Vintage computer repair and pcb reproductions plus discrete component computer kits. Current projects include the AGC (Apollo Guidance Computer) transistor level recreation and transistor based microprocessor kits. Examples of the vintage boards are MK14, Mark8, Altair 8800, Fluke 9010a pods, OP-80 tape reader plus many more. Videos will be posted to describe and demonstrate these. Additional material will consist of vintage valve equipment restoration.
Jerry, this has been a fascinating series. Thank you very much for your detailed explanations! Please do make another video where you put it through its paces!
Perhaps for the number labels, you could use a Brother P-Touch printer? I have a desktop Brother device that's intended to only be used with a computer and client program that runs on Windows and macOS. What's handy with this device and software is the ability to scale text (and graphics) to arbitrary sizes. And there is tape that prints white text on a black background. If you happen to have one of these devices around (or the versions with a keyboard and computer interface), it might be worth investigating. Nice work, I look forward to seeing how the 2x sized version turns out! Thanks for sharing this journey.
I tried this, but it doesn't look that great due to the overhangs on the debossed digits. Cleaning the up before infilling with paint helps a bit. You can see a partially cleaned up one in ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-JpetLE5apzM.html&ab_channel=DavidElworthy.
Could please explain which chip on the board the text on the screen represent? When you do ram shorts and plug in a range, exactly which chip on the board is it referring to? Also..if it comes back for example FF error...what is that? is FF equal 1111 1111??? So FF = one byte of all 8 bits value of 1's??? I just dont understand how to read the results of the display with it comes back with a bit error. It tells me theres a bit error..but how do i find that exact bit on the board?!?!
What an amazing project. Thank you for taking the time to document the process and for your detailed explanations of its assembly. I am curious about the choice of material used, was there any specific reason for using PLA for this project rather than some other type? Regards, David
This machine is a thing of beauty - thank you for showing your build and debug. It also showcases that it really is possible to produce something quite complex with 3D printed parts, along with your tips on how to ensure smooth running when assembled. I’ve rather enjoyed this series 😊
What a wonderful result. I'm amazed at how easily the crank turns; not even needing to hold the body of the calculator. It seems all that finishing work has really paid off in the result. The Curta is such a mechanical marvel on its own; and again the translation into the 3D printed version.
Yeah, dry PTFE is such an excellent lubricant, especially for plastic parts. I think the most successful application for me has been the pull-out trays in my bedroom wardrobe. They're made from some type of plastic and they have plastic rails/channels on the sides and the tray slides in those. Good lord how much stiction they had when I moved here. They weren't visibly dirty nor did I see any detritus on paper when I wiped them. Just too much friction. Few squirts of dry PTFE and they slide like a dream. 4½ years later I can still move them with my pinky with clothes on top of the trays. Which I think is fairly impressive considering the contact area is like almost 50cm times few millimeters times two..
I wonder if it would be worth the effort to scale the parts such as to be able to utilize vapor smoothing? Might reduce the amount of manual labour needed to finish the parts. Apparently PLA does respond to acetone but I've gotten the impression that the temperature is an important factor. Where as if you're able to print with ABS (fume extraction) it's supposedly easier to vapor smooth. Due note that I haven't tried vapor smoothing anything, I'm just curious. Thank you for making this series!
Vapor smoothing does not bring the parts to a specific dimension, it only blends the outer layers so would not reduce the amount of finishing required. It also does not leave particularly even surfaces so I suspect that the friction would be high but you should feel free to give it a try.
The original used springy brass sheet but PLA is very stiff in comparison. You will see the advantage of the change in the next video as the calculator now spins very smoothly but would have been stiff using the thicker spring.
@@JerryWalker001 Yeah, I suppose it's also quite a bit thicker than the metal part, due to the scaling. I can't even imagine assembling some of these at 1:1
I did buy some time ago via ebay a special type 4p4c socket (only seller i found was in the USA). It was tight packaged without any protection in a stiff envelope. it arrived here (Netherlands) in multiple pieces. I did get refund. I ordered later via a well-known parts website (2 in case of ...). It was well packed. I have now a spare "difficult to get type" 4p4c socket.
