Testing a Turbo without controller

For Short Term Learning Discussions ONLY. This area is for CURSORY questions and connecting with other users ONLY. ALL technical contributions need to be made in the appropriate forums and NOT HERE. All posts are temporary and will be deleted within weeks or months. You should have already search the extensive FAQs in each of the forums before posting here as your question may already be answered.
Matt_Gibson
Posts: 505
Joined: Thu Sep 23, 2021 10:36 am
Real name: Matt Gibson

Testing a Turbo without controller

Post by Matt_Gibson »

Hi everyone, I have been back and forth on whether or not I should go with a diffusion pump or a turbo. Upon seeing the Turbovac 50, I am leaning towards a turbo (among all of the other perks).

The only problem I have is that I don’t have a controller. How might I go about testing the pump without the controller? It’s either spend $600-thousands on a tested one, or a few hundred on an untested one.
richnormand
Posts: 307
Joined: Sat Aug 27, 2005 8:30 am
Real name: rich normand

Re: Testing a Turbo without controller

Post by richnormand »

You need to talk to Gustavo:
viewtopic.php?f=10&t=14207
Matt_Gibson
Posts: 505
Joined: Thu Sep 23, 2021 10:36 am
Real name: Matt Gibson

Re: Testing a Turbo without controller

Post by Matt_Gibson »

Change of plans, I got a Pfieffer TMH 071P with controller on eBay. It looks to be in great condition, but we’ll see once it arrives. $250 seemed like a good enough deal, no?

Is it safe to briefly power it up without it being connected to, and under, a high vacuum? I understand that letting it spin up to its max rpm in air is going to ruin it, but what about letting it spin up for a few seconds?
User avatar
Liam David
Posts: 518
Joined: Sat Jan 25, 2014 5:30 pm
Real name: Liam David
Location: PPPL

Re: Testing a Turbo without controller

Post by Liam David »

There's no issue letting it spin up for a few seconds in air. If it works, for $250 it's a steal.
User avatar
Richard Hull
Moderator
Posts: 14991
Joined: Fri Jun 15, 2001 9:44 am
Real name: Richard Hull

Re: Testing a Turbo without controller

Post by Richard Hull »

A few second spin up in air will tell you the motor and controller are most likely OK.
The condition of the bearings is another matter. You will need to spin it up fully under vacuum to be absolutely sure about them.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Matt_Gibson
Posts: 505
Joined: Thu Sep 23, 2021 10:36 am
Real name: Matt Gibson

Re: Testing a Turbo without controller

Post by Matt_Gibson »

Sounds good, guys. I’ll see if it spins up a bit without any vibration. If so, I’ll probably spring for the lubrication replacement kit ($105) since I don’t know how long it’s sat for.

$250 also seemed like a steal, so I’m super skeptical. I can return it if it doesn’t work, so not too much risk. I won’t know about the bearings at full speed till I can settle on a backing pump.
User avatar
Finn Hammer
Posts: 298
Joined: Sat Mar 05, 2016 7:21 am
Real name: Finn Hammer
Contact:

Re: Testing a Turbo without controller

Post by Finn Hammer »

Matt,
Read this thread
viewtopic.php?f=10&t=12172&p=79179&hili ... fer#p79179
for tips on getting the turbo running.
It has a funny startup sequence where it first goes forward a bit, then backwards a bit then stalls before spining up.
Don't worry about ruining it by lettting it spin. The controller is a smart cookie, and monitors the current draw to detect that it is running in atmosphere. It stops at around 2000rpm.
I have an identical turbo, and am using the diaphragm pump to match. Highly recommended since the turbo can function at up to 15 torr. Since the diaphragm pump bottoms out at 2 torr, the 13 torr window can be used to stop the backing pump momentarily, provided you build your pumping station with a buffer tank in the forellne.
(See the "bell and whistles" thread for deails.) The forepump can then be controlled by a 901P and a solid state relay.
Really blissfull to sit by the Fusor without the backing pump making it's noises.

Cheers, Finn Hammer
Matt_Gibson
Posts: 505
Joined: Thu Sep 23, 2021 10:36 am
Real name: Matt Gibson

Re: Testing a Turbo without controller

Post by Matt_Gibson »

Hi Finn,

Looks simple enough! Let’s hope I did good…

As for using a diaphragm pump as the backing pump, how well would it work if I had to “backup and punt” and go to a diff pump if this little turbo is junk? Would a diaphragm pump work okay with a diff pump?

