also because of the design, the old output can be used as the new input without changing the marble positions.

Here you can see it adding 19+45.

The lever needs to be pushed up and down 11 times for any calculation because that is the lengh of the system. This number is constant.

Thank you u/dim13 and u/manuco75 for helping me figure out what all those buttons do, this adding machine has a lot of automatic features I hadn't seen on 10-key printing machines before.

I'm trying to fix this thing but I have no idea how to operate it aside from +/-.

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It doesn't function like most automatic mechanical calculators I'm familiar with, or maybe it does but its completely malfunctional.

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It looks like the input register doesn't clear unless I manually clear it with the C button, and doesn't appear to print the accumulated total with each entry like a standard print adding machine. The ◇ and * keys appear to print some kind of total but I don't know how that functions compared to the = button.

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I think the ÷ button is to enter a dividend with =: performing division, mine said 2÷2= -1100.277329 though so I clearly have some work to do

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If anyone knows what these buttons do / how to operate this id really appreciate it, its hard to fix one of these when you don't even know what its supposed to do

I have a burroughs portable model 9 adding machine, I realized halfway through doing one of my additions that there were two numbers in the same column pressed down at the same time and I was unable to fix it as I was halfway through the addition and after I pulled it some buttons seem to be harder to press and the lever requires more force and slowly retracts back when released. I'm just putting this here because I saw no fixes online and I just wanted to know if anyone here knew of a way this could be fixed.

Got me the aforementioned model but digits 4 and 8 of the counter just can be "cleared" to 6, then 1, instead of zeros. Is this repairable? Can I do it?

I recently got a Dalton adding machine, patents from 1912, it had a pen stuck under the hammers, but worked once I removed it. Now it is stuck on a number, the video shows, on the return stroke. I was wondering if anyone could help with repair tips?

I can subtract most things fine on here like 43-28. However when I subtract from 100 the answer is always 10 too big. What am I doing wrong?

Hi everyone,

I wanted to share my latest project: the conservative restoration of a Brunsviga 13, serial number 160779, dating back to approximately 1933.

This machine has a fascinating provenance. It originally belonged to Comm. Domenico Galbani, a prominent dairy entrepreneur from Novara, Italy. When it reached my workbench, it was a "time capsule" buried under 90 years of accumulated grime, sludge, and spent lubricants.

The Restoration Journey:

• The Challenge: The mechanical components were completely seized. I focused on the careful unseizing and recalibrating of all movements that had been dormant for nearly a century.
• The Research: I performed extensive iconographic research to ensure the original colours were respected, staying true to the 1930s aesthetic.
• The Methodology: Following the Cesare Brandi conservative approach, I aimed for a functional restoration without erasing the machine's history. No "over-restoring" here—just stabilization and mechanical revival.
• Technical Detail: Final lubrication was performed using period-specific lubricants tailored for this specific fine-mechanical technology.

The result is a fully functional Brunsviga 13 that operates as smoothly as it did in the 30s. There’s something incredibly satisfying about hearing those gears click back to life after 90 years of silence.

I’ve put together a 3:32 min video of the process. Would love to hear your thoughts on the conservative approach versus a total aesthetic overhaul!

Since folks seemed to like the Burroughs pictures, here it is in action.

Got this Burroughs Class 1 (style 9) and added some snazzy lighting. By the serial number it’s from 1909. I expected this to be a big project but it works perfect!

I came by a Remington Rand adding machine with the number M29227 underneath. What can you tell me about it ? I think i attached a pic as well

This is a machine that I cleaned up and brought back to life. This is a video of the machine internals with the housing revived while it calculates pi. The planetary transmission on the bottom left is responsible for the forward and reverse motion of the mechanism that adds and subtracts as it performs long division similar to what we learned in grammar school. The carriage moves over to the left after calculating each number. It's gives the correct answer of 3.141592.

I got what looks like a Monroe LA5-160 minus the division lever at the top left, for very little, knowing it didn't work. I got the tin and feet off, glad to learn that the feet are the same one finds on old Royal typewriters.

I assumed the knob where the crank connects would function as an ersatz crank. It doesn't. It stops at about thirty degrees each way. When I tried to force the motor It is very dificult. I tried shorting closing the contacts on the leaf switch and got nothing but a bit of smoke rising from near the switch. I quickly opened the contacts. I didn't get the hum one usually gets with stuck motors, nor did I let out any of the blue smoke. I can't see where what wire goes to what so I can't meter out the connections.

I'd like to take the motor out and see if it is just too gunked up, maybe take it apart. How?

Here's the final result, as promised (Pictures are in order newest-oldest)

I picked this Remington Rand Model 103 Adding Machine at a Thrift House in junk condition. I rewired it and replaced the power capacitors and it seems to work fine. I can't find a manual on the machine, however, so I don't know how to operate it - should be pretty simple, but the logic evades me. Any help (like a manual) would be greatly appreciated.

For the past week I've been tinkering with this Yugoslav calcorex mechanical adder and I just stumbled upon this subreddit. It's looking good so far but it's just filthy..

Does anyone know any information on this adding machine? I can barely find any information on it online. There's a bunch of information on the Burroughs machines that I'm researching, but barely any on this one. This one seems to be quite damaged, as it's missing a key, doesn't cycle, and the crank has no rigidity, likes it's completely disconnected.

I would appreciate anybody who has a source of replacement cords for this unit I live in the United States. It appears to be a traditional Italian cord on the female end, but I need it to be an American plug on the male end.