Great video series, thanks for sharing generously and taking the time to make these videos. I'm fascinated by such devices. I'm new to 3D printing having just got my first 3d printer, but keen to get stuck in with some learning projects. My goal is to design and print my own functional designs, and so this sort of study of mechanical devices is perfect learning material for me - and I'd love to have a working example of a curta model on my desk as reward.
I like your videos and they help me a lot to restore an asr33. I am stuck on the reader which seems to work but does not print any thing except O and ?. Have you an idea please ? Thanks a lot. Stephane.
The info on getting the carry lever right is very helpful. I haven't been happy with the ones I made. I also tried a version someone published with a built in printed spring, and I think it is too lax. One more check you might want to look at before going further is not just that the selectors move the gear, but also that it lines up exactly with the narrow teeth on the step drum. This is easiest seen when in the 9 position. Mine was OK but not perfect, and I adjusted it by changing the dimensions of the bearing and the top.
You are trying to get ahead of my project :) I will demonstrate how I test the alignment in a later video as this is best done when the carriage is fitted. This is because the gears at the top of the drive shafts generate side 'thrust'. However the initial testing I have done is to check that positions 4 and 6 line up in the centre of each gear. I am skipping over a lot of this at the moment because many people seem to have very short attention spans these days and do not like detailed explanations so I try to strike a balance. As with most things I do I have carried out MANY tests and checks as I have proceeded and in a later video I will go into the fact that the current step drum is the third I printed as I modified it slightly to make alignment more reliable.
@@JerryWalker001 Thanks, I look forward to seeing the later videos. I guess I am an outlier, as I like the detailed info. I've learned a lot from it for my own build (progressing very slowly).
Just in case you are still having issues I have found that there are errors in the stl files or manual or both. The last 3 result subtraction gears are in the wrong place on the shaft and so try to turn outside of the unlock part of the bell. They are cause improper addition results. The gear teeth on those 3 gears should align with the top 9 tooth row on the step drum and not the 9 teeth on the reversing part of the drum. Also the counter gear on the first digit shaft is in the wrong place and is not aligning with the required drum teeth in either addition or sub mode. I will show this in the next video.
@@JerryWalker001 Thanks, looking forward to the next video. I'm still working through the turns counter and the earlier transmission shafts. The process of cleaning up the parts is very slow for me, and I'm not happy with the initial prints of the gears. They work but don't work well. Better choice of layer size and support parameters seems to help.
The assembly includes description which starts at 00:00 for those that are interested. If you are not interested and do not want the description then don't watch the video's.
The original design has spring clips where you use O-rings to hold the fixed gears. Marcus's OnShape file includes them but he did not make STLs from them, as they are too flimsy. However, if you modify them to make them thicker, they do work fine.
Yes I know but I decided that O rings would work better here as they are only temporary. In my final version I will just use the plain type drive shaft and circliips. This will allow adjustment of the gear position and they will not need grooves on a plastic rod. I may also add bearing caps at each end of the drive shafts as the cutout in each shaft extends to the end of each shaft and so runs in the bearing holes which causes a lot of friction.
The only other Curta calculator that I've seen was on Adam Savage's Tested channel wherein he had it X-rayed which showed quite a lot or detail. It was rather fascinating and I quite enjoyed it. With that said I'm rather anxious to see how this turns out.
This is looking very good, and I like the finishes you got. I am working on one of these as well; there's a few videos (without commentary, they are just to document milestones) on my channel.
This is a great opportunity to see the workings of the Curta up close! And now in 1080P resolution, too! This looks like quite a project, and I know that we're going to see only the culmination of many of hours of effort already invested.
What a fascinating gadget - interesting to see an old mechanical calculating machine come together from its constituent parts. Glad to have you back! 😊
I was so happy to see the notification of a new video from you. I have had to be contented with watching some of your older videos - the Friden mechanical calculator "unboxing" video comes to mind. Looks like another mechanical calculator project is coming our way - a Curta style one. All of your videos are worth the wait! Regards, David
Thanks for the update Jerry I know how you feel! Finally had chance to pick your Z80 book up, it’s been sitting on my shelf for a few months but work kept getting in the way. Look forward to what’s coming up. Thank you.
