Fusor Forums

Again I want to thank all who have shared their specific knowledge related to turbo pump intricacies. I have read a bit, I have listened to others a lot through past posts and received information on my specific case. I now consider myself well informed on turbo pumps, but until I have the laying upon of the hands, I will not be more than just informed or well read. The real useful learning adventure lay ahead. I realize this is not rocket science, but it is a process. A process that makes complete the reading, the wise advice and mentoring which with the active use and operation turns it into true ownership of knowledge.

This is what all these forums and FAQs are about...Open source sharing, teaching and learning. Still they mean little until put into practice. As I progress in the installation and application of my turbo, I will keep this thread informed.

Once again I quote from Frances Bacon's famous essays; the one called "of Studies". Remember, these are written in the style of English prose in use in the 14th century. Until you get used to Bacon's complex prose the going can be tough in many of his essays.

"To spend too much time in studies is sloth; to use them too much for ornament is affectation; to make judgement wholly by there rules is the humor of the scholar. They perfect nature and are perfected by experience. Crafty men contemn studies, simple men admire them, wise men use them; for they teach not their own use; but that there is wisdom without them and above them, won by observation."

Richard Hull

My turbo also has hose barbs. It can be either water cooled or air cooled. The packaged unit holding my turbo has a 60 CFM (as I recall) "muffin fan" for cooling.

I would imagine water cooling might be in order if this were a 24-7 running turbo. Doc Bussard's lab had its mechanical and Turbo running 24 -7 when I visited in 2000, courtesy of Tom Ligon, his lab rat. Their fusor was a 3 foot sphere at that time.

Richard Hull

I think it's not so much long-term running but running for significant duty cycle with significant gas flow.

Correct. I will sometimes leave my turbo and roughing pump running all the time. But that's under a pretty hard vacuum, so not much heating once the chamber is pumped down. Heat has not been an issue with my air cooled system.

I think I fried bearings on a varian pump by running it without cooling and it was connected to a SEM, so no gas load. So watch it, I would at least put a muffin fan on it like in the manual.

Both Bob and I have muffin fans on our Turbos. See original post images. Bob claims in the above posts that his pump does use a muffin fan.

Richard Hull

Saw this thread and thought I might ask a question

I have this unit without any cooling assemblies and I’m afraid to try it out without checking the oil. So far I’ve read the manual and I know the process to replace the oil and I know the standard oil needed (TL011). But it’s pretty expensive getting my hands on some.

https://www.duniway.com/part/turbo-oil-100

Is this something I could use? Does anyone have a more economic way?

Thanks,
Ameen Aydan

Edit:

I was dumb and didn't check the MSDS.

https://www.duniway.com/images/_pg/MSDS ... l-100a.pdf

This oil is just repackaged and renamed TL011 oil.

On the brighter side I found a cheaper place to get the oil! Shipping might hurt you though....

https://www.mascom-bremen.de/html/en/va ... 20290.html

I have read the manual and the thing seems to need only a few drops on a wick in the bottom that is just a screwdriver remove wick plate as opposed to some oil reservoir that needs filling. I think this is what I read.

Richard Hull

I just read it too and it seems to say the same thing. But the begs to ask the question of what this little screw is for:

Here, we usually have the heater attached to the chamber, but not at the pump body.

About the venting... you have to wait for the turbo slow down the rotation and then admit air/gas in small amount. If I am not wrong, my pfeiffer performs the first vent operation at 1/3 of the max rotation and then two times more.

Our turbos in the labs: I think the oldest one has maybe 7 years and it is used ocasionally. Never had to go to pfeiffer or the oil changed. Maybe when we note a poor performance, we will think about it.

In your picture (your circled item), that appears to be the access port for the bearing oil wick. I added a few drops of oil to the wick at that location in my unit (it was dated 1988 and never serviced so I figured it needed new oil; hey, the unit, cable and controller ran all of $10), resealed the cap, and after a long bake out and pump down (the oil can have some water from the air if it has been openned previously and stored a long time - mine was) the pump ran great from there on.

The turbo pictured has a vent port (just above your circled plug; the port with the Kf-16 fitting) and that is where dry air can be installed/used to vent the pump after it is turned off. If venting at that location is not used, it is best to let the pump slow down completely before venting - even slowly. There is a danger to bend the blades in these older turbos if one lets in just a lttle too much air. Far better to err on the safe side and just let it stop on its own.

