Thank you to all the comments that informed me that the non-insulated transformer was the cause of the electric shock. That was a careless mistake on my part. Thank you for explaining the reason!

you must be the sole reason for the price increase of used turbomolecular pumps in germany

"Countless people still grow up withour access to a lathe or a milling machine" is such a great intro to the sponsor segment.

The output from a autotransformer is not isolated from mains. So the 48VDC supply you build using the variac wasnt isolated from mains either.

The professionally improvised adapters bring me great nostalgia. Everyone does this, I think.

Variacs are autotransformers and thus not galvanically isolated on the secondary side. So the output is still referenced to mains earth and a single point of contact can give you a shock. Since you rectified the voltage, both positive and negative terminals are connected to the reduced mains voltage (alternatingly via the rectifier diodes) and thus have a certain potential against mains earth/your body. One of those two is probably connected to the pump housing (probably the negative one aka "ground").

I never even finished high school, but somehow you manage to make sense to me over and over again. Thanks for not being afraid to simplify things, and thanks for not being afraid to be complicated where it's needed. Always very interesting, always very entertaining.

You were very lucky that you didn't destroy anything because variacs are not isolated .

Ahh, the good old Pfeiffer experience of having the wrong voltage version controller for a pump. If the pump has already been running for a long time and you are going to pump heavy gasses like argon, you might run into material fatigue of the rotor at some point. You might want to think about connecting the pump to some extrusions to absorb torque in case of a crash rather than have the ISO-KF flange suffer the hit. In any case, very nice to see how your project is coming along.

Tip for using threads locker or pipe dope: put it on the male part of the thread! If you put it on the female part the bolt tip will push out the majority, if applied on the male part it will get spread between the threads all the way in. And on pipes you don't push the surplus into the media side! 😉 Bolts still won't fall out though.

I appreciate the tip about PV Turbo viewer software. I was able to find and download it and also make an adapter for the Pfeiffer turbos we have at work. Thanks!! My team now has much better visibility of the turbo parameters during troubleshooting.

The reason for audible vibrations can also come from the fact, that the rotor speed of the pump sometimes hits exactly the resonance frequency of your chamber (or a multiple of it). Espeacially all the aluminium foil likes to vibrate and make sound ;) I have a spectrometer at work with 9 turbopumps attached, and when I turn all of them on or off at the same time, it not only sounds like the deck of an aircraft carrier, but also some really nasty high pitch sounds from resonating components in between :D

Ah, the familiar feeling of listening to a questionable turbo noise with your hand hovering over the STOP button

A variac is not isolated from mains so the case got full mains on it (there exist variacs that are isolated but they are very rare and extremely expensive) so if not fully understand them they can be lethal, you were very lucky there.

Variacs are not isolated transformers IIRC. So it is possible that this pump is designed for an isolated PSU and connects the body to "ground", but you got the live and neutral swapped and the input voltage is present between the body and mains earth!

Searching for swollen capacitors was the bane of my job here for the first year. I found and replaced three with no luck. One starting capacitor on a coolant pump, a power supply capacitor for an Edwards turbo controller, and one on a small pneumatic control block. Lesson learned, I'm an not an electrician. Lessons also learned at my current job; I'm not an optician, wet chemist, or physics modeling expert. What I am is a middling button monkey. 😅

I guess that autotransformer doesn't give you galvanic isolation that's why you got live on case :)

Awesome video, thumbs up 😎 There was no galvanic isolation on your variac and bridge rectifier, and most likely the negative is connected to the chassis of the controller that's connected to the pump, that's why you was get electric shock!

Strange, I wasn't notified to this new upload by YT until today... Great video!

I just learned about these a few months ago when tearing down a leak checker. Pretty neat stuff. Looking forward to when you get a cryo as well.

We've got some in the mass spectrometry lab with that kind of hours, I can't believe something can do 90,000 RPM for over ten solid years but I guess it makes the high price feel more reasonable!

that 88,000 hours on the pump reminded me one time i bought a "new" 500gb hard drive off of amazon like 10 years ago, when i got it i used crystal disk info on it and it had 300 power on cycles and like 80,000 hours on it i still have it in a box

2:25 I thought you started it for a second LOL Very intuitive explanation of mean-free-path. When I started working at our cryolab, they had a 6FT 25KF bellowed tube between the vessels and the TMP's. It was taking them three hours to pump down to the required pressure for tests. Now it's like 30 minutes

A big 👍👍👍 for a informative video where I learned a lot I can use later for water desalination here in West Sahara.

I really hope you do a more in depth video about the different pump and different mechanism. This is very interesting.

The voltage thing was very confusing at first. Spent a good amount of time making sure that the voltage was correct for my pump. Nice to see that the controller can account for the voltage and not damage the pump due to incorrect voltage.