Hi Jerry. Hope you are good and just busy thinking up more ways to make us old electronics/computer people have nightmares. I have recently retired from the world of industrial systems repair, encountering many ancient horrors buried in the back of production line factories. Sooo.. I really loved your PDP11/32 series.. (not at all.. there are some still struggling on in this neck of the woods) I just wanted to say I absolutely agree with everything you say in this video. I really enjoyed the "design and build.. maybe" series and have been meaning to buy your book. I tried to build a Z80 computer back in the early 80's but couldn't ever quite manage to source the bits.. mostly ram chips.. Now we come to what I think is the main trust here.. the "entitled generations". Yes.. absolutely. A close friend is half my age.. he desperately wants to be something.. no idea quite what.. First it was electronics.. as he was running little more than a computer board swapping attempt at a business.. but after my attempts to teach him anything of worth he decided that was too hard and then went on to trying to be an engineer/machinist (my pre computer/industrial life after school I was a turner) And now.. well.. Trying to win the Olympic 100m after watching a couple of videos on youtube rather than going out running seems to be the goal.. without even beginning to learn the basics.. This is a guy who can't take a relevant measurement with a multimeter.. or a set of calipers.. The goal seems to throw money at an idea and hope it somehow magically just happens. I try.. I really do. But sometimes I just want to get hold of his whole generation and bash them round the head with one of the textbooks we were expected to know from cover to cover back in the 70's. Last week.. "This is a file.. you use it like this.. there is a lot of feel involved".. Goes at it like somebody trying to cut their way through the Arctic ice sheets.. puts a couple of deep gouges in my soft jaws into the bargain.. "Did you learn nothing at school?".. "We never did it".. They seem incapable of watching and paying attention.... What goes on in their heads when somebody is giving away free skills and knowledge?.. I see the Homer Simpson clockwork monkey bashing away... He's banned from using my drill.. after the 3 seconds he tried to drill a hole with it... And here I am.. and I'm a girl.. and I did some basic metalwork and woodwork back at school.. not a lot.. but enough to make a bracelet out of some copper pipe and a spatula for cooking classes.. My mother was a civil servant.. she built roads.. big roads.. dual carriageways with bridges over rivers and roundabouts and traffic lights.. those kind of roads (Hereford is one if you want to know) my father was one of the Concorde design team.. I guess it comes from there.. What I observe from the 30 somethings and younger.. At school they were taught how to whine and make excuses and expect it all to be done for them rather than anything of value.. They will spend longer making excuses about why they can't learn something than it would take to pay attention and learn it .. I'm surprised they can even dress themselves.. food comes by delivery or takeaway.. capable cooking is beyond them..grrrr.. We didn't build the internet so our kids could be ignorant entitled and stupid.. but here we are.. Learn something every day.. even if it's only "Eating Pringles and sitting at the computer all day will make you fat".. (I love exercise.. I can sit and watch people doing it all day) Rant over.. Humans aren't going to make it.. are they..
Thanks for the message, I have been in touch with many like minded people while making these video's but I also have to deal with a lot of entitled individuals who are not willing to put in the effort and expect everything to be handed to them. I will begin posting more videos in the next week or so but decided to have a break to catch up on some projects. Videoing a repair makes it take 3 to 4 times as long and my videos are not 'staged' as so many RU-vid videos seem to be. One interesting thing I have noticed is that the people who whine about my videos have no content of their own so have no idea of the work involved or that it is up to me what the topic of my videos are. So many people seem to be under the impression that if the video is not exactly what THEY want then I am wrong. I did run my own business for a long time and retired a few years ago but it was very evident over the last 20 years when employing younger staff that society is in trouble due to the over entitled generations that have appeared. Having said that some of my viewers are young AND enthusiastic AND willing to learn so if enough people try to provide information then we may still have a chance and that is why I started this channel. It is just not always appreciated :)
