Oxidation solved, brazing under vacuum | week 20-21/2022
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- Опубликовано: 1 окт 2024
- Last week we finally solved the problem with oxidation of the digits, the solution was not very intuitive! Also, the brazing alloy arrived, so we could try brazing under vacuum - this technique will be needed for the vacuum relay project.
Thank you for watching!
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You are a master experimenter and production genius. Very impressive to see you invent processes and tooling suitable for production. This is the immensely difficult and very under appreciated work that separates a prototype from an actual manufacturable product.
I was just thinking the same thing. I’m imagining all these similar R&D efforts with the folks at Eimac, Western Electric, and others a 100 years ago as they worked through material and manufacturing science trials and tribulations. I love watching the scientific method in action. Great work Dalibor and team!
Marc, you and your collaborators do impressive work as well!
That`s what Elon Musk loves to emphasize. By the way, Marc, I`m a huge fan of yours!
Yup, this is the difference between all of these failed Kickstarter projects and actual products. There is a world between making a few prototypes in a garage, and actually manufacturing them in medium/high volumes cost-effectively. In fact, this is a field in itself, DFM (Design For Manufacturing). Often, manufacturing processes need to be taken into account from the ground up, and it is frequent for a product to be completely redesigned between the first working prototypes and mass production, so that it can be manufactured. Fascinating stuff !
Of course you're here..! Lol
The media you're using isn't small, nor sharp enough to cut such burr. You also need a specific shape and size. Prolly ceramic pyramids and ceramic balls (in conjunction...maybe, prolly best to have two stages for the job, deburring and polishing separate). Also, the machine itself might need to be of a different type. There's rotation, vibration, rotation + vibration, and the media itself demands a specific type of operation (which itself can be wet or dry). It's a whole mess, but it's worth it once you've figured out what does what because you can work the solution very fast. I suggest getting in touch with a media manufacturer because they can point you towards the right solution very fast, hassle free.
I've also found that adjustments to the intensity of the cut can extend the Thermal ramp-down of the cut, thereby increasing the abilty for the trailing edge to shrink back during cooling phase...just a thought 😉
Probably the oxygen comes in through the hole since it's cooling down, sucking in the air and the purging gas just fills up the space instead of the air in the colldown phase.
It's probably not even necessary to suppose that was happening though. As another commenter said on the last video, gas diffusion happens very fast, particularly at the temperatures they are heating it to and with the hydrogen nitrogen mix they are using. The average velocity of a hydrogen atom at ROOM temperature is well over 2 Km per second!! As long as they keep some positive pressure on the inside of the tube as it's sealing so there is some flow of gas, however small, the purge gas will sweep any other gasses out of the tube on very short timescales, probably less than a second or two and keep them out. It doesn't even matter that the mean free path for collision of a gas molecule at ambient pressure is only like a hundred nanometers - the diffusion still dominates.
@@Muonium1 Thanks for the very good explanation. I actually meant the vacuum port. Sry my english is not the best.
When i was making my own flash tubes for a dye laser project i brazed tungsten to stainless with standard brazing rod and a mapp/air torch. worked fine with the borax based pink flux on the rod. cleaned part by boiling in water. results were good enough for a flash tube, not sure how well the alloy would have worked in high vacuum. I'd just try that wire you have with some borax and a flame torch.
I'm appreciative.
Once again, the possible and the excellence come only after hard stubborn struggles in the perseverance of intense and careful work.
Respect ! Hats off!
Inductive brazing? What the actually hell. This channel is quickly becoming one of my favorites, right up there with Towndends and BigClive.
Regarding the deburring, have you tried a different material as grit? Also, I think the vibration type deburring machines work faster. Additionally, have you considered electropolishing for the polishing step after electroplating? You could try to turn it on in reverse for a short time after alectroplating, so a bit of copper is removed to form a clean surface.
I knew it's the air getting in during the annealing. Thermal expansion of the gas is quite substantial, so once the tube got a little colder during annealing, it sucked air through the exhaust tube. But it was still hot enough to oxidise the electrodes.
