New colleagues, new burner and progress on gas analysis system | week 8-9/2022 

Thank you, looks like you are solving problems faster than new ones arrive, and are making great progress.

It's good to have you back

Always brightens my day to see you post a new video

Finally got the chance to watch this. Thanks for putting these videos out. I've been following you guys since the early days.

Dont put the scroll pump the same table as the turbo. The vibration will shorten the turbo's life. Bad bearings can cause oscillation in the rotational speed too.

Your analysis system is faulty - but not for the reason you think. I'll outline two points: 1 - By butting the tube up against the glass like that, and sealing the _outside_ with epoxy, you're creating the mother of all virtual leaks, which will significantly impact your RGA readings. If you really want to do this right, you should just seal a short piece of tube to the envelope at the creation stage, without blowing through(i.e. a second "blind" evacuation tube), and then half-drill it. Alternatively, the way this is generally done is outlined in #2. 2 - If you have a long-term sealed, self-contained system, the way to create an analysis port is by adding a second, open tube with a glass-to-metal adapter(i.e CF1.33), connected directly to a UHV-specific valve(see below). You evacuate and fill the system as normal, and then when time comes, you connect it to the RGA and simply open the valve. This also raises another issue - if you just _dump_ all the gas from the tube into the RGA, you'll get completely garbage readings. If you want to do a single-shot analysis from a sealed volume(i.e., get more resolution), you need something to seriously restrict the flow. This is usually done with something called a "variable leak valve", which you can also use as a long-term sealing element when closed. You can find them on eBay for a few hundred euros, just make sure the sapphire/diamond flat is not damaged. Or brand new, for around 600-900. Oh, and for turbo controllers, just switch to open loop operation when you reach a certain margin. When I designed mine, if the speed was within 5Hz, I just locked it to the set speed and a minimum current(adjusted by hand). If it dropped, then I went back in sync.

those Unitorches are a weird beast. I have a love/hate relationship with mine. it definitely frees up a hand when you might otherwise be using crossfires and two hand torches at the same time. I understand the struggle to get a narrow heat band on large diameter tube.

Absolutely fascinating. Always look forward to your updates.

...krásná práce...radost se dívat...

Fantastic work by an amazing team, Bravo!

Ať se Vám daří!

good to see all the good work! Very nice! Greetings to the family.

The progress you all are making is wonderful to see! Thank you for investing time to create such a video, it is positive news.

Thanks for the update, your videos are always so enjoyable.

So good to see you back in a video ! Your progress are fascinating, thanks a lot for sharing so much details. Take care !

It's great to have another video! And good to see that progress is coming along with the various projects. I hope the next video won't be quite as far away, but I understand if you time is needed for more important things. Best of luck to you and the team for the projects you're currently working on!

Thanks for the updates!

Excellent machining work on that chuck... turning that big chunk of steel on such a small lathe shows a machinist with more skills than I could ever hope to have.

Amazing how far you have come since starting videos.

Thank you!

It's so inspiring to see how long you've gone with this endeavour :)

I like the bgm music.

Good to have you back sir! I will soon build one of your clocks!

Scientists and masters at work 👍👍👍👍👍

Great content folks.

Cool things you do! thanks for video!

Luv ur work!

Looks like the glass will need some normalising after the joint to reduce the stress.

Thanks

Wow, soo many new things happening . The RGA setup with a hammer to puncture the tubes is really ingenious!

Amazing well done. Keep up the good work 👍

Such good videos! Keep up please!

Wow, that is a cool custom chuck. I dare no to think how expensive that piece of Teflon must have been... Also great to hear that you are working on the "freezing" bug. I noticed it two times in the last weeks on my clock, but I did not think much of it.