Hi! Good work as usual! You should replace the oil cartridge in the pump with a fresh one ASAP. Since I have many old used pumps with more then 32000h of run time, I usual just soak the cartridges with fresh TL011 oil, works good but its better to replace with new.

Woww really stunning work!🤩

Ill be honest, i just like spinning turbines and thats why i like this channel.

Your ad convinced me, I should get a lathe!

It may not matter at the pressures you’ll be using for sputtering, but mating threads create PITA virtual leaks for high vacuum. A narrow groove milled or ground lengthwise along the shaft of the bolt wherever there’ll be a nut or it will enter or pass through a threaded hole will shorten the escape path for air molecules and drastically shorten the pumping time to reach higher vacuums.

i learned so much from this video! thanks ;)

For a student you always seem to have very nice equipment! I hope your pump works out for you, I also have a split molecular pump and just blocked up the lower vacuum hole with an aluminum plate. It worked just fine, and although I switched to another pump, I never had problems with it. I definitely got some odd noises when it spun up, but I believe this has to do with the transition from being supported by sleeve bearings to the magnetic bearings once it spins fast enough.

Hi, a fellow German is here and would like to get into high vacuum and building my own clean room for experiments into various topics. I would really appreciate it if you would make a video giving an example how one might get started and what amount of money one should expect to spend just to get started, what type of gauges would be useful and so on. I think it would be very interesting to many others too. Thanks for your time reading this

Have fun with the QCM and its temperature drift ;-) And did you think about using scroll pump - they are oil free and provide a much cleaner vacuum. There are the NxDS15i but also Pfeiffer provides them - and they are very silent!!

I think this controller is just a VFD if u get the voltage,amp and frequency right other contorller/vfd will also work on this pump

Sweet! I have a little pfeiffer TMP I bought for like $150 USD. I'll see if I can get it running

Thanks!

I have zero use for an ultra high vacuum setup, but I feel I need one for some reason... 🤔😂

For SOME reason, for a miniscule moment, a minute part of my Being felt insanely compelled to find: or make: an electrical engineering or electronics manual written in Shakespearian meter... 🤔 🤣

nice!

German plugs are unpolarized if i recall correctly, so it would be a tossup whether the output of the variac was referenced to neutral( which should be around earth or live

Please, for your safety, never use variacs like this! One side is drectly connected to mains. You have a 50% chance that your pump ”ground” is at mains voltage. But you already managed to find out. Thanks for your video!

That thing is sure heavy

I'm pretty sure he spends more time playing with his turbopump collection than actually making vacuums

317 billion rotations on those bearings!

For my bachelors I did QCM meter. If you'd have any problems with yours, would like to build custom one or need help in any way feel free to reach out.

What type of mechanical bearings are used inside the turbomolecular pump? After 80,000 hrs of use, I would worry they might have worn out?

Great video. Can you please point to the turboviewer download page?

You got shock because you are still referenced to mains. You do not have galvanic isolation. You are lucki you didn't connected something else to laptop. You also could get shock fromlaptop. Please use isolation transformer....

Variac you used isn't isolated from the grid and your equipment has GND net connected to its body. So you have phase potential on all your equipment. Never use a variac to power any low voltage equipment without an additional isolating transformer. It is quite dangerous not only phisiologically-vise but also from fire-safety view. And, of course, getting shock from your equipment means draining some current through your body but this current may damage random electronics in your equipment because it goes trhough almost random nets like digital interfaces, sensor cables and so on. *I heard that using turbomolecular pump with no pre-vacuuming with usual pump isn't a good idea. I don't know if it's really true or not but I can see some logics in it.

I like cryopumps

You got an electric shock because that Variac is NOT insulated from the mains. Both the controller and your computer is at mains potential. This is VERY dangerous. Please do not do this!

9:50 Going to build a milling machine soon?

What is the discord channel you are on for the vacuum stuff? I have 3 turbomoleculars pumps, want to sell 2 of them

You're not using the massive pump on your chamber anymore?

"Manual? No, it's automatic, why do you ask?"

No, no I have not seen a turbomolecular pump like this. Probably cause the only place I ever see such pumps is on your channel 🤪

You should use Raspberry Pi rather than whole PC for monitoring and even maybe controlling the vacuum table components.

I thought it wasn't safe to turn on these types of pumps in open atmosphere. Was i misinformed?

I have to say, a German riffing on Shakespeare makes me feel grossly ignorant...well played.

60k RPM? 😮

what about antimatter chamber gas annihilation pump? oh sorry this is a spoiler

Meanwhile me first of all what is molecular pump

Electrolytic caps are such a chronic failure point. Why are they still used, surely theres a more reliable alternative!

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Never run a turbo pump at atmospheric pressure, it needs to be in high vacuum