Great video, as always :)
Wow, this looks so amazing and you have such a skillful team!
Why not just use flux and braze conventionally? You can easily clean it off afterwards with pickle. Even when brazing under vacuum you'll have to remove the oxides first, so I don't see the advantage. Maybe I'm missing something?
For me it's looking like you forgot to put Flux on the area you want to solder.
If oxidation continues to be an issue in any areas, you may want to look towards using not inert gas but something actively reducing. Be that something like hydrogen gas or somehow putting a getter inside the tube you can continually heat while you do the sealing process. It might even be an option to wash the tubes with acid or some sort of etchant or even an electrolytic method using the wires connected to each digit to get rid of oxidation after it happens, though I’d only do that if it could be properly cleaned afterwards.
I suspect the issue was oxygen leaking in through the side port, even a little is enough to cause an effect.
It's very interesting to watch you overcome so many problems. Congratulation on solving the oxidation problem. Cheers from Australia
Congrats on the H-Tube!
Since brazing under vacuum didn't work great for the relay, have you considered using forming gas here?
You already have it for the H-Tube, and with a hole in that chamber you made you could flush it all quickly and then have the gas work as a flux.
Bravo...always remember that, in the world of Research & Development, Discovery is categorized in one of 2 ways: 1) Identification of Successful Outcomes and 2) Elimination of those that aren't. 👏 good for you!
Next time just get JLC to send you a stencil. They are cheap and professional quality from them. They offer framed ones and just sheet ones for lower shipping costs. Or just have them assemble the whole thing. They do a good job and JLCC who they get their parts from generally has everything in stock if you are using jelly bean parts.
Oh Dalibor! Disappointment! All the fancy equipment you make and use a hand crank on the lathe position shaft! If you have trouble finding a suitable motor with gearbox let me know and I will send you one!
Might be interesting to see a section + micrograph of those braze joints; looks like, even with a reasonable vacuum, they have to be seriously overheated, I think which means the oxides are dissolving in the metal itself. Which isn't great for strength of the filler, but it's strong enough to begin with, I doubt that's actually a problem, but where it matters is on the bonded faces. Seems like the one fell off the tungsten rod pretty easily when melted? But maybe that's just how it melted off, too.
Using some of that 5% hydrogen mix should be pretty interesting I'd bet.
The problem with most reducing gases is flammability..hydrogen would work but we live in 20% oxygen..forget carbon monoxide. And hydrogen is difficult to vacuum.
@@keithjurena9319 They picked up some 95% N2, 5% H2 in the last update, the purge gas used for sealing; might be as simple as bleeding some of that in with a micro gas flow valve thingy. Vacuum doesn't matter during brazing, but residual H2 would need to be pumped/gettered before sealing, yes.
I do not really understand what is going on in this video because it seems to address several unrelated activities. The initial brazing, why not just use TIG to braze? Just use a long-ish post flow...
Exactly my thought? Induction heating works with argon as well - used in industry. You could also melt the glass with hot argon.
This looks like a lot of money in search of personal meaning. Broken philosophy or why academics can't get things done that your average welder would have figured out in a glance.
@@lrakschmidt2880 I wouldn't be so harsh because towards the end of the vijeo they do show old school equipment etc. There must be a reason, but I'm not sure why.
So cool. How how patient your team is and how you are always trying new things
Insert fine capillary with purge gas as deep into tube as possible and allow to leak out between face joint and exhaust port so a constant small overpressure is maintained and there is never a time when the tube has lower than atmospheric pressure which may occur with no flow and temperature changes.
Your approach to identifying causes of problems and methods of correcting them is fascinating to watch.
Would it not be possible to acid-etch the oxide layer after sealing the front?
haven't these guys heard of purging with inert gas. that would have solved the oxidation problem without needing to muck around making the apparatus
when MIG, TIG welding metals, inert gas atmosphere like Argon is used.
Why not use this technique here ?
sorry just came in on this the 1st time, but have you tried purging the wires in a quarts tube with argon and then aplying the induction coil?
