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!
if you want a tip for the baffle, in all the coating machines I have used they are built like window blinds, with the slats covering each other and tilted towards the top of the chamber (orthogonal to the path towards the evaporation or sputtering source). Also, there is always a 90° elbow between the chamber opening and the pump opening
Do you, or someone you know, have a problem with acquiring turbo molecular pumps? Help is available. You and your loved ones don't have to suffer alone. Visit Lab Equipment Anonymous and begin your recovery today.
Yup. For these types of shenanigans it's good to have a 1:1 isolation transformer handy. It's also useful if you want to use an oscilloscope on mains-connected circuits.
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.
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.
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.
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").
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
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
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.
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
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.
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!
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. 😅
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.
@@AdvancedTinkeringbe careful though, this is only valid for through holes! On blind holes the correct way is to put it into the hole as you did it, then the thread locker gets squeezed up along the whole thread as you compress the space below the bolt.
@@artemiypolozhintsev6190 Not true, if you do that you will hydrolock and risk to Crack the part. Thread locker is way to viscous to get pushed through in quantity! If your blind hole hase enough space behind the bolt you can do that to avoid having the excess on the outside, but then you have it inside the hole for the next time you might have to disassemble it. Let me guess, you are American? 😁
15:37 Yea its pretty much impossible to find any information on these pumps. And btw you cant really destroy a turbopump by starting it to early since they normally have a built in a protection system that if it wont go up to a certain rpm within a certain time or that the current draw doesn't go under a certain time (at start up) if will indicate a fault and stop.
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.
I am an UHV pump specialist for Peiffer and have overhauled a few trubos in my life, I get nervous each time I start a turbo I just rebuilt, Its just sometimes I don't trust myself at 90000 RPM
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!
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.
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!
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
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.
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
So to clarify 48v DC corresponds to about 34v AC. Because of unpolarized German plugs the two outputs of the Variac will be either 0 and 34v with respect to ground. Or 230v and 230-34=196v with respect to ground, depending on which way you plug it in. You rolled unlucky and got the second, and thus basically just touched the live, and got a shock
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!!
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!
I tried to run the turbomolecular pump from different VFDs. It was not successful. I tried VFD Delta special model for spindles up to 1500Hz. It also did not work.
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 have 2 Edwards next 240 pumps that only has 2100 working hours on them. This since the bottom bearing failed most likely due to fabrication error since the ball cage fell of a 60k rpm. Could also have been due to low oil but not sure. Nothing else on the pumps was damaged.
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... 🤔 🤣
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.
Thank you for the offer! I haven't been able to test the QCM yet, as components of the quartz holder are likely missing. I would appreciate it if you could send me an email when you have time, and we can discuss some of my questions. The email address is in my TH-cam profile.
@aftaev I have not because I thought I need an additional controller. I recently got a hold of the manual and it looks like I have everything I need to run it, aside from the power connector. I'll see if I can get it to spin soon. I don't have an immediate need for HV/UHV but it will be good to know if it works.
@@tanner3801 I have a turbo pump PFEIFFER TMH 261. This is a 48v supply voltage. I tried connecting it to a VFD Delta MS300 1500HZ. I changed different V/F parameters. But I couldn't start the engine.
@@tanner3801 My pump does not have a Hal sensor. There are many DIY pump controller schematics on the internet. Search the internet for: "An Open-Source Turbomolecular Pump Controller"
@aftaev I'll double check my manual. What I saw that it requires 240V AC (of course I was already going to double check the voltage and pinout before connecting anything). I'll let you know if I can get it started. Won't be immediate but perhaps in coming days or weeks once I finish up other autumn projects.
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....
There is no harm in starting a turbomolecular pump at atmospheric pressure for a few seconds. You shouldn't vent it when it's at full speed or let it run for long times. But it won't hurt the pump to shortly spin up.
There's a good chance whatever software he uses (self-made stuff aside) runs on standard x86 Windows systems. The Raspberry PI has an ARM CPU. So not a great combination. A small-form-factor x86 PC makes much more sense here, e.g. an Intel NUC or similar.
There is no harm in starting a turbomolecular pump at atmospheric pressure for a few seconds. You shouldn't vent it when it's at full speed or let it run for long times. But it won't hurt the pump to shortly spin up.