As I prepare to mount my turbo that has remained fallow for 4 years. Purchased from a friend with a working system in 2016. I am ordering the pump oil ($50) which is a wick system oiler rather than a reservoir of liquid oil. I attach images. It seems weird the oil is distributed via a wicking system requiring the oil to rise up the shaft to the bearing via wiping it shaft with a wick!! Of course I do not know what a 90,000 rpm shaft does as traces of oil wipe off the wick. (Climbs the shaft against gravity?)

images show cutaway drawing with supposed conical shaft with wicking wiping the cone in two places. My pump in photo is a small round cylindrical shaft with a wick gasket rubbing at two points being keep wet via its feeding off the cup's oil laden wicking.

Don't mention the debris "bits" in the last photo, it has been removed

Bizarre.

Richard Hull

In at least some cases, the oil is wiped onto the shaft in the form of a thin film, and then centrifugal force drives the oil film outward and upward a shaft that's in the shape of a gently tapered inverted cone.

I have the tiny $50 bottle of oil on order now. I just want to know that once I bolt the turbo to the table it is oiled with the proper oil as access to the oil port is forever not accessible once the system is finished. According to the manual it is good to go for 5000 hours!! This sucker better work!

My lab is a mess as all the old fusor IV bits laden all the benches ready for re-install of fusor IV if this doesn't go anywhere that pleases me. I move slow and will test all along the way for tight vacuum through out. Due to cold and the press of engagements, I'll be lucky to have this thing up and running by spring or early summer. The idea is to use what I have on hand here in the build or cobble up what I need.

Richard Hull

Still mystified as to the need for the heater at the top of the pump. I have never even connected it. Likewise the external fan? I have run the turbo for up to 1 hour, (longest run in the now aborted fusor V effort), and felt the base of the turbo and it was at ambient??? Why the fan..? Is this for labs and processes where the system is left running 24-7? If so, I will never need the fan or the heater?

Still coming up on the wonderment of the turbo. I am very pleased with it, thus far. I had a moment of fear when the first arcs in fusor V turned the controller off automatically. but the reset button, (standby), always worked and restarted....Whew!!....

Richard Hull

The heater at the top is for baking out the pump when removing water vapor or contaminants if it will be used at UHV vacuum levels.
The fan keeps the motor cool when the heater is on, or when pumping very high gas loads, or gasses with high molecular mass such as argon.

Thanks Andrew! Since I have no current aspirations for UHV, the heater is out and the fan will also not be used, due to the total isolation of the turbo in and out with valves. (Stays at low, "fore line" pressure, few microns)

When I shut down I shut the valve to the chamber, let the turbo wind down. (~10 minutes) This leaves the turbo and fore line at about 3 microns. I then valve off the turbo outlet to the fore line. then within seconds I turn off the mechanical pump and slam off pump's exhaust line with a ball valve, then let the pump up to air and immediately reseal the fore line. Thus, the mechanical pump can't "breathe" in or out. (The exhaust line goes out the back of the building)

When I start up, as I hit the mechanical pump switch, I simultaneously open the exhaust line ball valve. I typically hit 10 microns within 20 seconds on the fore line. I then open the outlet valve of the turbo and the fore line pressure might drop or rise by 2 or 3 microns I immediately open the chamber valve and the pressure on the fore line might rise on the TC gauge to 40 microns but within seconds is back down to 10 microns, due to the small cross volume. I start the turbo immediately and within 60-80 second from starting the mechanical pump, the chamber is sub micron (0.0500 micron on the .1 torr baratron) with the fore line TC gauge zero'd out. In the remaining 3 minutes of spin up the baratron drops the chamber to a rather stable 0.002 micron.

Richard Hull

Turbo controllers often include signal lines for rotational speed readout (commonly 0-10 VDC) as well as a switchable line for reduced speed or “soft start.” I find it useful to be able to switch to reduced speed and read out the rotational speed (yet another use for the red HF freebie meters).

Use the fan, it is still needed without the heater. You can fry the bearings otherwise.

The little turbo pumps can be cycled fast back and forth to atmosphere quickly and you can even get them with aerodynamic breaking vents. When these are used in a production setting that ends up as a lot of mechanical PV compression energy and things get hot, so they fan or water cool them.

Fortunately, at shutdown of a fusor, there is no time critical period for stopping a spinning turbo at 90k rpm. It is a walk away and "pop the tab on a cool one" time. Of course, I could run the fan for grins and googlers.... It don't cost much in 'tricity.

Thanks for the added info on the fan usage in up-down rapid operations where they are used in time critical operations.

Richard Hull

Even on stuff where you just leave it on you want a fan.

I run a Varian TV-301 (300 l/s) turbo full time without a fan. I regularly monitor its temperature with an infrared thermometer, and it usually runs 52 degrees C. They offer an optional fan for this pump "for heavy duty use" whatever that means. My guess is that I would get longer bearing life running at a lower temperature, but the pump has well over six years running time on it and only sings a little.

Fans do help extent bearing life on turbos; considering how expensive most turbo's are, a rather good idea to add a fan.