Hi Dave. I’m a long time subscriber to your channel, but also the great grandson of the founder of Facit, Elof Ericsson. I’m really looking forward to seeing this video! Thanks for your great work.
So you are the grandson of Gunnar Vilhelm Ericsson? Do you have any idea if your great grandfather, Elof Ericsson, was in any way related to Lars Magnus Ericsson?
The producer of the motor, Överums Bruk AB, has actually a really long and interesting history in itself, having been around since the 17th century and made everything from farming equipment, to cannons and cannon balls, and motors. By the time this machine was made they were a wholly owned subsidiary of Facit.
Probably, but I'd think it would be insanely expensive to ship that thing all the way from Australia. It probably weighs about as much as a typewriter.
@@EEVblog Yeah, I think sending it to that John Wolff guy would be your best shot at having it restored. It would be awesome to bring the machine back to life! Curious Marc would probably love to fix it too, but shipping it all the way to California is too expensive!
My dad had an old mechanical calculator in the back of his shop when was a kid.. He replaced it with an electronic calculator when it got gunk in the gears and would occasionally spit out the wrong result.. I took it partially apart, sprayed a whole can of WD-40 into it to wash off all the congealed gunk, put it together and it worked again, but it dripped oil for months afterwards 😁 (I was something like 14 and didn't know any better).. It's still in the basement at my parents house and probably still works... Even though my degree is in computer engineering, mechanical calculators and computers completely amaze and mystify me..
@@illustriouschin WD40 works well as a cleaning solvent. Scrub with tooth brush, wipe away as much as possible, use an air compressor to blow away as much of it as possible, then re-oil generously with thin oil like sewing machine oil. Work it for a while, then wipe away most of that to avoid the oil attracting dust. For the sliding parts any thin grease will do.
I'm way to young to know much about these calculators but I have heard lots of stories about them and other Facit products from my relatives and my older colleges at both Facit (changed its name to PartnerTech about 25 years ago) and Överums Bruk (now a part of CNH Industrial). The factories in both Åtvidaberg and Överum had lots of old and intresting stuff from the years they had been around, including some traces of products made in arount 1960-1970. Really nice to see one that has found its way across the Earth :)
I just remembered that I had seen an old design sketch of this model and I still had it. i.imgur.com/UqKnd23.jpg It is signed "Bernadotte & Bjørn" 1968.
Dave, you already know how to restore it! You found John Wolff's website, and there's the information you want! Now go do your due dilligence and treat us to a video series of disassembly, repair/refurbishment and reassembly of this beautiful machine, and then show it working to us!
I'm guessing that's what the SUB/STOP button is for. I recall seeing another video demonstrating an electromechanical calculator getting stuck in a loop on a divide by zero.
Gladly made me go back in time! My father used a FACIT at home in 1964, but it had a handcrank instead of a motor. His electric calculator was a 1960 Tenkey Burroughs with a printer!
My grandpa used an much older one that only had +/- functionality until 2001 when he retired. Still remember the sound of the thing as he used it on his kitchentable every friday evening to do his accounting.
fun fact: electronic calculators do still do kinda resemble the design of their mechanical ancestors (Daves nomenclature of an accumulator and registers is very deliberately fitting)
Mechanical calculators hung on for a while after electronic ones. In the early 1980s I was working in a phone company building. Next to the break room was a room packed with hand cranked, mechanical calculators. They had a column of 0 to 9 keys for each digit position. No fancy Facit stuff. I had to ask why they still had hand cranked calculators when every one had electronic. Budget time. Electronic ones didn't have enough digits. Plus in many ways Ma Bell was hanging on to the trailing edge of technology. NYC business office was still a cord-board operation with operators plugging in phone jacks to answer calls.
@@EEVblog Maybe he would be open to come and do it in the lab so you can film it. It can be a cool video series and reference to others for future restorations. My mom has one but i think it is the hand cranked version of it.
23:50 note the 0 in the middle. The Facit made this so prominent, the 0 is still bottom center on modern keypads. Look for yourself on any modern keypad!
The zero is in the middle because it doesn't turn the pinwheel when pressed. The four keys on one side revolve the pinwheel away from. the operator, and the four on the other side revolve it toward the operator. More open pinwheel machines turn the pinwheel setting lever entirely in one direction for all numbers. This is one of the main features that allows the Facit to use keys instead of levers to set the input.
@@simonuden8450 thanks for that clarification! I have a Facit CM-13 and never realized that when restoring mine about 3 years ago. Now I've just got to open it back up to see it! Makes perfect sense though, as this pinwheel has a moving carriage.
My high-school had Facit mechanical calculators until least the mid 70s. It was interesting to hear how much noise a classroom full of these machines could make, esp when you set it up to divide the maximum number of digits, the number 9 divided by 1.
There's bookstore when I was a kid that uses similar kind of mechanical calculator, I'm always fascinated when the cashier punch and crank to get the result along with a printed receipt, I would stare and watch for a while every single time
In the 1970s while still in middle school, probably grade 6 or 7, I found a mechanical calculator at a garage sale and got my mom to buy it, probably for a dollar or two. I spent HOURS with the lid off pulling the lever slowly so I could watch how it did operations. I think it really jumpstarted me on loving mechanical stuff and logic and computers.
I wish I still had it when my kids were small; I think every kid should have the chance to play with such a thing. It's probably the best example of how things like this work - nice and big and visible. Mine had 12 rows 0-9 of keys, so very easy to understand.
Have you tried pushing the big gold pin to the side while spinning the gear? maybe it locked somehow. The fact the equals button is the only one working tells me it may have been involved in locking up the whole mechanism, Maybe someone pushed the button harder than they should have and the calculator is permanently in "equals" mode, locking up the entire mechanism.
At least it didn't explode when they turned it on that would have been bad. I've seen many of video with exploding caps the ones the metal film once it seemed to not just let out a smell but let out the stench as well.
In the 80's my dad was the manager of a department store. On the accounting room there was the hand cranked version of this calculator, not used anymore, but every time I went there as a kid I got that calculator to play and do my math homework.