Good to finally see how Radim looks like ☺️

I was reading all the questions about "can you anneal the glass?" and your answers with reasons that doesn't work because the heat will oxidize the internal elements, and I had a "probably a bad idea but it might work" thought: There isn't much physical contact between the envelope (in the areas where you'd want to heat it) and the internal elements, so in principle you should be able to maintain a temperature difference between them. I wonder if you could flow a cooler gas through the inside of the tube to cool the internal elements while heating the envelope. It shouldn't take a lot to keep the grids cool.... Of course, there is probably a simpler solution too. :)

In regards to the stresses in the glass, i wonder what would happen if you'd use a 5th hand on the bottom burner that's pointed such that the flame is fanned out towards the base of the tube, angled up (so it doesn't interfere with your work). That way, even if you do have stress in the glass, it's less pronounced into on spot. Regardless, normalizing seems to be something you'll need to consider, that's a pretty sharp demarcation line on the glass. Source: a few years back we needed to test various concrete formulas against sea water and we ordered specific lab equipment out of glass. A sharp demarcation line caused most of it to crack as the heat cycling tests began. The glass manufacturer said they fixed it by "fanning out the heat pattern". I assume that's what they did in situ (the complicated glass to metal ports kinda blocked any potential normalizing process).

Congratulations, your machinist is an artist. An elegant solution for sealing the top covers on the tube. Ideally there would be no stress point. However it is all on the side and uniform now. That’s a huge milestone. Are you going to live with the stress demarcation point as is or are you going to try and feather it out more? Hopefully it will be fine as is. Let us know how it goes.

I assume time spent in an annealing oven would cause more oxidation - so is not a solution to the build up in stress in the glass?

Nádherné video jako vždycky je neuvěřitelné na kolik problémů a faktorů je potřeba brát ohled ale věřím že výsledek bude za tu námahu stát těším se až to uvidím. Jenom bych dával pozor na tu turbomolekulární vývěvu správně by se neměla pouštět mimo vakuum kvůli tomu aby se nepoškodily ložiska.

This is really HIGH Tech....

Please upload videos more frequently. Thanks.

Really cool that you're able to create complex, high-precision tools like that! Were you a machinist prior to venturing into Nixie tubes, or is this just picked up over time?

I think the purging gas should be injected as far forward as possible an escape to the back. This way the gas is always flushing away the oxygen. How the construction is now, the gas will move to the front as long as there is not enough seal, but at some point the gases from the flame will not be removed from the front, and this is the moment when left over oxygen reacts with the internals.

I saw, the ceramic cups and plates are burned in oven to eliminate stress inside material. Maybe, H-tubes are need to be burnet in oven too?

hi, maybe my question is stupid. What is the lifespan of these tubes? Is it possible that need to refill with gases? If yes it is technically possible or after a certain time the tube will not function anymore?

I wonder if a hydrogen flame might reduce the oxidative process, you could run it quite rich to deoxidise things. Of course then you would have more lovely hydrogen to pump down :-) I wonder, could you anneal during the bake out phase? You're pulling a vacuum then so no oxygen to worry about and you're already in an oven? Just now it needs 500c "easy" lol.

8:40 You most likely noticed it but the rotor turned the wrong way there.

I am curious, do all this equipment would be usable to build amplifier tubes? Some tubes are getting rare or difficult to find and I was wondering if you could build such electronic components

Dobrý den Dalibore, nechat nás půl roku o takovém půstu 🙂 měl sem celkem strach že se Vám v rodině nebo v týmu stalo něco nedobrého a popravdě sem se i bál mejlem zeptat jestli je vše v pořádku. Jak se mi ulevilo když 22 února přišel hromadný email 🙂 Co dodat k videu? jako vždy zase obrovský kus perfektně odvedené práce. Ta teflonová kleština super. Doufám že další video nebude až o prázdninách 🙂

Привет! Когда же вы наконец сделаете лампу наподобии ИН-23 для написания текста.

Is there a price point for a 4 digit clock?

10:07 200V is WAY to high for this pump, it should be around 70V.

Have you tried tempering the glass tubes?