A great tip someone gave me years ago, for identifying the source of sounds in a mechanical system: You take a big old screwdriver and use it like a solid stethoscope, except you pin the little fleshy flap, the tragus, over the opening of your ear with the end of the screwdriver. So it's not 'in' your ear but pushing the tragus into your ear-hole. This transmits vibrations into your ear canal and bones without any air-carried noise. What you hear is any vibrations coming from wherever the pointy end of the screwdriver is touching. More weight on the contact gives clearer sound, but risks damaging surfaces obviously. This is really useful for diagnosing car engines, as it filters out so much extraneous noise, but in your case it would immediately tell you whether the noise is coming from the drum or the motor.
Or just use a stethoscope, and place a small roller bearing into the pipe end to act as coupler for tight spaces. The regular one works well to get to the general area.
I'm a Maintenance Engineer for a TV station in LA, California. On Sundays I'm the only one here in the maintenance room. I usually don't smile but to see you making progress on this computer brings me joy
I was at System Source yesterday for their repair workshop, and got the chance to talk with Bob. Great guy and great museum! Glad you’re working with them to get the Bendix running!
The high school I went to in 1970 had one of these (or a *very* similar model) in their Science Lab, which had been donated by an alumnus several years before when his company retired it. We got to play with it some, which I found fascinating. I still remember its most common error, necessitating one of us students to go get the Science teacher to come fix it. The terminal attached to it would just repeatedly type one line: w000zzy w000zzy (repeat forever until shut off with master switch). Glad to see this old beast, haven't seen one since then.
@@thadsmith4909 Thanks for the memory jog, I had forgotten that 0-9u-z was the first format for hex. So that error would be C000FFE in today's parlance. I remember that error because we found it amusing, teenagers that we were. 'Hey, the computer is w00zzy, give it some caffeine and wake it up!!"
Oiling bearings will work for little while, but the oil will weep out sooner than later. From my experience these metal shielded bearings are better off just replaced.. the only way to get some new grease in them is to literally boil them in grease bath :) The rubber shielded ones can be quite easily be relubricated with grease. But those small bearings are like 2dollars a piece so youre better off just replacing them, use the bit more expensive ones like those made in south korea, they have better grease in them from factory and will last atleast 10times longer than the cheaper ones
You've inspired me; I saved a desktop from the trash with an aim to get it functioning again! My computer isn't as fancy as yours, though, but I'm taking baby steps! Another lovely episode! Thanks very much! I'm so happy to see it spinning up again!
@@UsagiElectric Oh, she's not running yet! It's actually missing everything that isn't the motherboard! I'll have to piece it together over time, but I feel like I can, and you gave me the confidence to try! Many thanks!
Just a heads up, you can buy a stethoscope with a long aluminum prod at the end if you will. I use it all the time in the automotive business and you can locate noises extremely easy with it and they're very inexpensive
I often use the big screwdriver as a stethoscope trick, particularly when working on cars. I was actually going to do that here, but the literally, as soon as I stopped recording, the bearings got quiet and never got noisy again. Makes it hard to find the noise when it won't make it!
@@UsagiElectric definitely use that at work too! I'm glad to hear, not hear, the bearings have calmed themselves. I Work just down the road from the museum in Maryland and had no idea it existed until I saw it on your video. Thank you so much. I love watching you and your thought process on fixing the units, Even though I have little to no idea what's going on after the electrical repair.
Oklahoma University had two G-15s. A vent hood was fashioned just above each cabinet. When we powered up the computer we also turned on a hood fan motor to exhaust the hood to the outside. It reduced the cooling requirements considerably since most of the heat went straight outside.
When I caught wind of this episode's subject, I knew I was going to be a fan of it. Glad you aired on the side of caution and replaced that insulation. Nice work!
"Quiet" in 1950's computer terms is basically "you can enter the computer room while the computer is running *with* ear protectors". A friend (now long passed away) once told me that the corporation he worked at in the early 1960's had a computer room where the printer did an emergency stop if you opened the door due to the noise levels...
I worked in a facility that had multiple IBM line printers operating at all times. They basically had their own sound booths built around them, so the only time ear protection was required was if we needed to vacuum out the scraps and dust while the printers were still running. And this was less than 25 years ago. We _also_ had laser printers driven by the very same AS/400 because the outgoing half of the operation had to use industry standard bar codes. Those at least were nice and quiet no matter how busy they got.
07:50 - the long spin-down is a sign of the oil coating the balls and races thinly. The grease is still there, splashed aside and dry. With no fresh grease this is a very temporary fix. Ungreased bearings have the longest spin-down, however they do not last.
remove bearing units , place in warm oven , pop races apart , clean old grease , add new , place in plastic bag in the fridge for a few mins bring back to room temp rotate by hand
@@clonkex Indeed I know of people who will machine their own bearings when originals are not avalible. ( I mostly work with railway locomotives and re-metalling axles/ends copper white metal bearings is common along with the road vehicle engines ( though end roller and taper bearings are normally just swapped out ).
There's an anime related "This episode was mostly just fan service" joke in there somewhere. Great to hear the thing running up and ready for AC though, and good work brining those fans back around.
Good eye! I did indeed drop it and noticed it at the time. It went all the down, past the door and landed on top the preamp unit. I was able to get it back without having to take anything apart thankfully!
@@UsagiElectric I love it when I hear my 10mm hit the driveway or garage floor, rather than (bink, bop --- silence). I have a number of extra sockets for this reason, and I sht you not, I found one in a pile of leaves by a storm drain years ago. I still have that one :D
I have new old stock for the Bendix G15. For the tape reader/punch I have the delicate optical reader components as well as the lamp. And WHERE did you find a G15 emulator??!!