I have the C1-13 mechanical model that I inherited from my dad. He used it in his work as an architect, doing static calculations and probably some ledgers. Mine still works great after all these years and there is no glitches or lockups. The sound it does as I turn the wheel is smooth and pleasing. It is different to this model. This model has divide and multiply keys and a few more that are not present in the older mechanical calculator but you can still do the four operations. Subtraction and division require reverse rotation of the crank handle. I visited Stockholm back in 2003 and we went to the technological museum. They had a calculator hall, and several FACIT calculators obviously there, for display and use by the visitors. I demonstrated its operation to our group and a small crowd soon gathered. A museum attendant soon came over and we were afraid he wanted us to stop messing with the calculator. In the contrary, he came along and asked me to demonstrate to him the operation of the calculator so he could show it to visitors. We spent 15 minutes going over the machine and it was lovely. These old calculators have some magic. They take effort (literally) to work and they make noise. Nobody would have a second look at an electronic four banger, right? BTW, if you ever visit Stockholm, don't miss the Technological museum. If you are technically inclined, you will be fascinated. And the Vasa 16th century ship museum as well. You need to see this as well. Even if you are not into modeling or ancient ships. PS. To see the machine in action, check this out: ruclips.net/video/hgV9DbfIlgg/видео.html
Hi! I live in the city where the company that was the world leader in mechanical calculators (Olivetti) in its day is based. I am passionate about company history, and in the era of the transition to electronics the old mechanical engineers were even able to set up a prototibo based on the "mechanical bit". Pure madness. Curiosity! The designer of the best-selling mechanical calculator (Divisumma 24) was a farmer who was trained by Camillo and Adriano Olivetti (the founders of the factory). He then received an honorary degree in engineering.
I have the smaller model of this calculater. It doesn't have an electrical motor, but a handle instead that can be cranked one way for addition and multiplication and the other way for subtracting and division . It was stuck like yours when I got it, but I rinsed all the mechanics with a solvent and then dried it and lubricated it with new oil. Now it works perfectly. It can add, multiply, subtract, divide and calculate square roots.
My grandmother had an old C1-13 (I think) pretty much the same, but with a hand crank on the side, but when she died, my aunt binned it as junk before I could rescue it.
Did the motor spin at all? I wouldn't be concerned about that gear stopping because there looks like a clutch that lets the motor spin. I would bet it would at least spin up. What a beauty!
Have John Wolf as a guest and fix the calculator together! That would be amazing! Maybe have a video call to go over some "first steps" to get the thing working.
Hi Dave: Great video! I guess I would not be too concerned about keys being stuck. When you pull the mains cable the gears end up in random positions and the keys may appear stuck. It takes a few rotations of the motor to bring everything into an orderly state at which the keys are all unstuck. What you might want to check first is the mechanism that you describe in 13:30 of your video. This is sort of the clock generator in modern terminology. The motor has to rotate in such a way that the dancer travels "uphill" in the curved slot, and does not block right away. The curved slot gear is mounted on a camshaft with a notch right above the motor capacitor. This gives the ticks of the clock. When the curved slot gear is stuck also in the 'right' direction, this might be root cause. Maybe it just the dancer acting up. I guess, you could remove the single e-clip on top of the dancer, take it off, and clean the curve slot (I haven't done that myself). I could send you a quick video in slow motion that explains function a lot better...Cheers+thanks.
Hello! I have a similar calculator with the exact same problem. The engine spins but the mechanics and buttons are locked. Do you have any tips on how to make the mechanics come off?
Working in a bank in the mid 80s, I used an electro-mechanical calculator like this made by Burroughs. It was a flattened version of this. When you turned it on it sounded like a tiny B-17, and hitting keys sounded like a machine gunner.
Just had a look at the website and clicked the John Wolff link at the bottom and you may have been within a few feet of him because it says he is regularly at the Puffing Billy Railway. Thought I recognized the name and found it on EEVblog2.
You may not believe me but I have actually used one of them, sometime during 1972-74. They were junked when the electronic calculators arrived (big machines with 13 nixie tubes) but we needed written permissions to use them.In FACIT, you can divide by zero and the machine will continue to run indefinitely. They were quite expensive machines. Good old days.
A "four banger" can do any calculation. If you know how to take a square root with pen & paper, you can do it on this too. It really depends how well you know your maths.
We had a Facit branded dot matrix printer in the software company where I worked in the early eighties. It was built like a tank. It printed on wide fanfold paper and had an amazing speed.
Minor point of note: That's a CA1-13, not a C1-13. The "A" stands for automatic or something and indicates that it's the motorised version with multiplication and subtraction. I have one which has addition and subtraction swappedd and is currently beyond my capabilities to debug. Most interesting thing about it to me is that multiplication is essentially "hacked" into the mechanism - it uses it's own hidden pinwheel on the underside instead of using the three visible ones. Even though it works the same as division (repeated addition) it doesn't use the main add/subtract mechanism.
Also, the buttons change mode based on the switch at the bottom. The divide button is actually subtract. The "Sub Stop" button is to stop division as it just runs continuously if you divide by zero.
My one was initially jammed like this one. You need the motor powered (it switches on and off automatically) for the keys to work and when any of the motorised operation keys are pressed it locks out the keyboard while the operation completes. The initial lock step is mostly mechanical, but unlocking it requires the motor running, so someone has probably hit a bunch of buttons with the motor off and gotten it jammed. The number keys and arrows are 100% mechanical and the mechanism for just that part is both insanely complicated and surprisingly obvious once you work out the basics of it. (The arrows move the input register left and right, effectively multiplying and dividing by 10, the arrow with dot key moves the input all the way to the left for division.) My understanding is that the oil used on them is a special now-unobtainable blend made specifically to stick to the mechanism and keep it running for a few years, but eventually gums up. They'd be serviced and re-oiled every few years normally. You need to remove all of that oil and re-oil it to get it fully operational. I understand that the enthusiast community tends to use anti-rust spray oil, even though it doesn't stick around as long as the proper oil would. You should be able to remove the motor unit by undoing a couple of big screws underneath the motor. Be aware that there's a long switch arm reaching inside on the +/- key side. The calculator is essentially 1.5 different mechanisms combined: the multiply and equals buttons control the multiplier mechanism (input -> hidden multiply register and input + hidden multiply register -> accumulator) and the rest of the keys either control the visible registers (e.g. the |, || and ||| keys clear them) or are operations performed by the "main" mechanism using the values in those registers. The behaviour of the right hand keys depends on the position of the three position control switch at the bottom left. + is always Add, but the divide key switches between subtract and divide. There's also a second tiny mode lever next to the control one, but I can't recall what it does. Divide is it's own special sort of magic: it subtracts the denominator from the numerator and effectively works like long division. However it has an optimisation where it will add instead if that requires less operations to get to zero - then do an extra subtraction somewhere else to make the math work. The CA1-13 (and ESR and ESR-0 which preceded it) were the last of their "monolithic" designs where everything was integrated together. The C2s and CA2s were more modular and had a more modern 3x4 key layout. Facit essentially ceased to exist when electronic calculators came out. Within a couple of years it went from being a massive company to a footnote, bought up and forgotten.