Thanks,
Matt
User avatar
Finn Hammer
Posts: 298
Joined: Sat Mar 05, 2016 7:21 am
Real name: Finn Hammer
Contact:

Re: Testing a Turbo without controller

Post by Finn Hammer »

Matt,

Nope, The diaphragm pump will not pump deep enough for a diff pump.

Cheers, Finn hammer
Matt_Gibson
Posts: 505
Joined: Thu Sep 23, 2021 10:36 am
Real name: Matt Gibson

Re: Testing a Turbo without controller

Post by Matt_Gibson »

Gotcha,

I’ll see how well this turbo runs in a few days before I make any more acquisitions.

-Matt
Matt_Gibson
Posts: 505
Joined: Thu Sep 23, 2021 10:36 am
Real name: Matt Gibson

Re: Testing a Turbo without controller

Post by Matt_Gibson »

It works! It moved the blades in one direction only, then paused, then spun up. I could feel a strong breeze coming out of the outlet. Green light lit steady on the controller.

Any way to guess at the bearings health? There was no vibration or any weird noise. It’s pretty quiet.
User avatar
Finn Hammer
Posts: 298
Joined: Sat Mar 05, 2016 7:21 am
Real name: Finn Hammer
Contact:

Re: Testing a Turbo without controller

Post by Finn Hammer »

Matt,
Congratulations.
Put the turbo on the table without power connected.
Rotate the housing 30 degrees back and forth.
If the rotor stands still, the bearing is probably fine.
If the rotor follows the housing, it is shot.
I can find where to get it if you need it.

Cheers, Finn Hammer
Matt_Gibson
Posts: 505
Joined: Thu Sep 23, 2021 10:36 am
Real name: Matt Gibson

Re: Testing a Turbo without controller

Post by Matt_Gibson »

Hmm, I’m not sure I’m doing this right…

The rubber feet cause it to bounce around as I attempt to rotate. This causes the rotor to move around. So, it seems to stay in place and then move a bit as the rubber feet catch and release.

What all is involved if the bearing is bad?
User avatar
Finn Hammer
Posts: 298
Joined: Sat Mar 05, 2016 7:21 am
Real name: Finn Hammer
Contact:

Re: Testing a Turbo without controller

Post by Finn Hammer »

Matt,

This is a test to see if the friction in the bearing is excessive, which may or may not reveal a bad bearing.
Try to put the pump on a couple of polyethylene bags and some cardboard on top, that should reduce the friction between rubber feet and table.

Cheers, Finn Hammer
Matt_Gibson
Posts: 505
Joined: Thu Sep 23, 2021 10:36 am
Real name: Matt Gibson

Re: Testing a Turbo without controller

Post by Matt_Gibson »

Hi Finn,

Let’s assume the bearing is bad…Is there a replacement available other than the $700 one from ajvs?

If I recorded it running, could you tell by the sound if the bearing is bad?

Edit: Does the analog output pin give an rpm speed?

Thanks!
Matt
User avatar
Finn Hammer
Posts: 298
Joined: Sat Mar 05, 2016 7:21 am
Real name: Finn Hammer
Contact:

Re: Testing a Turbo without controller

Post by Finn Hammer »

Matt,

https://alpinebearing.com/ I got a bearing for around 100US$.
Yes, the analog out gives the speed, but you should read the manual about that.
I and others might be able to detect a bad bearing from a recording. Make a good one and post it to youtube.

Cheers, Finn Hammer
Matt_Gibson
Posts: 505
Joined: Thu Sep 23, 2021 10:36 am
Real name: Matt Gibson

Re: Testing a Turbo without controller

Post by Matt_Gibson »

Thanks, Finn. I’ll make a good video when I get home. Looking at your YouTube video, it appears to act, and sound, exactly the same. Maybe I got lucky? $100 isn’t too bad…Is there a part number that you have handy?

