Another Dirty Turbomolecular Pump 

I can only speculate that those copper fingers are in fact some sort of Shaft Grounding Rings, to protect the bearings. Especially if those bearings are ceramic. It's hard to tell from the footage, but it looks like the rotor of the motor is an integral part of the overall pump rotor. Specifically, the squirrel cage of an asynchronous motor, fitted to the end of the rotor shaft. That will induce circulating currents in the rotor that will escape, one way or another.

From my experience, the Turbovac 50 does not need additional cooling, it will happily run at 50c operating temp, above that its a problem. Once the bearings have distributed the grease after sitting for a long time, and with minimal gas load, it shouldn't go above 40c. I also had a smell issue coming from one pump, it was degraded bearing grease, it went away after A LOT of heating and pumping, the smell was like something rotten... Turbovac 50 is a great little pump, it has a very rigid rotor setup, so you can move it while its running, unlike the HiPace80 that will self destruct if you sneeze near it...

I used to work for a company that built these pumps, serviced many. Some where very badly damaged when the bearing failed and all the turbine blades had been stripped off in the subsequent crash. We call those pumps, "Corn Cobs" as the stubs on the core resembled an eaten corn cob. The precision and beauty of these devices was always amazing.

Why am I watching this? I’ve never even heard of one of these before today

The copper ring keeps the bearings from pitting due to static discharge. Latex gloves have natural protein that can contaminate your work. When you spun the bearings by hand they sounded dry. I don't know how much lubrication is needed for bearings in this application. Pumps of this design should run hot on the working side as it helps pull a deeper vacuum. I've seen some pumps use a blanket of foil to ensure they stay warm enough. If you want to cool any part of this pump cool the bearing end.

I think the copper piece is for heat dissipation. The bearing is in vacuum and can overheat if there is no path to cool it. The copper fingers provide a path for the heat to diffuse out of the pump and into the bottom housing.

The copper piece looks like it is designed to accept induced eddy currents. Possibly a shield to protect the electronics from the induced AC from the windings.

1:15 Two things come to mind. They may be independent... or combined. 1: Potential for left hand threads. 2: Chemical thread locker. Heat threaded area to about 250°C

I worked at Solyndra, we used TMPs in Panel Framing Leak Detection of the silicon oil filled solar modules, unfortunately when a leak was detected it meant the TMP on that set of four modules was now contaminated with silicon oil. At first we would partially disable the pumps and rinse with IPA but as more Panel Framing tools came online we were overwhelmed with oily pumps so it got to where I would just cap and fill half way with IPA and shake for a few minutes, dump and repeat then bake out and test. It worked very well and good thing because we would have had to have a great number of pumps on hand if it didn’t. Nicely done video 👍

You use a high amount of Helium for the leak check. You contaminate your workplace with Helium and it can be difficult to do a second Test in a shorter time period. Because Helium is everywhere. Normally you let it come out on a tip of a needle. You can set the amount be holding the needle into IPA and adjust the flow to slow bubbling.

I don't even know what a turbomolecular pump is, I got this recommend to me.

Ive never seen inside a turbomolecular pump before, what fantastic tolerances to ensure the blades dont touch when spinning. This stuff is way outside my experience but fascinating none the less

I have dismantled and cleaned the same pump like two or three years ago and it as much nastier inside and really had a terrible smell to it, the copper fins were extremely corroded and covered in green oxide, I also did not disassembled the rotor because I couldn't get it apart and I didn't want to mess up the balancing.

As somebody who is new to working on TMPs at work, I really appreciate your vids! While like no documentation is available regarding rebuilding specific TMPs, they're close enough that your vids are useful as references.

so these pumps are basically the compressor section of jets engines

You will need to rebalance if you disassemble completely. Thanks for sharing :) very cool

i used to do helium leak tests in a clean room - filled some latex gloves with helium and floated them around room - was amazing how many asked - how I did it

I had a conversation with the tech support guys over at Edwards vacuum pumps and they said that they would only work on pumps where the customer could sign a document to certify as to exactly what chemicals it had been exposed to. Otherwise, they would refuse to service the pumps. I hope you know exactly what this pump was used for. Apparently they are often times used for some pretty nasty stuff.