Dave marvels over the mechanical engineers and their skills to design something like this. I'd like to hear those designers words about those new-fangled vacuum tubes and transistors! No moving parts, how can you figure out anything?
Takes me back to 1968 when we used those in our Computer Science Numerical Methods course doing Newtonian finite element analysis! They worked though! :))
@@frankowalker4662 one of the quickest replies yet by the way and by the way thanks for letting me know what the images are from probably why I recognized it and say.
Seen the Writing on the wall ? Facit insider told that Facit QA department bought one of the electronic calculators to use it for verifying their own machines. Amaizing !
Much younger than the Machine but I did play with a manual Facit in the museum of a Bank. They are really a pleasure to use. I did not do the more sophisticated things like multiplication and division. But the ergonomics on these is great.
I think the equals key may be jammed down in the mechanism, it may very well be that the machine is designed to lockout other buttons when one is pressed
Given this has a heavy mechnical sliding component, did you check there isn't a locking lever somewhere that locks all the keys and gears down for transit? It would make a lot of sense to be able to lock the entire mechanical section for protection when moving.
Just had another idea: there are two other issues that could be at play with the keys as opposed to being gunked up. A. travel-lock/screw. B. the unit was powered off while the equals function was running leaving the gears in unworkable positions.
When I worked for the bank in the early 1980s they were still using mechanical Burroughs adding machines from the 1930s all operated by a lever. This takes it to an extreme level and I bet these were designed for serving in the field by company technicians as they were most likely very expensive and critical equipment for every business that bought one.
I agree with the suggestion others have made of bringing it to John Wolff himself since he's just in Adelaide. Maybe you two can make a collab video on tearing it down and restoring it.
I am pretty sure the return bar shown @21:40 is what's holding all the other keys locked. Looks like an operation was started but never managed to finish and return the locking bar back to the parked position.
Hi Dave. Back in the day at Uni we had Freidens and the "student" models had no motor just a knob and twirly handle, which is what lead to the notion of "cranking it out" when it came to statistics.
I do have a big fascination and respect for those designers at the time!! (Bowing) it takes a great understanding of arithmetics and numbering math laws... Besides we can also notice the inspiration for having and accumulator register in our modern processors!!
At ~10 y.o. I found hand-cranked calculator of one local manufacturer. Very dirty and rusty. Cleaned and restored it by submerging in bucket of oil & petrol "cocktail" for several days :)
Your best option would be to get in touch with your fellow Aussie. You're not the only one with the same description of the locked keyboard and or locked mechanism ON, and hear this, the mechanical and electro-mechanical variant of this unit. So he might have some kind of insight as to why the entire input side is jammed. This is not a case of lubrication gone bad nor is it a lack of it, this is likely either a mechanical error (these can get jammed if you don't follow proper procedure, my purely mechanical unit had to be walked in reverse when i did a wrong move once) or some kind of solid detritus fallen inside. It's really worth your effort to get in touch with John, especially to show the young ones, it's quite fascinating and 10 years of stewardship of my unit and i'm still pulling it out once a month to keep it in working condition.
Not sure if you can get it on the counterweight continent but Breakfree CLP does an amazing job loosening up gunky oil and such in little mechanical things like this. I'd just liberally hose it down, let it soak for a few days, and give it another try. I used to have a Monroe manual adding machine that needed some love and CLP really got it working smoothly.
Great Video !! Love your channel - served as a Missionary in Sydney back in 1978, I'm an Electronics tech: EET although most of my Adult life have worked on Photocopiers and Laser Printers ... when I was 18, 19 years old I worked on the old NCR mechanical cash registers, My boss at the time the NCR accounting machines ( Huge ) they had to be kept oiled and lubed to add properly .... racks and rack of gear teeth and gears ! we had Cash Registers that 20 departments and could keep track of that many departments at the old Kmart stores ... amazing what people think up !!
I'd say it's normal that the motor doesn't run when it's idle, the hand-cranked ones also don't require your to turn the handle all the time. Have you tried the keys when it's powered up?
The power goes to the motor directly unswitched. The motor provides constant energy to a flywheel, that acts as an energy accumulator, and is clutched in for operations.
P.S "AB Överums bruk" = Överum is a city, Bruk rougly translates to factory and AB is the same thing as Ltd. In other words it was made in another factory in Överum, Sweden. According to wikipedia, that factory actually started in the very early 1800s.
I don't even know where I would start designing something like this, not only making sure it works, but that the parts are manufacturable, then to actually design the manufacturing process. I imagine lot of it would have been somewhat manual, but still. Crazy to think the engineering and work that went into it.
Let's hope that Rifa cap isn't a relative of their X2 rated mains caps that like to release the magic smoke. There looks to be enough smoke in that one to set your building's fire alarm off ;-)
Back in the day, typewriter repairmen were all over the place, and this thing would be right up their alley. It's somewhat more complicated than a manual typewriter, but not hideously so. The main thing in there is the the gear train that is just a basically a 10:1 reduction. As I recall that was accomplished using a single tooth cog, that allowed the next higher digit to be advanced by other components. That particular one is extra complex, since internally there is a sliding carriage that allows you to set multiple digits using the same keys. The older machines had a 1-9 column of keys for each position, which made the internals simpler. Noise-wise, these were about the same as a ASR-33 teletype. The crank just plugged into the same shaft as the motor.
My father brought home a mechanical payroll calculator / printer from NCR - it was enormous! It was on a cast metal stand like a desk, had a typewriter part and a mechanical calculator/totaliser part on the keyboard. The operator would type out the employee name, with a line description and then the hours worked and the correct rate, plus over time, minus any union dues or expenses and the machine WOULD CALCULATE THE TOTAL. All entirely mechanically. It had thousands of parts, dozens of motors and smelt like an oil refinery!
6:20 I don't think the keys will work unless the drive motor is turning. Often, a cam will keep an activation lever locked out until a certain phase of rotation of a larger mechanism
Used one of the manual versions for surveying calcs at Uni in early 70's. Used with 7 figure log tables. I bought a couple of the manual versions many years ago and am always fascinated by their operation. It is amazing to see how to the manual ones operate for multiplication and division. You are basically doing successive additions or subtraction depending on which way you crank the handle. It may not be the ideal way to keep them operating - I give them a good spray with WD40. It has kept them going all these years.
It seems to be a locking bar in place to block concurrent key presses, I think I remember that it was the case that when a key was pressed all others were blocked until the motor had executed one turn of the mechanics to process that key press. I have fiddled with one when I was like 4 or 5 years old and it was shockingly noisy for me at the time.