Where on earth did you find some NOS G15 parts?! The emulator was easy to hunt down though, check it out here: www.phkimpel.us/Bendix-G15/webUI/G15.html
Watching David restore a tube computer made the year I was born has to be some of the best content ever. I love this and the centurion and of course the PDP stuff, I spent a lot of time programming pdp-11 machines
Thank you so much! There's a lot more Bendix, Centurion and PDP content to come! I'm actually procrastinating working on the Centurion printer right now, haha.
Pulling a 40c fever. Watching your videos while sick. Absolutely love your content. I would love to live in your workshop lol. Have no idea how you use the computer but it's impressive to see :)
I'm starting to watch you more and more! Just today I saved an Win 95 computer with all the essentials from going into to the trash! Greetings from Germany!
I really wish I lived closer to a computer museum like system source, would love to visit there one day. That reminds me a lot of how I handle bearings. I have oiled and repaired them that way many times.
How to get oil into a bearing: heat the bearing in a 150 degree Fahrenheit oven, take out, drip oil on the race and then as the bearing cools, the oil will be pulled into the bearing. I’ve used this trick to get oil into Telechron clock motor rotors.
thank you for that tip!! the motor in my WPB-era telechron is getting extremely noisy, and I couldn't figure out a way to get it apart to lubricate it that didn't involve destroying the motor.
@@francistheodorecatte As far as I know, everything inside the rotor is metal. It is usually fairly easy to take the motor frame off the clock movement and then pull the rotor out with your fingers. I baked the rotor at 150 degrees Fahrenheit for about 15 minutes to get it warm. I used Caig Labs DeOxIt oil dropped on the 1 RPM gear’s bushing. The oil gets pulled in as the rotor cools. I had a 1950s era Chelsea Elechronometer with a Telechron movement which didn’t turn at all. I used two bake and oil cycles and it has been running like new for a few years. I have tried the trick a handful of times and have not yet found a rotor which could not be reduced with the method.
I've heard of using a soldering gun to heat up the rotors but I guess an oven would work, too. Personally I carefully drilled tiny holes in mine and pushed in oil manually. This worked fine and both clocks are still running quietly. One important consideration with Telechron rotors is that too much oil causes its own issues, I actually needed to drain some excess.
Amazing. I used a Bendix G-15 in 1967-1969 at the University of Colorado, Boulder, Co. The paper tape punch would get too hot so we always had to pull out the tape drawer when we punched a tape. Reader was ok. Even back then getting the vacuum tubes was a problem. The only place we could get them was a surplus store in Denver. I imagine they are impossible to find in 2024.
It's probably harder right now than it was a few years ago, because one of the biggest tube manufacturers is in Russia. Tube- from Slovakia should be as available as ever, but of course there will be more demand for them.
You should see about adding some sort of thermal switch to prevent the drum from spinning up when it is too cold. While you may be perfect about not spinning it up cold, obviously not everyone will be. You know that from experience as the first drum was likely damaged that way. Whatever system that does that should produce noise so that the person who flipped the switch will figure out what is preventing the system from turning on.
@POVwalkswithrovingcyclops A sign will never work. You very much underestimate the ability of people to miss the very obvious. Also, you're assuming the person who tries to turn it on can read.
@@b2gillsAlso thermal inertia. A really cold night then the AC is turned on. The room might be up to temperature but the big lump wrapped up down the bottom there could still be frosty.
I have to admit I jumped on my chair when you announced you were going to punch a hole on the bearings! But I guess it was the only option. And most importantly it worked! It purrs like a kitten now, well done!
In the UK we have The National Museum of Computing in Milton Keynes that even has a rebuild of the Colossus, it's a fair trip from me and I still want to go, but they have an awesome 3D virtual tour on their website.
@@highpath4776 This particular machine was bought by an enthusiast back in the late 1960s. He bought four G15s actually as the engineering firm that was using them to design the highways up in the northeast was retiring them to replace with more modern TTL computers. He held on to all four until he passed in 2021. His estate then got in touch with Bob at System Source museum and through that avenue, one of them ended up here!
I’m guessing that the 5th fan and the big vent panel on the cabinet is to guide air through a filter to prevent dust being drawn in to the machine and especially the drum. Hopefully you can find a HEPA type filter to replace the filter element?
Good catch, the big fan does indeed pull air through a filter, but it doesn't actually use anything fancy as the filter material. It's just a run of the mill house air conditioning filter that you can pick up at any hardware store!
Saludos, como me encantan sus videos, máquinas asombrosas que nunca volverán, con una calidad de piezas y construcción meticulosa, genial ingeniera, hechas para durar cientos de años, era una ingeniería superior a lo de hoy día, dónde, la obsolescencia programada no tenía cabida, ni el recorte de investigación, ni la avaricia desproporcionada de los negocios hoy día, sigue adelante, con tu entusiasmo, tu pasión por la ingeniería de calidad, por encima de modas y avaricia financiera, tus comentarios y apreciaciones son muy valorados, abrazos desde Bogotá Colombia
Great idea with the pick. I was wondering how you were going to oil those bearings in place. 3:30 I really like using heatshrink tubing on my screwdrivers. More durable than tape. If you spray some cheap hairspray on the screwdriver shaft before you slide on the tubing, it'll cause the tubing to stick and not slide off. It's an old AV installer trick. Excess hairspray cleans off easily. One can of Aquanet lasts a lifetime.
Nicely done fan service! The bearing puller is safer than it looks and feels. Finding exactly the right bearings for half-a-century-old fan might be harder but not impossible. However, those kinds of ball bearings usually have great longevity unless you really overexert them. Cleaning the shaft and rotor from dust, gunk and rust is typically more important. Let them run for like ~5-15 minutes after oiling and they should be fine.
Not really, they will have used standard size bearings, and you will find them available from ant big bearing supplier, though you might need to do some cross referencing to match part numbers from old manufacturers, but the most common bearings are all either metric sizes, or US standard inch sizes, very little in the oddball size category. Your new ones probably will have a standard tolerance that, 70 years ago, would have been only available in a close tolerance bearing.
