Is this large lab centrifuge capable of spinning? How can I check without a rotor attachment?
June 9, 2011 11:04 AM   Subscribe

Is there any way to find out if the "spin functionality" of a large laboratory centrifuge is operational when said centrifuge was purchased secondhand and did not come with any rotor attachments?

I'm a hardware tech at a smallish biotech lab that often buys equipment "as-is" via auction, etc. Recently we got what seemed to be an excellent deal on a very large centrifuge (Sorvall RC-5B), the catch of course being that it's only REALLY going to turn out to be an excellent deal if it we can establish that it actually works (and fix it if it doesn't). And right now my main concern is that I can't tell if the unit is capable of spinning (which, you know, is sort of important for a centrifuge).

Anyhow, getting to my actual question: the centrifuge (being secondhand and all) did not come with a rotor*. If we are dealing (as I believe we are) with a centrifuge that has an automatic imbalance detection function, is it possible that the thing simply will not spin, period, unless there is a rotor in place? As in, might it be looking not just for "balance" but weight/pressure?

(I have recommended that we try to borrow or rent a rotor from a local supply house and this option is being considered, but I figured I would just try and get a bit of a sanity check in the meantime.

Oh, and I have the product manual but it doesn't specifically say anything along the lines of "the centrifuge post will not spin unless a rotor is installed". It just assumes you have a rotor and says "install the rotor", etc. Which is a reasonable thing for a manual to say, but doesn't help w/ my troubleshooting.

And while I suppose I could try calling tech support, something tells me this is one of those questions where they're not even going to believe I am in fact asking what I seem to be asking because it's so "obvious", meaning I still won't get an answer.)

* The rotor of a centrifuge is NOT to be confused with, say, the motor. I am absolutely certain this centrifuge has a motor. When you look into the chamber what you see is a shaft sticking up in the middle. The rotor is the thing that attaches to the shaft that holds the test tubes, etc. What I want to check is that the motor shaft is capable of spinning, given that the rev/minute needle currently doesn't move even when the device obviously has power, is on, etc. For most devices this is pretty trivial, however, given the large size and power of this unit I don't want to kludge my way into Serious Safety Risk town.

posted by aecorwin to Technology (19 answers total) 1 user marked this as a favorite
Call tech support. There are no dumb questions, especially when it comes to a piece of equipment that will spin at very high RPM and could present a safety hazard if not operated properly.

And besides this, you will have to call them anyway to enquire about getting a rotor.

After working in several labs, I have no sense of shame in asking potentially dumb questions to technical experts, because this is how I get the quickest answer, and often it's something I would have never thought of anyway.
posted by lizbunny at 11:13 AM on June 9, 2011 [1 favorite]

Calling technical support is the correct answer. You will be believed and answered, because this is a totally reasonable question and they would much rather talk to you for five minutes than hear through their legal department that you did something really dumb like what I'm about to suggest.

If you are really dead set against calling tech support, I have once seen someone spin up the centrifuge and then open the chamber. (There was a power failure, he thought he waited long enough for the rotor to stop, but he was wrong.) In order to do this, you have to cut power to the unit and then unlock the door using the emergency override. Check the manual for instructions---it should be in the back under emergency sample recovery or something like that. But, again, this is really dumb and you should call tech support instead.

Also---can you not hear the motor? There's usually a very distinct sound when the centrifuge starts to spin.
posted by d. z. wang at 11:23 AM on June 9, 2011 [1 favorite]

You have to have a rotor, and don't spin it dry.
posted by roboton666 at 11:41 AM on June 9, 2011

by dry I mean the buckets on the rotor need to have containers in them and the containers need to have something in them as well.
posted by roboton666 at 11:43 AM on June 9, 2011 [1 favorite]

If you google "centrifuge accident," you'll see why it's a good idea to call the company, especially for a large/powerful model.
posted by schmod at 12:00 PM on June 9, 2011

> If you google "centrifuge accident,

When I was working in a biochemistry lab our Beckman rep got everybody's attention when he showed up at the loading dock with two large helpers and a big box and announced "Hi! I'm Moe, this is Larry and Curly, we're here to install your ultracentrifuge."
posted by jfuller at 12:09 PM on June 9, 2011 [1 favorite]

So I just spoke with my grandfather in law, who owned several biotech companies in his time (two which I worked for in the early 2000's).

He says the centrifuge should spin, and that you CAN spin it without a rotor.

I stand corrected on my previous posts!
posted by roboton666 at 12:14 PM on June 9, 2011

Response by poster: Wow, thanks for the quick responses. For those who suggested calling tech support... perhaps I should have explained this in my original post) the manufacturer label on this centrifuge is "Du Pont Instruments" and a cursory Googling suggests that Du Pont isn't even in the centrifuge business at all these days. Thermo/Fisher has a Sorvall centrifuge line, it likely they would perhaps have info on an item old enough to bear the Du Pont label?

d.z. wang: Regarding hearing the motor, no, I haven't been able to hear anything that sounds definitively motor-like. I can hear the refrigeration compressor kicking on and running, though, and unless the motor is REALLY loud my guess is that it would be difficult to pick out from the compressor noise. Regardless, currently I would assign highest probability to the motor not running.