17:54 the keys all seem to have a locking latch that holds it from being depressed (presumably while an operation is in progress to stop you mucking about). If you can find the bar/cam that nudges those locks I bet the keys become functional.
addendum: not posting a 'duh that's the problem' moment - just that it helps to work backwards to find the jam...like finding the stuck hammers on an old typewriter - you can't tell the problem from the keys so you have to work forward in that direction.
I think the zero is just there in the middle for easier/faster use. I assume you use the numpad single handed and the zero is a quite frequently occurring number
The lesson I've been thought from Facit is that you should never reject new technology. Facit were probably the best in the world on making mechanical calculator, so they didn't see the need to change when new technology came about. Just a few years after the entry of the electronic calculators, the company was gone.
Curious Marc restored a similar Facit calculator and published a play list at his channel. Maybe you can ask him (and make a crossover video with him).
Was using one of these in hardware store I worked at in 1987 it was the hand cranked type. We used to play game on them trying to turn the hand crank the most revolutions in one go. They are built like a Tank and almost unbreakable. (playing games on them can break the handle)
Can anyone else imagine non-Dave looking a circuit board and going " and this trace links to this hole and it goes underneath, and this wire linksto that trace and they all keep going to this bits with legs and it's covered in these black squares? It's silly, it's just insane!"
Its all what your used to thinking/working with. got an ol boy in the workshop, career mechanic, but got out of the game when it all started getting 100% computerised. I think he's electron-phobic, which is a little annoying in an electronic engineering shop, but he's a demon with a wrench. and an awful lot of custom electronic stuff actually boils down to the chassis/mounting/bracketry etc, so he's handy to have around. anyway, he's still got a good brain, and if you can convert whats happening to a mechanical analogy, he can understand quite alot. there are an awful lot of parallels. one thing I do really like about our shop is its perfectly acceptable to stop for 10 minutes to explain whats going on to a colleague, even if its none of their business. Its seen as a benefit that everyone from the firmware codemonkey to the metalbasher has a decent overview of the project. your not just in your little box, solving your little problem, ignoring everything else. Its everyones, and if it *all* dosent work, well, none of us get paid. it garners respect between the various departments, and can really help if you have a hit a roadblock to get a completely different perspective. it might not be 100% right, but gets you looking at a problem from a different direction. I would LOVE to see the melding of minds of Dave and John working together on this, the lightbulb moments where Dave realises 'ooh, these levers and that cam are like a flipflop! theres you set, theres you latch, and this is the clock! Wow!'
To be honest, I have almost exactly the same feeling when I look at internal schematics for ICs, found in some datasheets for old opamps, lm317-s and such. It gets easier when you learn some typical contraptions, such as "this is a current source", "this is a current mirror", "this is a differential stage", "this is a bandgap reference"... I guess, mechanical enginerds had their building-block library in their minds, too.
unless the negate key negates the contents of the accumulator. but yes if not that would be a perfectly valid way to do things and some processors today dont have circuitry for that very reason (they do negation and addition internally)
The logic within such a machine was secondary to it's internal complexity. The electrical engineer made the mechanical engineer obsolete in this field.
I have a full mechanical calculator, I tried for days trying my very best to get it working, in the end, I decided parts must be worn out, and now its a block of metal in the lounge, really nice condition Multo Mechanical calculator.
Way back whenever, there were a lot of adding machines with hundreds of buttons on the entry area., I looked inside them and they looked similar internally.
You could try a can of brake or carb cleaner, or lighter petrol will also soften the greas but I suspect that something has jumped out of place, you could try pushing that lever that follows the face cam over while turning the motor by hand.
![Felix "Unfair" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/Oswujxm2Ag0/mqdefault.jpg)
Hi Dave. I’m a long time subscriber to your channel, but also the great grandson of the founder of Facit, Elof Ericsson. I’m really looking forward to seeing this video! Thanks for your great work.
Yes
Can you tear it down for us? Make your great grandfather proud!
Alex Roge My track record is really bad. You’ll end up with a bucket of cogs and bearings.
Scammed KEKW
So you are the grandson of Gunnar Vilhelm Ericsson? Do you have any idea if your great grandfather, Elof Ericsson, was in any way related to Lars Magnus Ericsson?
The producer of the motor, Överums Bruk AB, has actually a really long and interesting history in itself, having been around since the 17th century and made everything from farming equipment, to cannons and cannon balls, and motors. By the time this machine was made they were a wholly owned subsidiary of Facit.
It's watch making science, imagine doing the same thing with tiny pieces.
ruclips.net/video/WofWNcMHcl0/видео.html
You might check with CuriousMarc. I could see him being interested in restoring it.
Probably, but I'd think it would be insanely expensive to ship that thing all the way from Australia. It probably weighs about as much as a typewriter.
@@ct6502c more
@@ct6502c 13kg. Would cost maybe $200 to ship.
@@EEVblog Yeah, I think sending it to that John Wolff guy would be your best shot at having it restored. It would be awesome to bring the machine back to life! Curious Marc would probably love to fix it too, but shipping it all the way to California is too expensive!
@@ct6502c but Marc could give him pointers and/or videochat guide him without shipping needed
Curiosmarc would be interested.
yet another project for him to rip apart !
@@moonsengineeringadventures623 and fix and put back together!
I fear he messes it up... 👻
@@blenderbuch Did you see what he did with the teletype? After a series of like 25 videos it finally worked OK.
I know I meant Dave 😁😂
...Dave accidentally brings down the guy’s website as 500k nerds check out the mechanical calculator overhaul!
Old Slashdot humor: downed site must have been running on a mechanical calculator.
Not Maximum Overdrive although in this case it could be at least maximum driven.
But in case of the website maximum overload.
Dang I missed it the calculator means maximum overhaul.
My dad had an old mechanical calculator in the back of his shop when was a kid.. He replaced it with an electronic calculator when it got gunk in the gears and would occasionally spit out the wrong result.. I took it partially apart, sprayed a whole can of WD-40 into it to wash off all the congealed gunk, put it together and it worked again, but it dripped oil for months afterwards 😁 (I was something like 14 and didn't know any better).. It's still in the basement at my parents house and probably still works... Even though my degree is in computer engineering, mechanical calculators and computers completely amaze and mystify me..
it might need another can of WD40 again though!
WD-40 will turn into a nasty gunky mess after a while.
@@illustriouschin it's already had a whole can of it sprayed in though!