@@SeanBZA Or just get a pair of callipers out and measure the existing bearings. You only need three measurements of bore and outside diameters and thickness and you will quickly be able to match them up. Frankly, bearings are consumable items, and my experience of "reviving" them is that it doesn't last and it's better to replace them.
@@jonathanbuzzard1376 Yes they are consumable, but with the one set being set up with a special set of, now long gone to the recycler, tools. Short of getting a picture of the tools, and some instructions on use, you would be hard pressed to align it again.
@@SeanBZAfor the drum bearings for sure. For the fan bearings, there is no way you would have me doing anything other than replacing them. It is just not worth it trying to revive them when they are a standard sized none critical part.
@@jonathanbuzzard1376 Yes, but as Usagi says, those are easy, just need a puller, and he will change them if needed, but he did want to have them run, at least to see if the fans work, and to get the rest running. Those are easy to change out later on, especially the big one, and the others can be done with little labour. Drum ones will need to have special tools, ands at a minimum read off the old data tracks, if there is data there, and then figure out a way to write the 2 clock tracks back later on if the bearings fail, though this will also need to be done if the other drum is recoated with oxide. That will at least allow getting the right bearings, and put them in, and then align the drum and heads, and then write that clock servo track back on, and use the spare one as master to write the backup track, along probably with this also being used to test each head for the ability to read and write to the drum as well.
I had to admit that you did a good job on the wiring repairs on fan. There are some concerns about applying the oil into bearing which is not a good idea, because it invite dust to build it up and become caked with bearing overtime. On the other hand, the grease are better it keeps dust out of it. I really respected for all of your work to bring it back to life! Thank you.
Amazing achievement. At 3mm/track on the drum , is it really .001”-sensitive on horizontal alignment? No one would dream of getting that finely aligned in a tape recorder dealing in analog.
I had a grumbly ceiling fan in my bathroom - I did what you did, got some oil in it (I think I used chair lube that came with my office chair decades ago) - 1 year later the fan is still quiet.
Well done, unless there is rust or damage inside the bearings they should run essentially forever with this method you used, if it is just the lube that is dry they should run more and more quiet as the hours goes with the fresh oil in them, great to see you replaced the rotten cables to the fan motor too, it was the right decision
I rebuilt a lot of induction motors for one you should be using grease and not oil, oil will not last unless it is constantly applied unless you have a oiling system it should never be run in motors without sleave bearings also you can get the bearings off with no puller just cover the shaft with tape and heat the bearings with a hot air gun then remove the tape clean the glue apply grease not oil to the shaft in front of the bearing hold the part by the bearing you want to pull and tap the shaft on a hard surface it will pop right off heat the new bearing and regrease the shaft for assembly I learned that procedure from a 60-year-old guy who rebuilds Mill spindles I used it on my mill as well as many motors also for motors you want grease without high pressure additives it will last longer you may not be able to find bearings that have that but its always a plus and what you want if your repacking (as long as its a ball or roller bearing) also the drum has a preload nut there should be a torque spec for this preload nut you will probably have to build tool to hook up to the wrench but that can keep your bearing spinning on center if it wears if its to tight it will over heat your bearing
Nice job. Funny, I did the exact same thing with my tumble dryer bearings about 2 weeks ago that were sounding a little rough. Used some 3in1 oil on mine 🙂Those electric fan motors look fairly similar in size too.
what a win! EDIT: those fans have ball bearings, anymore they have oilite bearings and require dissasembly to oil, or rather toss it and buy a new one.
Ok. Usagi! You just leveled up big-time. You are the best electronics TH-camr by far now I find out your a Tool fan! Today is a good day. Lol. Thanks for your work! It is much appreciated!
In the first fan, one of the fan blades is clearly bent as can be seen around 8:01 in the video, I'm wondering if there's a safe way to bend that back in a way that the blade doesn't break and so it rotates evenly with the other blades.
there's a video of one of these working on youtube, it's used to select projector slides when a kid selects an answer from a prompt, as an example of how computers could be used for education.
@@PINKBOY1006 it literally will not let me youtube is total crap for sharing any information like that. will it at least let me say it's an ibm video from the 1960's and it's roughly 26 minutes long?
Ah, those were the days of computing... when you needed specific training on just how to turn the thing on. "Have you tried turning it off and on again?" would certainly be a procedure with something like this! 😸
small request if it's not to much. For the stars of the show the cute animals you always show, could you drop in the animal names if they have one. like the cat at the end of this video. Maybe do it like classic TV pop up Guest Staring Fluffy. I've long wondered what their names are and I'm sure you said them in videos over the years but my memory is like that first drum storage these days unreliable and needs to be serviced
That's a good idea! I'll start slipping a little note in over the video at the end with the name of the fluffy guest! This week was our little boy named Sue!
Good eye! I did indeed drop it and noticed it at the time. It went all the down, past the door and landed on top the preamp unit. I was able to get it back without having to take anything apart thankfully!
Getting there slowly but shurely! What do you have for software for it though? I assume there's no actual "OS" per say. Do you have any code on paper tape to load it up to do something? Or are you planning to do some sort of "Helloorld" in it's native assemble instructions via paper-tape?
Definitely making progress! The closest thing to an OS that this machine has is ALGOL or Intercom. These were both "high level" programming languages that were loaded up via paper tape. Now, "high level" is in quotes because they're actually much closer to a memory monitor like "Wozmon" than they are to something like BASIC. We do have backups of a lot of paper tape programs, we just need to punch them out to new tapes. Once we're up and running we'll be experimenting with all sorts of different things, trying to get the computer to misbehave and see if something still needs work!