Old Leybolds used greased bearings and did not last long. They switched to oil-lubricated and had more success (but could no longer be mounter horizontally).

This guy running helium leak checks in his garage like I do at work checking chambers for silicon wafers 😅 nice!

due to high speed, the dry air will carry static charge and give it to the pump, i think the copper sheet is for that

such high quality content. thank you so much!

very good engineering of that thing

Copper is static discharge path to prevent bearing damage

I’ve never seen a turbomolecular pump that tiny before! 😂

I know that grease is very expensive, I work for an NDT company, you only have to apply enough to make a light sheen. You shouldn't see any globs or texture when applying it. If you use too much, it can be sucked into your system(potentially adding to the contamination in your turbo). Also the usual flow rate for helium, especially when doing such a small test fixture, is three bubbles a second. This can be measured in room temperature water. When you place the nozzle under the water, you should see three small bubbles form in one second. Too much helium doesn't hurt, or make it easier to find leaks, but it will screw with your background reading on your MSLD.

7:16 9.5e-06 mbar is more than ok. That’s insane.

The copper piece is probably a leaf spring for bearing preloading. Most electric motors have wave rings for the same purpose.

Those must be the hydrocoptic marzlevanes I've read about. When fitted to the ambifacient lunar waneshaft, side fumbling is effectively prevented as well as producing power from the modial interaction of magneto reluctance and capacitive duractance. Quite remarkable, really.

My thoughts on the mystery copper part within your pump is that it’s likely a spring to ensure the rotor/stator blade assembly stays together somewhat tightly and resists vertical movement along the shaft (lol that’s what she said…) and prevents blade/blade and blade/housing interactions which could be catastrophic… I saw someone else mention it’s some sort of bonding mechanism to prevent any static buildup of the shaft and rotor to protect the bearings, but my understanding of this sort of motor is that the only electrical activity within the rotor is back electromotive force (BEMF) in the armature which dissipates as heat leaving nothing static, but I’m no engineer and am in no way formally educated so what do I know. Hell, perhaps it’s both a spring for turbo blade assembly stability as well as a bonding assembly all in one…🤷🏾‍♂️

The leybold pumps are simple to fix phiffer pumos are nightmarish. This one seems very easy as well. ❤

They gave me no end of problems when working on x ray inspection machines

0:55 Its evident its an -90 pump just by the simple fact that the vanes are just bent to get the right shape instead of being milled from a solid piece as newer are. Its also evident its older due to the fact that the edge of the vanes now after they have been bent have a small sliver of a 90 degree angle pointing at a angle upwards to the chamber so some small amount of gas will be going in to the chamber again instead of being pumped out, so these pumps are little slower than all others and also have a slightly lower ultimate vacuum.

Using a can bus or rs485 to collect data would be a great feature. And I know that this video is pretty old by now.

Perhaps that copper sheet is an electron emitter to neutralize charge in the gas stream.

Oh my lord I haven't seen anyone disassemble or otherwise work on such a neat little machine, only other folks I know who do similar things are The Thought Emporium and NileRed!

Amazing job well done how are you 😊

The screws that appear to be super tight might have a thread sealant to lock them or are reverse thread (lefty tighty)

its funny that you let the prepump running for a while before you start the TMP, at work we got a new highvacuumoven with a spektrometer and it has a Turpovac50 for its own vacuum side and we have like 2 meters of pipe to the prepump that turns on the same time as the TMP. the entire setup for it was planned by Leybold and so far works fine, needs like that 2 min to get to operation vacuum. the oven needs way more time to get under 5.0e-04 mbars that is the limit for the valve to open :D

Electrostatic dust is heavy to remove for turbine and that copper plate probably is special to discharge some residual voltage, but I’m not sure

Thanks, good video, very educational _)) Do you know what could be a possible reason why the HiPace 80 spins at 100% speed but only reaches as low as 0.032 Torr? (excluding leaks)

The copper ring... they work as shims (spacer) perhaps?