@@illustriouschin WD40 works well as a cleaning solvent. Scrub with tooth brush, wipe away as much as possible, use an air compressor to blow away as much of it as possible, then re-oil generously with thin oil like sewing machine oil. Work it for a while, then wipe away most of that to avoid the oil attracting dust.
For the sliding parts any thin grease will do.
The mechanical engineering in things like this is amazing.
Can smell the 60s gear metal and oils from here.
yup!
Don’t forget mixed with 60 year old dust. 😅
@@ibanezleftyclub stop now. I'm getting excited with all these memories flooding back 🤣
Mmmmm...the asbestos insulation...
I'm way to young to know much about these calculators but I have heard lots of stories about them and other Facit products from my relatives and my older colleges at both Facit (changed its name to PartnerTech about 25 years ago) and Överums Bruk (now a part of CNH Industrial). The factories in both Åtvidaberg and Överum had lots of old and intresting stuff from the years they had been around, including some traces of products made in arount 1960-1970.
Really nice to see one that has found its way across the Earth :)
I just remembered that I had seen an old design sketch of this model and I still had it.
i.imgur.com/UqKnd23.jpg
It is signed "Bernadotte & Bjørn" 1968.
Dave, you already know how to restore it! You found John Wolff's website, and there's the information you want! Now go do your due dilligence and treat us to a video series of disassembly, repair/refurbishment and reassembly of this beautiful machine, and then show it working to us!
Maybe someone Divided by Zero and locked it up .
Hey, that's a great idea.
I'm guessing that's what the SUB/STOP button is for. I recall seeing another video demonstrating an electromechanical calculator getting stuck in a loop on a divide by zero.
Xor, best gate
"This is what happens when you divide by zero on a mechanical calculator" ruclips.net/video/OFJUYFlSYsM/видео.html
"CuriousMarc - Divide by Zero on the Friden STW10 Mechanical Calculator" ruclips.net/video/7Kd3R_RlXgc/видео.html
Gladly made me go back in time! My father used a FACIT at home in 1964, but it had a handcrank instead of a motor. His electric calculator was a 1960 Tenkey Burroughs with a printer!
My grandpa used an much older one that only had +/- functionality until 2001 when he retired. Still remember the sound of the thing as he used it on his kitchentable every friday evening to do his accounting.
fun fact: electronic calculators do still do kinda resemble the design of their mechanical ancestors (Daves nomenclature of an accumulator and registers is very deliberately fitting)
This is pure gold, real engineers got goosebumps, for sure.
Mechanical calculators hung on for a while after electronic ones. In the early 1980s I was working in a phone company building. Next to the break room was a room packed with hand cranked, mechanical calculators. They had a column of 0 to 9 keys for each digit position. No fancy Facit stuff. I had to ask why they still had hand cranked calculators when every one had electronic. Budget time. Electronic ones didn't have enough digits. Plus in many ways Ma Bell was hanging on to the trailing edge of technology. NYC business office was still a cord-board operation with operators plugging in phone jacks to answer calls.
You should pay John Wolff to refurbish it
Not a bad idea!
Please do. He could do a video about it, and we can all marvel about how it works inside.
@@EEVblog you should see if john wolff would be interested in repairing it and you narrate the repair, should be good for a few more vids
@@EEVblog Maybe he would be open to come and do it in the lab so you can film it. It can be a cool video series and reference to others for future restorations. My mom has one but i think it is the hand cranked version of it.
John should be invited to do a Part 2 of this video. Explaining all about it.
23:50 note the 0 in the middle. The Facit made this so prominent, the 0 is still bottom center on modern keypads. Look for yourself on any modern keypad!
The zero is in the middle because it doesn't turn the pinwheel when pressed. The four keys on one side revolve the pinwheel away from. the operator, and the four on the other side revolve it toward the operator. More open pinwheel machines turn the pinwheel setting lever entirely in one direction for all numbers. This is one of the main features that allows the Facit to use keys instead of levers to set the input.
@@simonuden8450 thanks for that clarification! I have a Facit CM-13 and never realized that when restoring mine about 3 years ago. Now I've just got to open it back up to see it! Makes perfect sense though, as this pinwheel has a moving carriage.
For some more mechanical fun, look into totalisators. Some of these were race-track sized, with tentacles reaching to all the ticket selling booths.
cool...always interesting to see how old stuff was done...
thanks for the partial teardown Dave...more stuff of this vintage plz!!
The sub stop is to stop division. They would whirl and click on and on. The neg button is used for subtraction.
My high-school had Facit mechanical calculators until least the mid 70s.
It was interesting to hear how much noise a classroom full of these machines could make, esp when you set it up to divide the maximum number of digits, the number 9 divided by 1.
Don't be shy Dave, its only 286 steps to tear it down, clean it up and get it working
There's bookstore when I was a kid that uses similar kind of mechanical calculator, I'm always fascinated when the cashier punch and crank to get the result along with a printed receipt, I would stare and watch for a while every single time
In the 1970s while still in middle school, probably grade 6 or 7, I found a mechanical calculator at a garage sale and got my mom to buy it, probably for a dollar or two. I spent HOURS with the lid off pulling the lever slowly so I could watch how it did operations. I think it really jumpstarted me on loving mechanical stuff and logic and computers.
I wish I still had it when my kids were small; I think every kid should have the chance to play with such a thing. It's probably the best example of how things like this work - nice and big and visible. Mine had 12 rows 0-9 of keys, so very easy to understand.
Have you tried pushing the big gold pin to the side while spinning the gear? maybe it locked somehow. The fact the equals button is the only one working tells me it may have been involved in locking up the whole mechanism, Maybe someone pushed the button harder than they should have and the calculator is permanently in "equals" mode, locking up the entire mechanism.
Welcome to the MEVBlog
At least it didn't explode when they turned it on that would have been bad.
I've seen many of video with exploding caps the ones the metal film once it seemed to not just let out a smell but let out the stench as well.
In the 80's my dad was the manager of a department store. On the accounting room there was the hand cranked version of this calculator, not used anymore, but every time I went there as a kid I got that calculator to play and do my math homework.
Oops closure should be collector.
I have the C1-13 mechanical model that I inherited from my dad. He used it in his work as an architect, doing static calculations and probably some ledgers. Mine still works great after all these years and there is no glitches or lockups. The sound it does as I turn the wheel is smooth and pleasing. It is different to this model. This model has divide and multiply keys and a few more that are not present in the older mechanical calculator but you can still do the four operations. Subtraction and division require reverse rotation of the crank handle.