Just yesterday, Tech Tangents has a video where he needed to remove some bearings (v=hudO51kU15w)... and at 8:14 he shows off a plumbing tool which is essentially a small bearing puller, available at either your blue or orange big box hardware store.
Great job with the fans! Around 11:06 - You Americans saying 'backside' in US English instead of 'back', 'rear', 'reverse' or 'far side' (of the Moon) sounds so funny to English speakers. The word has a very different meaning over here.
I'm betting you probably have flat spots on the ball bearings in that drum assembly. If it sat for an extended time, with the weight of that drum on it, even small vibrations (say, traffic on the street outside) can wear flat spots. Which even in a properly greased bearing can cause intermittent bearing noise. I understand not wanting to muck around with a working drum, but if you ever do "recondition" or "re-surface" the non-working drum, i'd go to the effort of changing the bearings.
brinelling is the word for it. That's a good call. I'll wager those drum bearings are pre loaded angular contact bearings and they really hate that vibration without rotation thing.
@@zyeborm Yeah, it's actually recommended by motor manufacturers to rotate things like spare motors every couple of months or so to prevent this. When you have large, expensive motors sitting around as spares, you don't want to install one only to have the bearing fail after a month or two of operation. IIRC we did ours every 6 months.
@@jeromethiel4323 I think GM had a really big problem with this with their "vertapack" system in the 60s. They would pack a bunch of cars into railroad cars vertically to ship them and had no weight on the wheels. They had terrible wheel bearing failures after they arrived at their destination. And we are talking hundreds of vehicles per trainload all with failing wheel bearings months after the customers got them. I don't recall how they fixed it.
@@zyeborm Interesting. I hadn't ever heard of that. But it's not surprising if they were low quality bearings (the 60's were not known for good materials science), because trains have a LOT of vibration.
A great tip someone gave me years ago, for identifying the source of sounds in a mechanical system: You take a big old screwdriver and use it like a solid stethoscope, except you pin the little fleshy flap, the tragus, over the opening of your ear with the end of the screwdriver. So it's not 'in' your ear but pushing the tragus into your ear-hole. This transmits vibrations into your ear canal and bones without any air-carried noise. What you hear is any vibrations coming from wherever the pointy end of the screwdriver is touching. More weight on the contact gives clearer sound, but risks damaging surfaces obviously. This is really useful for diagnosing car engines, as it filters out so much extraneous noise, but in your case it would immediately tell you whether the noise is coming from the drum or the motor.
Or just use a stethoscope, and place a small roller bearing into the pipe end to act as coupler for tight spaces. The regular one works well to get to the general area.
A device called a mechanics stethoscope exists. I’d imagine that would provide any help in locating any other bearings that might still make noise.
@tradde11 because a mechanic's stethoscope with rubber tubes & a plastic tube would be a lot less zappy than a screwdriver lol
@@SeanBZA or you could take it to an expert who will strip it all down, repair and check its fully functional!
@tradde11 I’d love to see a mechanic try using the screwdriver method while driving because I’m curious just how well that would work.
I'm a Maintenance Engineer for a TV station in LA, California. On Sundays I'm the only one here in the maintenance room. I usually don't smile but to see you making progress on this computer brings me joy
Glad I could inject some of the insanity I feel messing around with this thing into your workday!
any cool old stuff there??
- Cool computer you got there bro, how fast is the memory?
- About 70mph
Yeah that make sense
I think if you calculate the revolutions per minute and its diameter, you'll determine it's MUCH faster than even 88 miles per hour....
@@loginregionalunrelated but i speak french
Merci beaucoup et _saludos_ en espagnol. Or sumpin.@@WWQQWIW
@@WWQQWIW
Sorry, 130km/h
"That is how exciting it is to flip this big switch" And that, precisely, is what separates engineers from non-engineers.
It's just so exciting when the electrons do what you want them to!
My Sunday afternoon routine: clicking "refresh" until the UE video drops.
I was at System Source yesterday for their repair workshop, and got the chance to talk with Bob. Great guy and great museum! Glad you’re working with them to get the Bendix running!
Bob is awesome, and a true enthusiast like us!
The high school I went to in 1970 had one of these (or a *very* similar model) in their Science Lab, which had been donated by an alumnus several years before when his company retired it. We got to play with it some, which I found fascinating. I still remember its most common error, necessitating one of us students to go get the Science teacher to come fix it. The terminal attached to it would just repeatedly type one line:
w000zzy
w000zzy
(repeat forever until shut off with master switch).
Glad to see this old beast, haven't seen one since then.
And that is a numerical code using hexadecimal 0-9, u-z!
@@thadsmith4909 Thanks for the memory jog, I had forgotten that 0-9u-z was the first format for hex. So that error would be C000FFE in today's parlance. I remember that error because we found it amusing, teenagers that we were. 'Hey, the computer is w00zzy, give it some caffeine and wake it up!!"
@@sidewinder666666 You were right, it was requesting coffee. XD
Oiling bearings will work for little while, but the oil will weep out sooner than later.
From my experience these metal shielded bearings are better off just replaced.. the only way to get some new grease in them is to literally boil them in grease bath :)
The rubber shielded ones can be quite easily be relubricated with grease.
But those small bearings are like 2dollars a piece so youre better off just replacing them, use the bit more expensive ones like those made in south korea, they have better grease in them from factory and will last atleast 10times longer than the cheaper ones
You've inspired me; I saved a desktop from the trash with an aim to get it functioning again!
My computer isn't as fancy as yours, though, but I'm taking baby steps!
Another lovely episode! Thanks very much! I'm so happy to see it spinning up again!
Awesome! Another machine up and running, that's what I love to hear!
Thanks for coming along with us on these episodes!
@@UsagiElectric Oh, she's not running yet! It's actually missing everything that isn't the motherboard!
I'll have to piece it together over time, but I feel like I can, and you gave me the confidence to try! Many thanks!