I’m not an expert but maybe flux when soldering or brazing would make this 1 million times easier?
Few likely outdated and unwanted suggestions.
Your tumbler is using media that is way too large, id recommend glass media (glass blasting media) or vapour blasting as that will add a nice shine, deburr and do a pre clean before ultrasonic cleaner.
For the brazing, for a very focused heatsource perhaps try very high power infrared lasers, 2 or more would make it fast and very localised, and infrared passes freely through glass.
Finally for the sealing phase which is causing oxidation, perhaps have a tube slide in deep of the object with noble gas flow (close to the glass welding spot) it will take away internal heat and cover the interior with a nice flow of noble gasses, once its sealed you can slowly pull the injection tube out
What about coating the numbers with some sort of dissolvable coating while the anealing is going on, then dissolving the coating with a suitable solvent and ultrasonics. Once the coating is dissolved, vacuum dry the sealed tube.
if the bulb is purged initially then the flow almost to zero then how would air get in
Hello last scene I see beautiful machine to get different positions vertical to horizontal what is the types or model name
Hope everything is ok. Been a little while.
Tumbling burs off - I've used ceramic media in a shaker for similar size laser cut steel parts
Just a minor point, the term you should use is oxidisation; oxidation refers to a ion losing an electron and has nothing to do with oxygen!
Why am I thinking of Moonraker? :)
Прикольно, что большие газоразрядные индикаторы выполнены в форме кинескопа (сзади горловина узкая). Хотел узнать, какое минимальное напряжение питания (Вольт) и рабочая сила тока (Ампер) требуется для их работы? И используются ли на катодах напыления из щелочных металлов для снижения питающего напряжения и облегчения электрического разряда? Заранее спасибо! Ваш канал СУПЕР!!!👍👍👍
Wouldn't it be easier to do the brazing in an argon atmosphere?
Amazing ❤️ love it's 👉❤️
What make is the tube furnace?
I'm surprised you went with brazing as your first attempt to attach that wire, the very first thing that popped into my mind would be spot-welding it which might be faster and easier if you can get the weld settings right. Could possibly experiment with some of the better configurable battery tab welding tools (even something reasonably affordable like a kWeld) since the sizing makes me think the energy levels would be similar.
When will you make crts?
You could try heating the tungsten for braising inductively? Hook it up to an arc welder and pass high current through the joint
Ever thought about a better toolroom lathe? The Izhmash 1I611P is an excellent one.
If oxygen is causing these problems, couldn't you use other means of melting like Laser ?
Laser welding suffers similar oxidation and is provided with shielding gas or vacuum in the same way. Even capacitor discharge spark welders make use of an inert gas if they have to make reliable brazes or welds.
Do you think, one day we'll be able to buy one of these?
Pri spájkovaní tyčiek (na vákuové relé) by som do tej hrubšej na sústruhu vyvŕtal dieru, tak aby tá tenšia tyčka do nej zapadla. Malo by to omnoho vyššiu mechanickú pevnosť, rovnako by odpadli problémy s vystredením pri spájkovaní.
What if your lathe lays vertically 😄
🍜
Isn't there any type of flux to remove the natural superficial layer of oxide on the parts, for reference, aluminium gets a 25nm thick layer of oxide in microseconds at atmospheric. I personally think that you need a special flux to remove the oxide, also, in theory, the flux avoids oxide forming, thus avoiding the need of vacuum braising. And sorry if I spelled some nonsense, I only do low temperature copper, brass and steel braising. Thanks a lot for sharing your work
Guys, If I understood the things correctly, all this is around nixie clocks only? No other products right? How many of them are you selling annually? It should be a huge amount to keep all people with salaries, wow
About your frustration with not finding that simple solution earlier, in Spain we got an old tale where Christopher Columbus was having dinner with some nobles after his "discovery" of the American continent, one noble was complimenting him for finding a new comercial route through the Atlantic instead of the old complicated route to the Asian continent while another noble intervened claiming anyone could've thought of that, Columbus answer was asking the 2nd noble to please find a way to ballance an egg upright, the noble tried for a while but it always rolled over, when Colon tried it for himself he cracked the bottom of the egg making a flat surface for it to rest on, the noble exclaimed that it was a stupidly simple solution and Colon responded "yes but you couldn't find it yourself".