Edit: I see they have drop down menus that select the bearing for the turbo, nice.
Matt_Gibson
Posts: 505
Joined: Thu Sep 23, 2021 10:36 am
Real name: Matt Gibson

Re: Testing a Turbo without controller

Post by Matt_Gibson »

Here is a video of it spinning up. You’ll have to excuse the psu fan that comes on in the beginning. I cut it off early as the rotor takes awhile to come to a stop and doesn’t make much noise that would be useful to hear.

https://youtu.be/7S7xj0gOLVA

Here is a video of me shifting it around with the power off.

https://youtube.com/shorts/NGx8Qpe9Q18?feature=share

-Matt
Matt_Gibson
Posts: 505
Joined: Thu Sep 23, 2021 10:36 am
Real name: Matt Gibson

Re: Testing a Turbo without controller

Post by Matt_Gibson »

Any ideas as to why this swaglok was used to replace the dn16 that would have originally been on this pump? I’m guessing this isn’t going to be a great way to connect this turbo to my foreline pump (it has Kf25 flanges).
0BADAB92-C7CC-4697-AD0D-3433A7A1DEFF.jpeg
User avatar
Richard Hull
Moderator
Posts: 14991
Joined: Fri Jun 15, 2001 9:44 am
Real name: Richard Hull

Re: Testing a Turbo without controller

Post by Richard Hull »

Wow! that is quite a strangle hold on the fore line.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Matt_Gibson
Posts: 505
Joined: Thu Sep 23, 2021 10:36 am
Real name: Matt Gibson

Re: Testing a Turbo without controller

Post by Matt_Gibson »

No kidding! Makes me envision trying to suck a milkshake through a coffee stirrer. I have no idea what they were using this pump for…

I haven’t been able to find a 1/4” BSPP to Kf25 that isn’t Chinese, so I may have to do a few conversions ($$$$$$) to get it to pair up with my Edwards e2m2 (Kf25).
User avatar
Finn Hammer
Posts: 298
Joined: Sat Mar 05, 2016 7:21 am
Real name: Finn Hammer
Contact:

Re: Testing a Turbo without controller

Post by Finn Hammer »

Matt,
You have a good pump, congratulations, it is a small gem.
The reason for the swagelock fitting could be, that the pump is content with 6-8mm tubing in the foreline.
This dimension gives an adequate flowrate at the pressure interval that the turbo's drag pump stage accepts.
I have an identical pump, and backed by a MVP 015-2 diaphragm pump, the foreline pressure is regulated between 4 and 10 torr by a 901P foreline pressure transducer.
With a one liter foreline buffer tank, this gives me 10-15 minutes of near silent bliss, with only the turbo running, only interrupted for a couple of minutes, by the MVP 015-2 roughing the line down to 4 torr again.
The manual states that 6 torr is the maxumum foreline pressure for H2, but this is the requirement for attaining 1 x 10E-7. But pumping at 20 Microns is another matter. I sat it to 10 torr by monitoring the current draw. at 10 torr it starts drawing more than 1.5A, and starts to heat up slightly, so as a safety measure, 10 torr is the limit.

Cheers, Finn Hammer
Matt_Gibson
Posts: 505
Joined: Thu Sep 23, 2021 10:36 am
Real name: Matt Gibson

Re: Testing a Turbo without controller

Post by Matt_Gibson »

Hi Finn,

Thanks for the reassurance! I got a second on these for a spare, but the bearing is definitely shot. Would you consider a $150 bearing to be worth it? I have $215 into the second one…

As for the swagelok, would you say that this pump is fine with this on it? Should I go about converting this swagelok to mate with my Kf25 or should I go another route? My Edwards e2m2 can get down to 4.5 microns in 15 mins….

Here is how I tested the Edwards pump ( I added in some various fittings to give it a better work out):
Attachments
E2DD3BBC-AC3A-4537-8003-A6B0B121B5B7.jpeg
User avatar
Finn Hammer
Posts: 298
Joined: Sat Mar 05, 2016 7:21 am
Real name: Finn Hammer
Contact:

Re: Testing a Turbo without controller

Post by Finn Hammer »

Matt,

150$ seems reasonable, and probably better to stick with KF in the foreline.

Cheers , Finn Hammer
Matt_Gibson
Posts: 505
Joined: Thu Sep 23, 2021 10:36 am
Real name: Matt Gibson

Re: Testing a Turbo without controller

Post by Matt_Gibson »

Man o man is it hard to find kf/qf to bspp adapters!!!!

I found a Kf16 to bspp 1/4” from idealvac for $100 shipped, but will need a Kf16-Kf25 plus clamps, centering rings…

Dern…

Anyone have experience with mtixtl? They have a Kf25 to bspp 1/4” for $50 but want $30 to ship it…
Post Reply

Return to “New User Chat Area”