Just a heads up, you can buy a stethoscope with a long aluminum prod at the end if you will. I use it all the time in the automotive business and you can locate noises extremely easy with it and they're very inexpensive
I often use the big screwdriver as a stethoscope trick, particularly when working on cars. I was actually going to do that here, but the literally, as soon as I stopped recording, the bearings got quiet and never got noisy again. Makes it hard to find the noise when it won't make it!
@@UsagiElectric definitely use that at work too! I'm glad to hear, not hear, the bearings have calmed themselves. I Work just down the road from the museum in Maryland and had no idea it existed until I saw it on your video. Thank you so much. I love watching you and your thought process on fixing the units, Even though I have little to no idea what's going on after the electrical repair.
4:08 small washer falls into the machine...
I hope that doesn't cause an issue later?
Looks like he caught it in his hand.
@@Ragnar8504No it fell of the screw on the top side and slid off around the edge as he was pulling his hand away on the underside.
@@1kreature And then it was visible on top of the case a few seconds later. He caught it, whether in that moment or after.
Oklahoma University had two G-15s. A vent hood was fashioned just above each cabinet. When we powered up the computer we also turned on a hood fan motor to exhaust the hood to the outside. It reduced the cooling requirements considerably since most of the heat went straight outside.
Your enthusiasm is contagious. Keep up the great work!!
Thank you so much!
I just get so excited when the electrons do what I want, haha.
@UsagiElectric yeah man. Me too. I restore vintage synthesizers so... I totally get it.
When I caught wind of this episode's subject, I knew I was going to be a fan of it. Glad you aired on the side of caution and replaced that insulation. Nice work!
I just love making videos for and about my fans!
"Quiet" in 1950's computer terms is basically "you can enter the computer room while the computer is running *with* ear protectors". A friend (now long passed away) once told me that the corporation he worked at in the early 1960's had a computer room where the printer did an emergency stop if you opened the door due to the noise levels...
I worked in a facility that had multiple IBM line printers operating at all times. They basically had their own sound booths built around them, so the only time ear protection was required was if we needed to vacuum out the scraps and dust while the printers were still running. And this was less than 25 years ago. We _also_ had laser printers driven by the very same AS/400 because the outgoing half of the operation had to use industry standard bar codes. Those at least were nice and quiet no matter how busy they got.
My dad (born in the 1920s) did not want me to get into IT because he was afraid I'd be deaf by age 40.
07:50 - the long spin-down is a sign of the oil coating the balls and races thinly. The grease is still there, splashed aside and dry. With no fresh grease this is a very temporary fix. Ungreased bearings have the longest spin-down, however they do not last.
remove bearing units , place in warm oven , pop races apart , clean old grease , add new , place in plastic bag in the fridge for a few mins bring back to room temp rotate by hand
@@highpath4776 If you are going through the trouble of removing the bearings, it would be better to just replace them with new ones.
@@rocketman221projects sometimes one wishes to maintain "orginality" ones projects
@@highpath4776 Bearings are a wear item. They should be replaced even when trying to keep things original
@@clonkex Indeed I know of people who will machine their own bearings when originals are not avalible. ( I mostly work with railway locomotives and re-metalling axles/ends copper white metal bearings is common along with the road vehicle engines ( though end roller and taper bearings are normally just swapped out ).
That's so exciting to see you're moving on, step by step, to revive this magnificent machine! Thank you for great episode!
Thank you so much for coming along on the journey!
There's an anime related "This episode was mostly just fan service" joke in there somewhere.
Great to hear the thing running up and ready for AC though, and good work brining those fans back around.
I am but a child next to this machine, thanks for taking us on your journey with it!
Your excitement is infectious and I look forward to seeing more.
Usagi Electric just got five more fans for his channel. :-)
4:15 - a washer went between the panels.
😰
Good eye!
I did indeed drop it and noticed it at the time. It went all the down, past the door and landed on top the preamp unit. I was able to get it back without having to take anything apart thankfully!
@@UsagiElectric I love it when I hear my 10mm hit the driveway or garage floor, rather than (bink, bop --- silence). I have a number of extra sockets for this reason, and I sht you not, I found one in a pile of leaves by a storm drain years ago. I still have that one :D
I have new old stock for the Bendix G15. For the tape reader/punch I have the delicate optical reader components as well as the lamp. And WHERE did you find a G15 emulator??!!
Where on earth did you find some NOS G15 parts?!
The emulator was easy to hunt down though, check it out here: www.phkimpel.us/Bendix-G15/webUI/G15.html
Watching David restore a tube computer made the year I was born has to be some of the best content ever. I love this and the centurion and of course the PDP stuff, I spent a lot of time programming pdp-11 machines
Thank you so much!
There's a lot more Bendix, Centurion and PDP content to come! I'm actually procrastinating working on the Centurion printer right now, haha.
7:00 FANtastic
All those selenium rectifiers on the tape reader! Good luck! Great video!
Spoiler: he disconnects them and hides silicon diodes in between them.
Pulling a 40c fever. Watching your videos while sick. Absolutely love your content. I would love to live in your workshop lol. Have no idea how you use the computer but it's impressive to see :)
I'm starting to watch you more and more! Just today I saved an Win 95 computer with all the essentials from going into to the trash! Greetings from Germany!
I really wish I lived closer to a computer museum like system source, would love to visit there one day. That reminds me a lot of how I handle bearings. I have oiled and repaired them that way many times.
Our office furnace fan is out of whack, and the wobble gets me through the day...
'DC up and running code this year'. And somehow someone in 1958 said this and succeeded. Welcome to the future!
Beautiful meticulous work. Your fearless enthusiasm for such a daunting task is an inspiration. Big cheers!