Yup its OK to test for a few seconds to see if the motor spins.. The worst thing that could happen is if your chamber has a sudden catastrophic leak while spinning at full speed. This is BAD. I've seen them grenade from that before.😮
@@christopherleubner6633 I usually go with Turbo Salad. I have also heard it called Turbo Confetti. There was no food or fun when either of those happened.
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!
if you want a tip for the baffle, in all the coating machines I have used they are built like window blinds, with the slats covering each other and tilted towards the top of the chamber (orthogonal to the path towards the evaporation or sputtering source). Also, there is always a 90° elbow between the chamber opening and the pump opening
"Countless people still grow up withour access to a lathe or a milling machine" is such a great intro to the sponsor segment.
you must be the sole reason for the price increase of used turbomolecular pumps in germany
Sorry :(
Do you, or someone you know, have a problem with acquiring turbo molecular pumps? Help is available. You and your loved ones don't have to suffer alone. Visit Lab Equipment Anonymous and begin your recovery today.
The output from a autotransformer is not isolated from mains. So the 48VDC supply you build using the variac wasnt isolated from mains either.
Yeah that's pretty dangerous. You get full mains voltage on the pump case if you're unlucky. He was lucky not to fry the USB adapter...
Yup. For these types of shenanigans it's good to have a 1:1 isolation transformer handy. It's also useful if you want to use an oscilloscope on mains-connected circuits.
@@jaymzx0I recently fried something because of this... but it was a junk for curiosity thing and isolation transformers aren't exactly free
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.
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.
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.
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").
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
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
Phew that actually makes me less worried. Thank you.
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.
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
Damn you, low conductance...
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.
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!
This one spins at 60k RPM, but it’s still incredibly impressive.
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 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.
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.
Thanks for the advice!
@@AdvancedTinkeringbe careful though, this is only valid for through holes! On blind holes the correct way is to put it into the hole as you did it, then the thread locker gets squeezed up along the whole thread as you compress the space below the bolt.
@@artemiypolozhintsev6190 Not true, if you do that you will hydrolock and risk to Crack the part. Thread locker is way to viscous to get pushed through in quantity!
If your blind hole hase enough space behind the bolt you can do that to avoid having the excess on the outside, but then you have it inside the hole for the next time you might have to disassemble it.
Let me guess, you are American? 😁
15:37 Yea its pretty much impossible to find any information on these pumps. And btw you cant really destroy a turbopump by starting it to early since they normally have a built in a protection system that if it wont go up to a certain rpm within a certain time or that the current draw doesn't go under a certain time (at start up) if will indicate a fault and stop.
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.
Ill be honest, i just like spinning turbines and thats why i like this channel.
Ah, the familiar feeling of listening to a questionable turbo noise with your hand hovering over the STOP button
Like it will change anything if something goes really wrong haha
I am an UHV pump specialist for Peiffer and have overhauled a few trubos in my life, I get nervous each time I start a turbo I just rebuilt, Its just sometimes I don't trust myself at 90000 RPM
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!
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.
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!
I really hope you do a more in depth video about the different pump and different mechanism. This is very interesting.
I made a video about diffusion pumps (and a short one about my cryopump) but I haven’t covered the others yet.
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
Woww really stunning work!🤩
You were very lucky that you didn't destroy anything because variacs are not isolated .
I guess that autotransformer doesn't give you galvanic isolation that's why you got live on case :)
A big 👍👍👍 for a informative video where I learned a lot I can use later for water desalination here in West Sahara.
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.
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
So to clarify 48v DC corresponds to about 34v AC. Because of unpolarized German plugs the two outputs of the Variac will be either 0 and 34v with respect to ground. Or 230v and 230-34=196v with respect to ground, depending on which way you plug it in. You rolled unlucky and got the second, and thus basically just touched the live, and got a shock
i learned so much from this video! thanks ;)
I’m happy to hear that you liked it and learned something new! :)
317 billion rotations on those bearings!
Haha, awesome, I didn't think about that. That's mind blowing!
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!!
Thanks ;)
I would love to have a scroll pump at some point, but I haven’t found one I can afford yet. But I will keep an eye out.
Strange, I wasn't notified to this new upload by YT until today... Great video!
Your ad convinced me, I should get a lathe!
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!
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
I tried to run the turbomolecular pump from different VFDs. It was not successful. I tried VFD Delta special model for spindles up to 1500Hz. It also did not work.