That copper piece is to dissipate static charge

That looks like the thing off of Jurassic Park

1:20 dis nuts🤣

That copper shim that you have wondering about, I believe that's for neutralizing static electricity, I'm not sure

Can you make a video describing the pros and cons between a Turbomolecular and diffusion pumps? I need a vacuum pump to make art display plasma discharge tubes but don't know which is the right one. Thanks.

How does something with this many loose parts right next to high frequency spinny things not make air raid siren levels of noise

5:50 yeah if you have a helium leak detector you end up using it for everything. Glad you're getting good use out of it. Turbomolecular pumps have a great compression ratio for oil due to the high molecular weight, so I would leave it running a while (days) but monitor the motor drive power (make sure it's either staying constant or decreasing) as that may be more effective and save you some troubleshooting for dealing with the last bit of oil.

I used to rebuild maglavs for Alcatel before Pfeiffer bought them.

nice job, i number the parts with permanent marker to assamble them correct, the vacuum grease seems a bit execessive or not necessary. Also because its aluminium, i cleaned the parts in like 25% NaOH, but with the oil you had i guess thats enough. Maybe instead of taking it appart again, just let it run for a week? (but e-6, with nothing attached, is a bit high)

I think the copper disk is for static discharge!

Copper piece is a shim to get the correct pressure on the O ring the fins are to disperse heat

The copper fingers look like some kind of Hall effect device.

I'd love to get my hands on a pfeiffer leak detector

Nice to see someone giving some love to these kinds of pumps. When you spin the pump by hand is it slowing down to a halt or is there some „abrubt“ stop at the end? If so the bearings may not be the best anymore. Also did you do a soft start for starting the pump after reassembly? The theory behind this is for the bearing that may have been sitting for some time and being somewhat stuck, meaning the grease in the bearing may increased in viscosity due to not operating the pump. What could lower the life expectancy of the pump/bearing.

The rotor might feel okay but on that type of equipment the fact you can hear it spinning the way it did at 1:34 to me says it indeed was discarded for a bad bearing.

How do you always get those cute pumps :( the smallest i always get are 15kg kinetic bombs.... that piece of copper is really interresting, i have little clue as to what it is, but id expect something usual or boring like heat transfer from the motor coils to the casing, or just to get a better seal to the spacer, or a fine spacer itself to fix the bearing in a more rigid way? yeah if anyone know, i too wanna know it now

If i am ever get my hands onto a Turbomolecular Pump i know what to watch. But i feel like this will never happen.

Can this sheet be an abuse indicator? For example, if a user dumps a lot of gas into a fully spinning turbopump, the turbulence will bend these leaves out of shape. That can later be used by servicemen to see if the pump has catastrophically failed due to manufacturing/design defect, or abuse...

Can you please mix lime juice and lithium?😀💙

alcohol cleaning should always be done last to drive any water out of the cracks and prevent rusting.

Hey, I actually have an osaka 1800L/m turbo pump with controller. It has quite a bit of corrosion on it. would you be willing to point me in the right direction for restoring one of these?

So how are you doing with my Mr. Fusion I dropped off a week ago?

Hi AT, I´ve got a question. Are the rotor also weighted or is it just the shaft? Kind Regards

What tweezers do you use?

I wouldn’t touch the rotor. Why not just heat and vacuum?

sorry I just wondered to this video by accident. What is the purpose of such a pump?

Could the copper be functioning as a heatsync?

hadnt the older Tvac pumps a nasty habit of exploding?

What are these pumps used for

Noice

it surprises me that still a lot of people know these apparatus. very high end very niche ... and if you want to improve the bearings.... rollerscate ceramics do better

Do you love next to a busy road? Can't work out what that noise is in your video.

No audio?

How you get such plausible English

I'm not sure that fully disassembling the rotor is a good idea, as rebalancing it later will be next to impossible (this is the first video I see of yours, so maybe you have the capabilities/skill to do it)

Per hour? Are you sure?

1:20 dez

Never spin dry high speed bearings, EEEEK, ! NO! and when you disassembled it appears you did not assemble exactly the same? now it wont be in balance .