How to get oil into a bearing: heat the bearing in a 150 degree Fahrenheit oven, take out, drip oil on the race and then as the bearing cools, the oil will be pulled into the bearing. I’ve used this trick to get oil into Telechron clock motor rotors.
thank you for that tip!! the motor in my WPB-era telechron is getting extremely noisy, and I couldn't figure out a way to get it apart to lubricate it that didn't involve destroying the motor.
@@francistheodorecatte As far as I know, everything inside the rotor is metal. It is usually fairly easy to take the motor frame off the clock movement and then pull the rotor out with your fingers. I baked the rotor at 150 degrees Fahrenheit for about 15 minutes to get it warm. I used Caig Labs DeOxIt oil dropped on the 1 RPM gear’s bushing. The oil gets pulled in as the rotor cools. I had a 1950s era Chelsea Elechronometer with a Telechron movement which didn’t turn at all. I used two bake and oil cycles and it has been running like new for a few years. I have tried the trick a handful of times and have not yet found a rotor which could not be reduced with the method.
@@wtmayhew might be an idea to mention 150f in your first comment. I just presumed it was C I wouldn't have thought 65 degrees would have done much.
@@zyeborm I edited the comment to state temperature scale.
I've heard of using a soldering gun to heat up the rotors but I guess an oven would work, too. Personally I carefully drilled tiny holes in mine and pushed in oil manually. This worked fine and both clocks are still running quietly. One important consideration with Telechron rotors is that too much oil causes its own issues, I actually needed to drain some excess.
Amazing. I used a Bendix G-15 in 1967-1969 at the University of Colorado, Boulder, Co. The paper tape punch would get too hot so we always had to pull out the tape drawer when we punched a tape. Reader was ok. Even back then getting the vacuum tubes was a problem. The only place we could get them was a surplus store in Denver. I imagine they are impossible to find in 2024.
I’m sure you could whip up a mosfet tube emulator that fits in those bakalite sockets. 😁
It's probably harder right now than it was a few years ago, because one of the biggest tube manufacturers is in Russia. Tube- from Slovakia should be as available as ever, but of course there will be more demand for them.
You should see about adding some sort of thermal switch to prevent the drum from spinning up when it is too cold. While you may be perfect about not spinning it up cold, obviously not everyone will be. You know that from experience as the first drum was likely damaged that way. Whatever system that does that should produce noise so that the person who flipped the switch will figure out what is preventing the system from turning on.
I suggest the noise be a shivery Brrrrrr.
Pair of thermostat switches and a relay i to handle the power. That's a good call.
A pair so you can set low and high temp limits.
All that or a five cent plaque that says "Do not start below X degrees ambient"
@POVwalkswithrovingcyclops A sign will never work. You very much underestimate the ability of people to miss the very obvious.
Also, you're assuming the person who tries to turn it on can read.
@@b2gillsAlso thermal inertia. A really cold night then the AC is turned on. The room might be up to temperature but the big lump wrapped up down the bottom there could still be frosty.
that purr of those fans make me so happy . congrats on getting fan spin,
I have to admit I jumped on my chair when you announced you were going to punch a hole on the bearings! But I guess it was the only option. And most importantly it worked! It purrs like a kitten now, well done!
“Sounds FANtastic” without a flinch 😂 🎉
These old AC motors remind me of the motors in my 1950s model trains! I recently had to take one apart to replace the brushes and oil it.
Your restoration work is amazing.
Thank you so much!
@TechTangents just used a faucet/compression fit puller to pull and press some bearings on a word processor.
Yeah. I like electronics that need manly tools.
Are you even computing if you don't need a flat head screwdriver and stem puller?
Whooo!!!! This is so exciting! Seeing a commercial vacuum tube computer come alive is amazing for someone who grew up in the C64 era!
What a project! Lots of work to make step-wise progress.
In the UK we have The National Museum of Computing in Milton Keynes that even has a rebuild of the Colossus, it's a fair trip from me and I still want to go, but they have an awesome 3D virtual tour on their website.
"a full tool song" is a good time measurement. I use it a lot
Greatest unit of measurement I've come across so far!
Fan-tastic work
Another step along the way! Thanks for the video.
It's nice to see 65+ year old hardware spinning up like new!
wonder how it came to be retained rather than dismantled
It's so cool to watch it amble back into life!
@@highpath4776 This particular machine was bought by an enthusiast back in the late 1960s. He bought four G15s actually as the engineering firm that was using them to design the highways up in the northeast was retiring them to replace with more modern TTL computers. He held on to all four until he passed in 2021. His estate then got in touch with Bob at System Source museum and through that avenue, one of them ended up here!
Fan-Tastik Work!
I’m guessing that the 5th fan and the big vent panel on the cabinet is to guide air through a filter to prevent dust being drawn in to the machine and especially the drum. Hopefully you can find a HEPA type filter to replace the filter element?
Good catch, the big fan does indeed pull air through a filter, but it doesn't actually use anything fancy as the filter material. It's just a run of the mill house air conditioning filter that you can pick up at any hardware store!
Saludos, como me encantan sus videos, máquinas asombrosas que nunca volverán, con una calidad de piezas y construcción meticulosa, genial ingeniera, hechas para durar cientos de años, era una ingeniería superior a lo de hoy día, dónde, la obsolescencia programada no tenía cabida, ni el recorte de investigación, ni la avaricia desproporcionada de los negocios hoy día, sigue adelante, con tu entusiasmo, tu pasión por la ingeniería de calidad, por encima de modas y avaricia financiera, tus comentarios y apreciaciones son muy valorados, abrazos desde Bogotá Colombia
Mr McKimmie would have agreed.
Congrats for well done dedicated work. Please keep going.
Thank you!
Lots more to come for sure!
Amazing engineering. Built to repair.
Great idea with the pick. I was wondering how you were going to oil those bearings in place.