I visited Stockholm back in 2003 and we went to the technological museum. They had a calculator hall, and several FACIT calculators obviously there, for display and use by the visitors. I demonstrated its operation to our group and a small crowd soon gathered. A museum attendant soon came over and we were afraid he wanted us to stop messing with the calculator. In the contrary, he came along and asked me to demonstrate to him the operation of the calculator so he could show it to visitors. We spent 15 minutes going over the machine and it was lovely. These old calculators have some magic. They take effort (literally) to work and they make noise. Nobody would have a second look at an electronic four banger, right?
BTW, if you ever visit Stockholm, don't miss the Technological museum. If you are technically inclined, you will be fascinated. And the Vasa 16th century ship museum as well. You need to see this as well. Even if you are not into modeling or ancient ships.
PS. To see the machine in action, check this out: ruclips.net/video/hgV9DbfIlgg/видео.html
Hi! I live in the city where the company that was the world leader in mechanical calculators (Olivetti) in its day is based. I am passionate about company history, and in the era of the transition to electronics the old mechanical engineers were even able to set up a prototibo based on the "mechanical bit". Pure madness. Curiosity! The designer of the best-selling mechanical calculator (Divisumma 24) was a farmer who was trained by Camillo and Adriano Olivetti (the founders of the factory). He then received an honorary degree in engineering.
I have the smaller model of this calculater. It doesn't have an electrical motor, but a handle instead that can be cranked one way for addition and multiplication and the other way for subtracting and division . It was stuck like yours when I got it, but I rinsed all the mechanics with a solvent and then dried it and lubricated it with new oil. Now it works perfectly. It can add, multiply, subtract, divide and calculate square roots.
My grandmother had an old C1-13 (I think) pretty much the same, but with a hand crank on the side, but when she died, my aunt binned it as junk before I could rescue it.
Did the motor spin at all? I wouldn't be concerned about that gear stopping because there looks like a clutch that lets the motor spin. I would bet it would at least spin up. What a beauty!
Have John Wolf as a guest and fix the calculator together! That would be amazing! Maybe have a video call to go over some "first steps" to get the thing working.
Hi Dave: Great video! I guess I would not be too concerned about keys being stuck. When you pull the mains cable the gears end up in random positions and the keys may appear stuck. It takes a few rotations of the motor to bring everything into an orderly state at which the keys are all unstuck.
What you might want to check first is the mechanism that you describe in 13:30 of your video. This is sort of the clock generator in modern terminology. The motor has to rotate in such a way that the dancer travels "uphill" in the curved slot, and does not block right away. The curved slot gear is mounted on a camshaft with a notch right above the motor capacitor. This gives the ticks of the clock.
When the curved slot gear is stuck also in the 'right' direction, this might be root cause. Maybe it just the dancer acting up. I guess, you could remove the single e-clip on top of the dancer, take it off, and clean the curve slot (I haven't done that myself). I could send you a quick video in slow motion that explains function a lot better...Cheers+thanks.
Hello! I have a similar calculator with the exact same problem. The engine spins but the mechanics and buttons are locked. Do you have any tips on how to make the mechanics come off?
Working in a bank in the mid 80s, I used an electro-mechanical calculator like this made by Burroughs. It was a flattened version of this. When you turned it on it sounded like a tiny B-17, and hitting keys sounded like a machine gunner.
Just had a look at the website and clicked the John Wolff link at the bottom and you may have been within a few feet of him because it says he is regularly at the Puffing Billy Railway. Thought I recognized the name and found it on EEVblog2.
You may not believe me but I have actually used one of them, sometime during 1972-74. They were junked when the electronic calculators arrived (big machines with 13 nixie tubes) but we needed written permissions to use them.In FACIT, you can divide by zero and the machine will continue to run indefinitely. They were quite expensive machines. Good old days.
A "four banger" can do any calculation. If you know how to take a square root with pen & paper, you can do it on this too. It really depends how well you know your maths.
We had a Facit branded dot matrix printer in the software company where I worked in the early eighties.
It was built like a tank. It printed on wide fanfold paper and had an amazing speed.
Minor point of note: That's a CA1-13, not a C1-13. The "A" stands for automatic or something and indicates that it's the motorised version with multiplication and subtraction.
I have one which has addition and subtraction swappedd and is currently beyond my capabilities to debug.
Most interesting thing about it to me is that multiplication is essentially "hacked" into the mechanism - it uses it's own hidden pinwheel on the underside instead of using the three visible ones. Even though it works the same as division (repeated addition) it doesn't use the main add/subtract mechanism.
Also, the buttons change mode based on the switch at the bottom. The divide button is actually subtract. The "Sub Stop" button is to stop division as it just runs continuously if you divide by zero.
There should also be a bottom plate you can take off. They're even more fascinating from the bottom!
My one was initially jammed like this one. You need the motor powered (it switches on and off automatically) for the keys to work and when any of the motorised operation keys are pressed it locks out the keyboard while the operation completes. The initial lock step is mostly mechanical, but unlocking it requires the motor running, so someone has probably hit a bunch of buttons with the motor off and gotten it jammed.
The number keys and arrows are 100% mechanical and the mechanism for just that part is both insanely complicated and surprisingly obvious once you work out the basics of it. (The arrows move the input register left and right, effectively multiplying and dividing by 10, the arrow with dot key moves the input all the way to the left for division.)
My understanding is that the oil used on them is a special now-unobtainable blend made specifically to stick to the mechanism and keep it running for a few years, but eventually gums up. They'd be serviced and re-oiled every few years normally. You need to remove all of that oil and re-oil it to get it fully operational. I understand that the enthusiast community tends to use anti-rust spray oil, even though it doesn't stick around as long as the proper oil would.
You should be able to remove the motor unit by undoing a couple of big screws underneath the motor. Be aware that there's a long switch arm reaching inside on the +/- key side.
The calculator is essentially 1.5 different mechanisms combined: the multiply and equals buttons control the multiplier mechanism (input -> hidden multiply register and input + hidden multiply register -> accumulator) and the rest of the keys either control the visible registers (e.g. the |, || and ||| keys clear them) or are operations performed by the "main" mechanism using the values in those registers. The behaviour of the right hand keys depends on the position of the three position control switch at the bottom left. + is always Add, but the divide key switches between subtract and divide. There's also a second tiny mode lever next to the control one, but I can't recall what it does.
Divide is it's own special sort of magic: it subtracts the denominator from the numerator and effectively works like long division. However it has an optimisation where it will add instead if that requires less operations to get to zero - then do an extra subtraction somewhere else to make the math work.
The CA1-13 (and ESR and ESR-0 which preceded it) were the last of their "monolithic" designs where everything was integrated together. The C2s and CA2s were more modular and had a more modern 3x4 key layout.
