Eppendorf 5415 centrifuge: How to remove the rotor?

[jarlemag]

I recently bought an Eppendorf 5415D centrifuge, and have tried to remove the rotor for cleaning and inspection. I don't have a rotor key of the kind that is sold by Eppendorf, but the item description at http://www.capitolscientific.com/Eppendorf-022667181-Rotor-Key-for-Microcentrifuge-Models-5415-D-5415-R-10mm-Socket-Wrench seems to indicate it's just a standard 10 mm socket wrench, so I bough one of those. (https://www.amazon.com/gp/product/B0028N57SW). I attempted to use the socket wrench on the hexagonal part in the centre (see the picture), but that just makes the whole rotor turn. I tried to keep the rotor in place while turning the wrench, but that didn't work either (I couldn't keep the rotor still).

If I try to lift the rotor upwards, the centrifuge hangs from it and I'm worried about damagaging it so I didn't try that very hard.

The centrifuge manual (http://www.nist.gov/ncnr/upload/Eppendorf_5415R_Centrifuge_Manual.pdf) doesn't go into detail about how to remove the motor. It mentions bending the rotor to one side if it's stuck, but how do I know if it's stuck in the way which is solved by doing that? 

What do I need to do?

Picture of the rotor: https://drive.google.com/file/d/0B9aq85qBYTsWZm5tamh0QWRJSFE/view?usp=sharing

Best regards,

JP

[Mega [Andreas Stuermer]]

I don't know about this model, but have you tried screwing the thing in the other direction? I once took off a rotor and for some reason the screw had to be turned clockwise to release the rotor.

[Nathan McCorkle]

Have you tried removing the circlip and seeing if the rotor can pull
off with that alone removed?

You can get by with needle-nose pliers sometimes, but they make
special pliers for circlips/c-clips:
http://www.crawfordtool.com/KN4421J21h_200l.gif

The other thing would be to try seeing if there were flat sections
machined below the rotor on the spindle, or a hole drilled through
that you could place a metal pin through to lock rotation. If neither
of those, then I might try an electric/pneumatic impact driver (they
apply quick rotational pulses to the drill bit/socket, one or two
'taps' might free it enough to finish by hand).

Of course try opposite rotation as Andreas mentioned first, too.

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[Jeebus 420]

What you have described is the correct way to remove the rotor. You put the wrench around the hexagonal part and turn it opposite the rotor. It could be difficult from being over tightened in the past or perhaps you have been turning it the wrong way. It's been a while, but I think the rotor itself should turn turn counter clockwise to unscrew it while the wrench goes clockwise.

[John Griessen]

On 08/19/2016 01:18 PM, jarlemag wrote:
> I attempted to use the socket wrench on the hexagonal part in the centre (see the picture), but that just makes the whole rotor
> turn. I tried to keep the rotor in place while turning the wrench, but that didn't work either (I couldn't keep the rotor still).

The rotor will have holes for tubes. You may need to get something non-damaging to lodge in those holes
to use for a lever against the hex wrench. Something as long as the hex wrench with wood dowels
to fit in the holes. Or someone else with large strong hands to grip it?

Try not to put any side force on the rotor. Try to get a grip so you can use the wrench perpendicular to the rotor axis so
very little side force is on the rotor bearing.

[jarlemag]

Thanks for the advice everyone. I've tried turning in both directions, but the rotor just turns in either direction, so without being able to stop the rotation it's hard to tell if any direction feels better. I think I might need some kind of tool to get better leverage/immobilize the rotor. I will give an update if I succeed.

Best regards,

JP

[Mitchell Coplan]

I have the same problem.  I was able to remove the circlip and the hexagonle part using the methods described in the group.  I thought I would now be able to pull the rotor out, however it still seems to be screwed in sowewhere. Does anybody know the next step?  I have attached a picture to show you what my centrifuge looks like now. Any advice would be appreciated. 

[John Griessen]

On 02/07/2017 10:23 AM, Mitchell Coplan wrote:
> I attempted to use the socket wrench on the hexagonal part in the centre (see the picture), but that just makes the whole rotor
> turn. I tried to keep the rotor in place while turning the wrench, but that didn't work either (I couldn't keep the rotor still).
> If I try to lift the rotor upwards, the centrifuge hangs from it

OK. That all sounds like what it looks like, but I have no personal experience with these, so I could be wrong.

What it looks like from the two angled views of the rotor with all parts on , and some parts off is
that the center hex wrench is for unscrewing the rotor. The small center shaft with the hex socket looks
to be threaded. The nut you removed is a lock nut.

Which way do the threads undo? clockwise or counter-clockwise? To undo the rotor, you will want the
small center shaft to go down below what we can see, not come out like a screw. When you determine the correct way to
loosen the small center shaft, you can put a philips or posidrive screwdriver in one of the vial holder holes
in the rotor, and use it as leverage to turn the hex wrench. If you put the small length of the hex wrench
in the hex socket, the long end will give you more leverage, and put the screwdriver 5 or 6 cm from that
and squeeze with thumb and fingers and probably it will give way. (Once you know the correct turning direction
to loosen the small center shaft). You cannot succeed without getting the undo direction right.

A small amount of penetrating oil on the threads of the small center shaft may help, especially if left overnight.
For a strong thing like a centrifuge shaft, you can safely put 4 kg force on it at the edge, by way of the screwdriver in
a hole. Do that at many different angles/positions. Then try undoing again.

If that all fails, get a hair dryer and heat the rotor up, the put an ice cube on the small center shaft,
then rapidly try the undo motions again. The heat and ice will literally lessen the force of an interference fit,
when done to the right parts. The ice cube should be melted on, (with the thing sideways or partly upside down), for
only ten seconds, then get the undo forces going in another 3 seconds, or it all goes back to normal, temperatures averaging out,
(stuck).