3:30 I really like using heatshrink tubing on my screwdrivers. More durable than tape.
If you spray some cheap hairspray on the screwdriver shaft before you slide on the tubing, it'll cause the tubing to stick and not slide off.
It's an old AV installer trick. Excess hairspray cleans off easily. One can of Aquanet lasts a lifetime.
What a FANtastic episode! [sorry - couldn’t resist]
The start reminds me of videos on repairing old Hornby and Bachmann trains.
I like your enthusiasm and success in restoring these old computers
Nicely done fan service! The bearing puller is safer than it looks and feels.
Finding exactly the right bearings for half-a-century-old fan might be harder but not impossible.
However, those kinds of ball bearings usually have great longevity unless you really overexert them.
Cleaning the shaft and rotor from dust, gunk and rust is typically more important.
Let them run for like ~5-15 minutes after oiling and they should be fine.
Not really, they will have used standard size bearings, and you will find them available from ant big bearing supplier, though you might need to do some cross referencing to match part numbers from old manufacturers, but the most common bearings are all either metric sizes, or US standard inch sizes, very little in the oddball size category. Your new ones probably will have a standard tolerance that, 70 years ago, would have been only available in a close tolerance bearing.
@@SeanBZA Or just get a pair of callipers out and measure the existing bearings. You only need three measurements of bore and outside diameters and thickness and you will quickly be able to match them up. Frankly, bearings are consumable items, and my experience of "reviving" them is that it doesn't last and it's better to replace them.
@@jonathanbuzzard1376 Yes they are consumable, but with the one set being set up with a special set of, now long gone to the recycler, tools. Short of getting a picture of the tools, and some instructions on use, you would be hard pressed to align it again.
@@SeanBZAfor the drum bearings for sure. For the fan bearings, there is no way you would have me doing anything other than replacing them. It is just not worth it trying to revive them when they are a standard sized none critical part.
@@jonathanbuzzard1376 Yes, but as Usagi says, those are easy, just need a puller, and he will change them if needed, but he did want to have them run, at least to see if the fans work, and to get the rest running. Those are easy to change out later on, especially the big one, and the others can be done with little labour. Drum ones will need to have special tools, ands at a minimum read off the old data tracks, if there is data there, and then figure out a way to write the 2 clock tracks back later on if the bearings fail, though this will also need to be done if the other drum is recoated with oxide. That will at least allow getting the right bearings, and put them in, and then align the drum and heads, and then write that clock servo track back on, and use the spare one as master to write the backup track, along probably with this also being used to test each head for the ability to read and write to the drum as well.
I had to admit that you did a good job on the wiring repairs on fan. There are some concerns about applying the oil into bearing which is not a good idea, because it invite dust to build it up and become caked with bearing overtime. On the other hand, the grease are better it keeps dust out of it. I really respected for all of your work to bring it back to life! Thank you.
Well done!
“Blue monolith” (chapter title) made me picture this in 2001 A Space Odyssey. Inscrutable alien object!
I love your excitement and enthusiasm, it's contagious
Amazing achievement. At 3mm/track on the drum , is it really .001”-sensitive on horizontal alignment? No one would dream of getting that finely aligned in a tape recorder dealing in analog.
I had a grumbly ceiling fan in my bathroom - I did what you did, got some oil in it (I think I used chair lube that came with my office chair decades ago) - 1 year later the fan is still quiet.
Well done, unless there is rust or damage inside the bearings they should run essentially forever with this method you used, if it is just the lube that is dry they should run more and more quiet as the hours goes with the fresh oil in them, great to see you replaced the rotten cables to the fan motor too, it was the right decision
I rebuilt a lot of induction motors for one you should be using grease and not oil, oil will not last unless it is constantly applied unless you have a oiling system it should never be run in motors without sleave bearings also you can get the bearings off with no puller just cover the shaft with tape and heat the bearings with a hot air gun then remove the tape clean the glue apply grease not oil to the shaft in front of the bearing hold the part by the bearing you want to pull and tap the shaft on a hard surface it will pop right off heat the new bearing and regrease the shaft for assembly I learned that procedure from a 60-year-old guy who rebuilds Mill spindles I used it on my mill as well as many motors also for motors you want grease without high pressure additives it will last longer you may not be able to find bearings that have that but its always a plus and what you want if your repacking (as long as its a ball or roller bearing) also the drum has a preload nut there should be a torque spec for this preload nut you will probably have to build tool to hook up to the wrench but that can keep your bearing spinning on center if it wears if its to tight it will over heat your bearing
Really wanna see it blinking and ticking and producing some kind of information! You're doing incredible stuff! 😎
So many FANtastic moments in this video!
Love this old beast, absolutely glorious space heater.
Nice job. Funny, I did the exact same thing with my tumble dryer bearings about 2 weeks ago that were sounding a little rough. Used some 3in1 oil on mine 🙂Those electric fan motors look fairly similar in size too.
Ball bearings in a fan? They really spared no expense!
Nothing quite like the hum of a vintage computer idling away, patiently waiting for some instructions from its master.
Like most orange cats, he has Herb Alpert and the Tijuana Brass's "Spanish Flea" on repeat in his noggin.
Someone once told me that orange cats have a single brain cell, and they all share it, which is pretty accurate for our big dumb teddy bear of cat!
The very definition of "no thoughts, head empty."
what a win! EDIT: those fans have ball bearings, anymore they have oilite bearings and require dissasembly to oil, or rather toss it and buy a new one.
Your enthusiasm is infectious. Love your stuff. Cannot wait for that thing to run code. Then we will see if it can run doom 😜
World's coolest 😎 space heater (for now). Cant wait to see it crunching numbers again.
Ok. Usagi! You just leveled up big-time. You are the best electronics TH-camr by far now I find out your a Tool fan! Today is a good day. Lol. Thanks for your work! It is much appreciated!