Facit essentially ceased to exist when electronic calculators came out. Within a couple of years it went from being a massive company to a footnote, bought up and forgotten.
Dave marvels over the mechanical engineers and their skills to design something like this. I'd like to hear those designers words about those new-fangled vacuum tubes and transistors! No moving parts, how can you figure out anything?
Takes me back to 1968 when we used those in our Computer Science Numerical Methods course doing Newtonian finite element analysis! They worked though! :))
I love the mechanics in these old pieces of tech. I could study it for decades and be non the wiser on how it works. :)
By the way what's the user image from? Please comment.
@@aaronbrandenburg2441 It's Ziggy, from a ZX Specrum game called The Pyramid. I lost most of the 80's to this game.
@@frankowalker4662 one of the quickest replies yet by the way and by the way thanks for letting me know what the images are from probably why I recognized it and say.
Seen the Writing on the wall ? Facit insider told that Facit QA department bought one of the electronic calculators to use it for verifying their own machines. Amaizing !
Firmware upgrade is a new set of cams.
Much younger than the Machine but I did play with a manual Facit in the museum of a Bank. They are really a pleasure to use. I did not do the more sophisticated things like multiplication and division. But the ergonomics on these is great.
Dave, looks like the top has a maniacal interlock to prevent an accidental operation with the cover off.
The audio crackle/distortion each time it was plugged in... oof
I think the equals key may be jammed down in the mechanism, it may very well be that the machine is designed to lockout other buttons when one is pressed
If you hear the sound of shredding paper, its me tearing up my mechanical engineering degree. I'm out!
I'd wager most of the people alive today who used these machines haven't got grey beards
Given this has a heavy mechnical sliding component, did you check there isn't a locking lever somewhere that locks all the keys and gears down for transit? It would make a lot of sense to be able to lock the entire mechanical section for protection when moving.
Just had another idea:
there are two other issues that could be at play with the keys as opposed to being gunked up.
A. travel-lock/screw.
B. the unit was powered off while the equals function was running leaving the gears in unworkable positions.
I had the manually cranked one as a kid in the 80's. I was amazed by the mechanics of it and I still don't understand how the thing worked.
When I worked for the bank in the early 1980s they were still using mechanical Burroughs adding machines from the 1930s all operated by a lever. This takes it to an extreme level and I bet these were designed for serving in the field by company technicians as they were most likely very expensive and critical equipment for every business that bought one.
I agree with the suggestion others have made of bringing it to John Wolff himself since he's just in Adelaide. Maybe you two can make a collab video on tearing it down and restoring it.
I am pretty sure the return bar shown @21:40 is what's holding all the other keys locked. Looks like an operation was started but never managed to finish and return the locking bar back to the parked position.
Hi Dave. Back in the day at Uni we had Freidens and the "student" models had no motor just a knob and twirly handle, which is what lead to the notion of "cranking it out" when it came to statistics.
I always wondered what that meant in terms of where it came from!
Used to have a couple of Olivetti Prima 20s and a variety Predecimal Lsd (UK Currency) accounting machines.
I absolutely adored them.
I do have a big fascination and respect for those designers at the time!! (Bowing) it takes a great understanding of arithmetics and numbering math laws... Besides we can also notice the inspiration for having and accumulator register in our modern processors!!
At ~10 y.o. I found hand-cranked calculator of one local manufacturer. Very dirty and rusty. Cleaned and restored it by submerging in bucket of oil & petrol "cocktail" for several days :)
Your best option would be to get in touch with your fellow Aussie. You're not the only one with the same description of the locked keyboard and or locked mechanism ON, and hear this, the mechanical and electro-mechanical variant of this unit. So he might have some kind of insight as to why the entire input side is jammed. This is not a case of lubrication gone bad nor is it a lack of it, this is likely either a mechanical error (these can get jammed if you don't follow proper procedure, my purely mechanical unit had to be walked in reverse when i did a wrong move once) or some kind of solid detritus fallen inside.
It's really worth your effort to get in touch with John, especially to show the young ones, it's quite fascinating and 10 years of stewardship of my unit and i'm still pulling it out once a month to keep it in working condition.
Not sure if you can get it on the counterweight continent but Breakfree CLP does an amazing job loosening up gunky oil and such in little mechanical things like this. I'd just liberally hose it down, let it soak for a few days, and give it another try. I used to have a Monroe manual adding machine that needed some love and CLP really got it working smoothly.
Great Video !! Love your channel - served as a Missionary in Sydney back in 1978, I'm an Electronics tech: EET although most of my Adult life have worked on Photocopiers and Laser Printers ... when I was 18, 19 years old I worked on the old NCR mechanical cash registers, My boss at the time the NCR accounting machines ( Huge ) they had to be kept oiled and lubed to add properly .... racks and rack of gear teeth and gears ! we had Cash Registers that 20 departments and could keep track of that many departments at the old Kmart stores ... amazing what people think up !!
I'd say it's normal that the motor doesn't run when it's idle, the hand-cranked ones also don't require your to turn the handle all the time. Have you tried the keys when it's powered up?
The power goes to the motor directly unswitched. The motor provides constant energy to a flywheel, that acts as an energy accumulator, and is clutched in for operations.
Looks like this kind of tech may make a brief comeback for future Venus missions.
Hello from Sweden. Facit actually translates to something in the lines of "answer sheet" from when you have exams or even just math assignments.
P.S "AB Överums bruk" = Överum is a city, Bruk rougly translates to factory and AB is the same thing as Ltd. In other words it was made in another factory in Överum, Sweden.
According to wikipedia, that factory actually started in the very early 1800s.
Funny how I just got notification of this video. Three days later!.
I don't even know where I would start designing something like this, not only making sure it works, but that the parts are manufacturable, then to actually design the manufacturing process. I imagine lot of it would have been somewhat manual, but still. Crazy to think the engineering and work that went into it.
Zero in the center minimises the maximum distance from any digit to zero.
Yep that's what I was thinking.
Let's hope that Rifa cap isn't a relative of their X2 rated mains caps that like to release the magic smoke. There looks to be enough smoke in that one to set your building's fire alarm off ;-)
This belongs in a museum, this is a fantastic demonstration of history at it's best.
you watch one mechanical calculator youtube video (this one) and suddenly youtube thinks you're interested in all mechanical calculators
Had a couple of those in our University labs...some of that equipment dated way back...