The moral of the story is that simple in your face solutions are hard to find but they are also elegant, you found a way to solve your problem without adding extra steps to your manufacturing process, it's a good reason to congratulate yourself
Very nice video. I finally found a company that makes the getters that I was looking for, thanks.
If I may ask what was the price for the getter?
Nixie tubes are going out of fashion
Very nice video. I finally found a company that makes the getters that I was looking for, thanks.
Congrats!!!
Why not braze in hydrogen?
Out of curiosity, is it possible that Nixie tubes could be made more vibration/shock resistant for applications on sailboats?
Been watching a long time. You are coming along on this project very well.
Thanks for sharing
Instead of fighting oxidation, have you considered just washing the tube with acid at a later step to remove oixdaiton?
Interresting
Great R&D skills on figuring this out!!! Beautiful work!!!!
Cool
tig spot welding?
Great news! Congratulations
Wtf did I watch?
Wow. He even has a vacuum tube furnace. Amazing!
heh, bet that lathe jack gets a drill attachment pretty quick if it goes up and down often 😜
have you ever considered the density of the gas letting gravity pull the gas in, allowing air to enter?
Since the gas is heavies than air, changing the orientation of your rig may help make it easier too, but imagine that would be a pain lol
14:22 - Good day. Maybe instead of a handle, take a battery wrench?
super robota
I know it sounds stupid but is there a way to thread and screw the 2 metals together instead of brazing? Great machining btw and congrats on the oxidation free tubey!
Not good idea in high vacuum applications.
spot welding maybe but since they already use that in the nixies, its probably not useful here
When you go that small, you go down such a rabbit hole that it almost makes it pointless to not do it like they did it originally.
We try to make a historically correct replica here, also I believe we can use this technique in the future - so I prefer to learn it :-)
Spot welding would simplify it, but the look would be different..
Electropolishing for the tabs should be the best route!
Daliku, ses borec ! drzim palce !
Cool. R&D is a hard job for you. I see.
We all have to learn, you made it!
I like the music! What was it?
Putting on the Ritz
If the issue is air bleeding into the tubes, how farfetched is it to seal the lathe - or even just the immediate environment of the tube - in a container that is filled with argon? I realize that the torch is a source of gasses that would have to be separated from the argon environment, but you'd at least be able to ensure no air intrusion, instead of "some" that might affect your yield.
Keeping slightly positive pressure in the tube is enough. Problem was that they cut the purging gas during annealing, so gas inside the tube contracted and sucked air in. I think that some pressure regulator would solve the issue.
they need an excess of oxygen in the flame too otherwise it'll leave soot in the glass
First! 😁
just damn.
That poses the question: Where on earth did you get ATMEGA328P from these days? ;-)
Exactly - the official order (made in summer 2021) will arrive at the end of 2023... So, I took ATMEGA328PB from eBay, secondhand.. I once made a mistake and ordered PB (not P) version, this is easier to find now than P.. :-)
@@daliborfarny validate the heck out of them just in case. Soooo many fakes and seconds out there.
@@zyeborm these seems to be ok - surplus from another eu company (consumer), but we will check!
It may sound stupid but...
It looks like the purging gas is more dense than air so... Could you do the sealing vertically?
I understand that moving such a complicated and heavy machine to a vertical position is complex... But...
I'm very happy you overcame your problem!!! I love this videos
their normal purging gas is nitrogen. they were using the CO2 vapour to visualise the flow.
Cool, you guys are great.
Looks, of course, a little overcomplicated. For example, why did you need a solder joint that is not resistant to heat? Couldn't be welded?
Also, from what country you are?
Yo, have you ever thought of making a CRT or an Oscilloscope tube? I need large Oscilloscope tubes for some old vector graphic arcade machines