In the first fan, one of the fan blades is clearly bent as can be seen around 8:01 in the video, I'm wondering if there's a safe way to bend that back in a way that the blade doesn't break and so it rotates evenly with the other blades.
Curious to see how you handle the selenium rectifiers in the paper tape feed. Looking forward to the next video!
Great sound of the machine! I'm realy exited how it looks like.
The nut and bolt power connection for your fan test is a solution after my own heart.
Bless you!!! And I hope you will fix the computer done as soon as possible!❤
there's a video of one of these working on youtube, it's used to select projector slides when a kid selects an answer from a prompt, as an example of how computers could be used for education.
Whoah, what? Can you provide the title or a link?
@@PINKBOY1006 th-cam.com/video/qMU5je6vbf4/w-d-xo.htmlsi=a4tzi6si8H80A5Dp about 22 minutes in or so.
@@PINKBOY1006 IBM COMPUTERS 53034 about 22 minutes in.
@@PINKBOY1006 it won't let me, but if you type in "1960s" "MAINFRAME" "IBM" "DATA PROCESSING" it's in that video about twenty-two minutes in.
@@PINKBOY1006 it literally will not let me youtube is total crap for sharing any information like that. will it at least let me say it's an ibm video from the 1960's and it's roughly 26 minutes long?
Getting closer!! 😄
Ah, those were the days of computing... when you needed specific training on just how to turn the thing on. "Have you tried turning it off and on again?" would certainly be a procedure with something like this! 😸
small request if it's not to much. For the stars of the show the cute animals you always show, could you drop in the animal names if they have one. like the cat at the end of this video. Maybe do it like classic TV pop up Guest Staring Fluffy. I've long wondered what their names are and I'm sure you said them in videos over the years but my memory is like that first drum storage these days unreliable and needs to be serviced
That's a good idea! I'll start slipping a little note in over the video at the end with the name of the fluffy guest!
This week was our little boy named Sue!
Built to last.
Injecting the oil into the bearing was a very nice trick. Sealing it up after made it perfect.
16:27 can relate. Subscribed.
I swear you dropped a washer in when removing the fan at 4:07, just in case you missed it.
Good catch, I did indeed. It fell all the way down and ended up landing on top of the preamp chassis. I was able to retrieve it with no problems!
4:05, looks like you dropped the flat washer inside the cabinet.
I hope it isn't somewhere it'll cause trouble.
Good eye!
I did indeed drop it and noticed it at the time. It went all the down, past the door and landed on top the preamp unit. I was able to get it back without having to take anything apart thankfully!
Getting there slowly but shurely!
What do you have for software for it though? I assume there's no actual "OS" per say. Do you have any code on paper tape to load it up to do something? Or are you planning to do some sort of "Helloorld" in it's native assemble instructions via paper-tape?
"Per se", "its", "paper tape".
@@b43xoit holy fuck, can you be any more of an English Nazi? Who cares???? Get a life
Definitely making progress!
The closest thing to an OS that this machine has is ALGOL or Intercom. These were both "high level" programming languages that were loaded up via paper tape. Now, "high level" is in quotes because they're actually much closer to a memory monitor like "Wozmon" than they are to something like BASIC. We do have backups of a lot of paper tape programs, we just need to punch them out to new tapes. Once we're up and running we'll be experimenting with all sorts of different things, trying to get the computer to misbehave and see if something still needs work!
Very cool. I’m aware of ALGOL but never seen it so that will be interesting!
Algol is higher level than Fortran IV, as Algol introduced direct expression of structured programming.
So looking at those fan assemblies on top. If you ever cannot resurrect one of these motors, you can use a bathroom vent fan as a replacement unit.
Just yesterday, Tech Tangents has a video where he needed to remove some bearings (v=hudO51kU15w)... and at 8:14 he shows off a plumbing tool which is essentially a small bearing puller, available at either your blue or orange big box hardware store.
It’s WHISPER QUIET!!
This thing would be great for Canadian winters, I wonder if it would count as a primary heat source? Do math and heat the house lol
Great video. Great to see the old tech spinning up!
On another note, do you have any problems with your GoPro's overheating?
Great job with the fans!
Around 11:06 - You Americans saying 'backside' in US English instead of 'back', 'rear', 'reverse' or 'far side' (of the Moon) sounds so funny to English speakers. The word has a very different meaning over here.
Very nice progress!
I'm betting you probably have flat spots on the ball bearings in that drum assembly. If it sat for an extended time, with the weight of that drum on it, even small vibrations (say, traffic on the street outside) can wear flat spots. Which even in a properly greased bearing can cause intermittent bearing noise. I understand not wanting to muck around with a working drum, but if you ever do "recondition" or "re-surface" the non-working drum, i'd go to the effort of changing the bearings.
brinelling is the word for it. That's a good call. I'll wager those drum bearings are pre loaded angular contact bearings and they really hate that vibration without rotation thing.
@@zyeborm Yeah, it's actually recommended by motor manufacturers to rotate things like spare motors every couple of months or so to prevent this. When you have large, expensive motors sitting around as spares, you don't want to install one only to have the bearing fail after a month or two of operation. IIRC we did ours every 6 months.
@@jeromethiel4323 I think GM had a really big problem with this with their "vertapack" system in the 60s. They would pack a bunch of cars into railroad cars vertically to ship them and had no weight on the wheels. They had terrible wheel bearing failures after they arrived at their destination. And we are talking hundreds of vehicles per trainload all with failing wheel bearings months after the customers got them.
I don't recall how they fixed it.
@@zyeborm Interesting. I hadn't ever heard of that. But it's not surprising if they were low quality bearings (the 60's were not known for good materials science), because trains have a LOT of vibration.
Amazing work!
eso es un 555? jajajaja es maravillosa maquina.... jamas habia visto algo tan hermoso! gracias!