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 have 2 Edwards next 240 pumps that only has 2100 working hours on them. This since the bottom bearing failed most likely due to fabrication error since the ball cage fell of a 60k rpm. Could also have been due to low oil but not sure. Nothing else on the pumps was damaged.
I have zero use for an ultra high vacuum setup, but I feel I need one for some reason... 🤔😂
Better to have it and not need it than to need it and not have it ;)
I'm pretty sure he spends more time playing with his turbopump collection than actually making vacuums
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... 🤔
🤣
We had a similar looking split pump that catastrophically failed in our MS after we exchanged the failed pump controller!
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.
Thank you for the offer!
I haven't been able to test the QCM yet, as components of the quartz holder are likely missing. I would appreciate it if you could send me an email when you have time, and we can discuss some of my questions. The email address is in my TH-cam profile.
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?
Sweet! I have a little pfeiffer TMP I bought for like $150 USD. I'll see if I can get it running
Were you able to launch it pfeiffer TMP?
@aftaev I have not because I thought I need an additional controller. I recently got a hold of the manual and it looks like I have everything I need to run it, aside from the power connector. I'll see if I can get it to spin soon.
I don't have an immediate need for HV/UHV but it will be good to know if it works.
@@tanner3801 I have a turbo pump PFEIFFER TMH 261. This is a 48v supply voltage. I tried connecting it to a VFD Delta MS300 1500HZ. I changed different V/F parameters. But I couldn't start the engine.
@@tanner3801 My pump does not have a Hal sensor. There are many DIY pump controller schematics on the internet.
Search the internet for: "An Open-Source Turbomolecular Pump Controller"
@aftaev I'll double check my manual. What I saw that it requires 240V AC (of course I was already going to double check the voltage and pinout before connecting anything). I'll let you know if I can get it started. Won't be immediate but perhaps in coming days or weeks once I finish up other autumn projects.
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....
very nicje video!
Great video. Can you please point to the turboviewer download page?
Can you send me an email? I don't know if Pfeiffer wants me to share the link on the comments.
I have to say, a German riffing on Shakespeare makes me feel grossly ignorant...well played.
9:50 Going to build a milling machine soon?
Maybe ;)
nice!
That thing is sure heavy
I thought it wasn't safe to turn on these types of pumps in open atmosphere. Was i misinformed?
There is no harm in starting a turbomolecular pump at atmospheric pressure for a few seconds.
You shouldn't vent it when it's at full speed or let it run for long times. But it won't hurt the pump to shortly spin up.
@@AdvancedTinkering cool! Thank you for explaining that to me.
What is the discord channel you are on for the vacuum stuff? I have 3 turbomoleculars pumps, want to sell 2 of them
I have added the links to the video description.
I like cryopumps
They say autism is neurodivergent. What if not-autism is neurodivergent, but they’ve got a better PR department?
So you’re saying me watching a video about turbo molecular pumps makes me normal!!
You're not using the massive pump on your chamber anymore?
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.
There's a good chance whatever software he uses (self-made stuff aside) runs on standard x86 Windows systems. The Raspberry PI has an ARM CPU. So not a great combination.
A small-form-factor x86 PC makes much more sense here, e.g. an Intel NUC or similar.
"Manual? No, it's automatic, why do you ask?"
but don't you have to discharge the capacitors before working on them? it's dangerous
Meanwhile me first of all what is molecular pump
60k RPM? 😮
what about antimatter chamber gas annihilation pump?
oh sorry this is a spoiler
Electrolytic caps are such a chronic failure point. Why are they still used, surely theres a more reliable alternative!
comment
Never run a turbo pump at atmospheric pressure, it needs to be in high vacuum
There is no harm in starting a turbomolecular pump at atmospheric pressure for a few seconds.
You shouldn't vent it when it's at full speed or let it run for long times. But it won't hurt the pump to shortly spin up.
Yup its OK to test for a few seconds to see if the motor spins.. The worst thing that could happen is if your chamber has a sudden catastrophic leak while spinning at full speed. This is BAD. I've seen them grenade from that before.😮
@@christopherleubner6633 I usually go with Turbo Salad. I have also heard it called Turbo Confetti. There was no food or fun when either of those happened.
@@christopherleubner6633 That will wake you up!