That lever in the groove (13:00) on the top right of the machine swings right-left during operation:
ruclips.net/video/OFJUYFlSYsM/видео.html
Back in the day, typewriter repairmen were all over the place, and this thing would be right up their alley. It's somewhat more complicated than a manual typewriter, but not hideously so. The main thing in there is the the gear train that is just a basically a 10:1 reduction. As I recall that was accomplished using a single tooth cog, that allowed the next higher digit to be advanced by other components. That particular one is extra complex, since internally there is a sliding carriage that allows you to set multiple digits using the same keys. The older machines had a 1-9 column of keys for each position, which made the internals simpler.
Noise-wise, these were about the same as a ASR-33 teletype. The crank just plugged into the same shaft as the motor.
So basically, this is what something a watch-maker would end up doing if he was asked to design a mechanical calculator.
My father brought home a mechanical payroll calculator / printer from NCR - it was enormous! It was on a cast metal stand like a desk, had a typewriter part and a mechanical calculator/totaliser part on the keyboard. The operator would type out the employee name, with a line description and then the hours worked and the correct rate, plus over time, minus any union dues or expenses and the machine WOULD CALCULATE THE TOTAL. All entirely mechanically. It had thousands of parts, dozens of motors and smelt like an oil refinery!
It was a retired device from the local electricity company.
6:20 I don't think the keys will work unless the drive motor is turning. Often, a cam will keep an activation lever locked out until a certain phase of rotation of a larger mechanism
Used one of the manual versions for surveying calcs at Uni in early 70's. Used with 7 figure log tables. I bought a couple of the manual versions many years ago and am always fascinated by their operation. It is amazing to see how to the manual ones operate for multiplication and division. You are basically doing successive additions or subtraction depending on which way you crank the handle.
It may not be the ideal way to keep them operating - I give them a good spray with WD40. It has kept them going all these years.
Get this John bloke on the show for a collab!
It seems to be a locking bar in place to block concurrent key presses, I think I remember that it was the case that when a key was pressed all others were blocked until the motor had executed one turn of the mechanics to process that key press. I have fiddled with one when I was like 4 or 5 years old and it was shockingly noisy for me at the time.
17:54 the keys all seem to have a locking latch that holds it from being depressed (presumably while an operation is in progress to stop you mucking about). If you can find the bar/cam that nudges those locks I bet the keys become functional.
addendum: not posting a 'duh that's the problem' moment - just that it helps to work backwards to find the jam...like finding the stuck hammers on an old typewriter - you can't tell the problem from the keys so you have to work forward in that direction.
I think the zero is just there in the middle for easier/faster use. I assume you use the numpad single handed and the zero is a quite frequently occurring number
I am just in awe of Mr. Wolf's effort. The things a nerd would do. We should all try to be like Mr Wolf.
The lesson I've been thought from Facit is that you should never reject new technology. Facit were probably the best in the world on making mechanical calculator, so they didn't see the need to change when new technology came about. Just a few years after the entry of the electronic calculators, the company was gone.
Curious Marc restored a similar Facit calculator and published a play list at his channel. Maybe you can ask him (and make a crossover video with him).
absolutely. He restored teltypes as well and much more
@@_hackwell And an Apollo lunar computer! 😸🤖🤓
@@DIY-valvular yep and they made it work ! fabulous work on the core memory
Was using one of these in hardware store I worked at in 1987 it was the hand cranked type. We used to play game on them trying to turn the hand crank the most revolutions in one go. They are built like a Tank and almost unbreakable. (playing games on them can break the handle)
Can anyone else imagine non-Dave looking a circuit board and going " and this trace links to this hole and it goes underneath, and this wire linksto that trace and they all keep going to this bits with legs and it's covered in these black squares? It's silly, it's just insane!"
Its all what your used to thinking/working with. got an ol boy in the workshop, career mechanic, but got out of the game when it all started getting 100% computerised. I think he's electron-phobic, which is a little annoying in an electronic engineering shop, but he's a demon with a wrench. and an awful lot of custom electronic stuff actually boils down to the chassis/mounting/bracketry etc, so he's handy to have around. anyway, he's still got a good brain, and if you can convert whats happening to a mechanical analogy, he can understand quite alot. there are an awful lot of parallels.
one thing I do really like about our shop is its perfectly acceptable to stop for 10 minutes to explain whats going on to a colleague, even if its none of their business. Its seen as a benefit that everyone from the firmware codemonkey to the metalbasher has a decent overview of the project. your not just in your little box, solving your little problem, ignoring everything else. Its everyones, and if it *all* dosent work, well, none of us get paid. it garners respect between the various departments, and can really help if you have a hit a roadblock to get a completely different perspective. it might not be 100% right, but gets you looking at a problem from a different direction.
I would LOVE to see the melding of minds of Dave and John working together on this, the lightbulb moments where Dave realises 'ooh, these levers and that cam are like a flipflop! theres you set, theres you latch, and this is the clock! Wow!'
To be honest, I have almost exactly the same feeling when I look at internal schematics for ICs, found in some datasheets for old opamps, lm317-s and such. It gets easier when you learn some typical contraptions, such as "this is a current source", "this is a current mirror", "this is a differential stage", "this is a bandgap reference"... I guess, mechanical enginerds had their building-block library in their minds, too.
It all made me wonder, if some nerds have made a verilog/vhdl to mechanism compiler already?...
Piece of art beautiful 😍
Everyone laughs now, but if a nuclear bomb droped and destroyed all electronics, Dave's seized calculator is what we would all be fighting to use.
Sure, but what are you gonna plug it in to?
Check out Tech Tangents, Shelby has many mechanical calculators from the era and they get MUCH smaller than this.
You can subtract by negating the number and then adding it :P
unless the negate key negates the contents of the accumulator. but yes if not that would be a perfectly valid way to do things and some processors today dont have circuitry for that very reason (they do negation and addition internally)
@@urugulu1656 in that case you could just negate again
@@efa666 ah i see more points of failure equals more better ha?
The logic within such a machine was secondary to it's internal complexity. The electrical engineer made the mechanical engineer obsolete in this field.
I would love to see you overhauling that thing ,in detail
I wouldn't have the time and patience.
@@EEVblog underestandable , have a great day
I have a full mechanical calculator, I tried for days trying my very best to get it working, in the end, I decided parts must be worn out, and now its a block of metal in the lounge, really nice condition Multo Mechanical calculator.
Way back whenever, there were a lot of adding machines with hundreds of buttons on the entry area., I looked inside them and they looked similar internally.
So if you make it spin faster is that considered overclocking?
YES!
You could try a can of brake or carb cleaner, or lighter petrol will also soften the greas but I suspect that something has jumped out of place, you could try pushing that lever that follows the face cam over while turning the motor by hand.