roboton666: Your answer is closest so far to what I suspect -- that is, that the motor won't activate unless a (balanced) rotor is detected. This suggests that maybe it would indeed be a good idea for us to borrow/rent/buy a rotor and try it out before assuming any motor/drive problems. And we will definitely make sure not to run it dry!
posted by aecorwin at 12:15 PM on June 9, 2011

Response by poster: ...and, doh, apparently new info came in while I was replying. robotron, thanks again, though now I am wondering if the rotor thing might be model-specific. Which I guess might alter the nature of my question to "how do you get tech support for an obsolete device?" :/
posted by aecorwin at 12:17 PM on June 9, 2011

Response by poster: Er, I meant roboton, not robotron. Danged 80s video games....
posted by aecorwin at 12:24 PM on June 9, 2011

I seem to recall an audible and very distinct whirring noise that rose in pitch as the motor spun faster, but perhaps that was coming from the rotor. I've never tried spinning a centrifuge without the rotor.
posted by d. z. wang at 12:39 PM on June 9, 2011

Du Pont/Sorvall/Kendro have now transmogrified into ThermoFisher Scientific, and whilst the RC-5B is no longer in production, they have similar centrifuges and should have several engineers who can still support this particular model.

Having said that, I agree that the spindle should turn without a rotor installed and as well as producing an audible whine/whirr, there's an rpm needle on the display which should indicate activity.
posted by car01 at 1:51 PM on June 9, 2011 [1 favorite]

Sometimes tech support is remarkably good for legacy lines, and sometimes not. Brands and factories are swapped between the big biotech companies on a very regular basis(until it is all eaten eventually by Fischer), and often tech support is something that can get these companies another sale down the line. I called one company for an old instrument that was at least four mergers in- and they still were able to help me out. Other times, not so much.

I have no idea on your specific model of centrifuge, other than to nth the folks who are recommending caution. Good luck!

on preview, car01 has more knowledge.
posted by rockindata at 1:58 PM on June 9, 2011

I just did a quick image search and found myself thinking, "Ah, one of those."

My experience with a couple centrifuges that look more or less exactly like that the Sorvall RC-5B have all involved me doing what seemed like all the right things in terms of setting a duration and a speed and closing the hatch and telling it to be on its way...AND NOTHING HAPPENING.

And then someone who knows comes along and says "Oh, here", lightly brushes their hand over the panel in back, and it fires right up.

My car pool cohort is in that later group - I'll try to pick her brain on the way home and let you know what I find out.
posted by Kid Charlemagne at 2:01 PM on June 9, 2011

Best answer: Talking to my car pool cohort, she said that some centrifuges require you to tell them what rotor is in place, and will shut down if the weight sensor in them decides that is not in fact the rotor that is in place, but believes the unit you are dealing with is older than that.

She also said you can get a rotor that is good enough for testing from Dove Bids for cheap, but, well, as has been said, Google "centrifuge explosion" for cautionary tales of what happens when you use a rotor that should have been trashed.

Looking at the manual, I'm pretty sure the model you are dealing with requires that the door be closed and latched before it will run, so if the detection mechanism isn't working, that could be your problem.
posted by Kid Charlemagne at 4:44 PM on June 9, 2011

Yeah, nthing a possible door latch issue.
posted by roboton666 at 5:39 PM on June 9, 2011

And one other thing, you should be able to fins a local centrifuge repair technician who can come look at it.
posted by roboton666 at 5:40 PM on June 9, 2011

Response by poster: @ car01: The rpm needle currently doesn't move, but I've learned from experience that sometimes meters/indicators don't work even if the function they're supposed to be measuring is, well, functional. That said, I am definitely at this point pretty convinced that nothing is spinning.

@ rockindata: Heh, I am definitely beginning to notice the "eaten by Fisher" syndrome (I've been at this lab job for several months now). But in any case I just remembered I already have a contact in Fisher's tech support dept (who I talked to a while back regarding a different, smaller, newer centrifuge).

@ Kid Charlemange: Thanks for checking with your carpool cohort! The door latch issue is a *definite* possibility, actually...I shall check on that first thing once I am back at work post-weekend.
posted by aecorwin at 10:36 PM on June 9, 2011

Response by poster: Update: So, I've now examined the door latch mechanism, and as far as I can tell there's nothing wrong with it. The door light is always on when the unit is on, and I'd thought perhaps that was a clue to something being amiss there, but (per the manual) all that light being on means is that the unit is spinning below the "safe to open the door" RPM limit (or not spinning at all, in this case).

On the tech-support front, I've not tried contacting Fisher yet, but I did manage to get in touch today with someone at the secondhand equipment vendor we bought the centrifuge from. This ended up being a very fruitful conversation -- I was told that despite its age this centrifuge does indeed need a rotor installed before it will spin. The vendors actually tried this before selling the unit and were able to verify spinnage-with-rotor, so as far as I'm concerned that variable is taken care of (a good thing, as IMO we're at less risk of wasting money if we go ahead and get a rotor now).

The bad news -- unrelated to the rotor issue, but I figured I'd include it here for the edification of anyone else who may come along seeking info about this or a similar centrifuge model -- is that the vendor is pretty sure the refrigeration compressor needs replacing (or at the very least, extensive and probably expensive repair). And apparently you need a refrigeration license in order to perform this level of repair, which nobody here at the lab has. So, yeah, kind of annoying, but definitely a useful learning experience. Thanks to everyone who weighed in on this thread!
posted by aecorwin at 1:41 PM on June 14, 2011

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