[samwichse]

I recently had this problem. I found that standard size sharpies fit perfectly in the 1.5ml microcentrifuge holes. There was no reverse thread. Standard righty-tighty, lefty-loosey.

Mine was really stuck on there, but after cranking it way harder than I should have to, it popped free.

I have another eppy that the rotor is totally stuck to the shaft. The screw is loose, but it WILL NOT come loose. Soaked it in WD-40 even. No dice.

[CPM]

Hola a todos

También tengo ese problema. Aunque  el tornillo que sujeta el rotor al eje de la centrífuga no puedo extarer el rotor. Eso se hace con una herramienta denominada "extractor". Los extractores son de varios tipos. Una de ellas es de la siguiente forma: pieza cilíndrica que por un extremo presenta rosca externa y es un o dos centimetros  hueca por el centro y por el otro lleva una marca para poder enroscar la pieza en el rotor. Si os fijais, el rotor tiene una rosca rodeando el eje y una tureca acabada en una bola central que lo fija al eje del motor. La tuerca puede aflojarse y no se sale porque tiene una arandela que se lo impide. Pero al aflojar esa tuerca se queda totalmente libre. Bien, esto consiste en aflojar la tuerca de fijación un poco sin liberarla del todo y roscar el extractor en el rotor hasta que la parte no hueca del mismo haga fuerza sobre la cabeza redonda de la tuerca de fijación (que es más elevada). De esta forma se hace una fuerza inversa sobe el eje hacia abajo y sobre el rotor hacia arriba que lo libera. Con liberarlo un poco, uno o dos milimetros es suficiente. Entonces se desenrrosca el extarctor, se termina de aflojar al tuerca de fijación y se extrae el rotor hacia arriba. 

Estro mismo se puede conseguir con un extractor que sujete el rotor por 3 puntos en su parte más externa y haga fuerza sobre el eje del motor.

Esto es sencillo. pero ¿quien tiene o dónde puedo encontrar ese extarctor?

[Nathan McCorkle]

On Wed, Sep 20, 2017 at 11:38 PM, CPM <carlos...@gm.uca.es> wrote:
> Hola a todos
> También tengo ese problema. Aunque el tornillo que sujeta el rotor al eje
> de la centrífuga no puedo extarer el rotor. Eso se hace con una herramienta
> denominada "extractor". Los extractores son de varios tipos. Una de ellas es
> de la siguiente forma: pieza cilíndrica que por un extremo presenta rosca
> externa y es un o dos centimetros hueca por el centro y por el otro lleva
> una marca para poder enroscar la pieza en el rotor. Si os fijais, el rotor
> tiene una rosca rodeando el eje y una tureca acabada en una bola central que
> lo fija al eje del motor. La tuerca puede aflojarse y no se sale porque
> tiene una arandela que se lo impide. Pero al aflojar esa tuerca se queda
> totalmente libre. Bien, esto consiste en aflojar la tuerca de fijación un
> poco sin liberarla del todo y roscar el extractor en el rotor hasta que la
> parte no hueca del mismo haga fuerza sobre la cabeza redonda de la tuerca de
> fijación (que es más elevada). De esta forma se hace una fuerza inversa sobe
> el eje hacia abajo y sobre el rotor hacia arriba que lo libera. Con
> liberarlo un poco, uno o dos milimetros es suficiente. Entonces se
> desenrrosca el extarctor, se termina de aflojar al tuerca de fijación y se
> extrae el rotor hacia arriba.
> Estro mismo se puede conseguir con un extractor que sujete el rotor por 3
> puntos en su parte más externa y haga fuerza sobre el eje del motor.
>
> Esto es sencillo. pero ¿quien tiene o dónde puedo encontrar ese extarctor?
>
>

auto-translated by Google:
"""
Hello everyone
I have that problem too. Although the screw holding the rotor shaft of
the centrifuge rotor can not extarer. This is done with a tool called
"extractor". Extractors are of various types. One is as follows:
cylindrical part which at one end has external threads and is a hollow
or two centimeters from the center and the other carries a label to
thread the workpiece in the rotor. If you look, the rotor has a thread
surrounding the axis and tureca finished in a central ball that
fastens to the motor shaft. The nut can become loose and not out
because it has a washer that prevents it. But by loosening the nut is
left completely free. Well, that is to loosen the fixing nut slightly
without releasing all and thread extractor in the rotor until the
hollow portion thereof not exert force on the round head of the nut
(which is higher). Thus a reverse force sobe shaft downward and upward
on the rotor is it relieves. To release a bit, one or two millimeters
is enough. Then the extarctor desenrrosca, it ends loosening the lock
nut and the rotor is drawn upwards.
Estrus same can be achieved with an extractor handle the rotor by
three points in its outermost part and exert force on the motor shaft.

This is simple. but who have or where I can find that extarctor?
"""

Hmm, so you first need to know what kind of thread and what the
thread-to-thread pitch is. Then it sounds like a custom tool needs to
be machined. Or if one can be found, used, like on ebay... at least we
know what to look for.

:) thanks

[jerry maxwell]

Simple fix here. Loosen the top nut (counter clockwise) and spray a wee bit of WD40 under the nut in between the ends of the c-clip. Let it set for a couple minutes and viola! the rotor comes right out. The problem is caused because the rotor spindle binds to the rotor. WD40 makes quick work of it.  Jerry, CSI Sonora California

On Friday, August 19, 2016 at 11:18:51 AM UTC-7, jarlemag wrote: