turntable Beocenter 3500

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Vandenberg Posted: Thu, Feb 9 2017 4:37 PM

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I recently bought a Beocenter 3500 and after cleaning and lubricating (the switches)  the amplifier- and tuner section it works fine.

The turntable took more work, but I could get it working again.

There is one problem that puzzles me however: the motor is running too slow.

I know you can finetune the speed, but the motor speed is way too slow (about 30percent).

If I switch to 45rpm I get only about 30rpm.

Everything is lubricated and running smooth, no extra friction.

Is there a way to speed up this motor?

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Dillen replied on Thu, Feb 9 2017 5:51 PM

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Vandenberg:

Everything is lubricated and running smooth, no extra friction.

Not correctly. Not smooth enough.
Typical symptoms.
Keep in mind that these motors use sintered bronze bearings, they are not lubricated on the outside but
on the INSIDE of the material. The lubricant is pressed in to the poreus material from factory.
Any oil you can put on the bearings from the outside (the conventional way) will only work for hours, perhaps a few days, then
you will be back to the problem again.
You will have to clean out the remains of the old oil and press in new.
Rudy (Beolover) shows how to do it with Beogram 4002 motor bearings on his blogspot.
Search this forum and you will find more threads about this.

Martin

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Vandenberg replied on Thu, Feb 9 2017 6:14 PM

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Thank you Martin,

I will do that.

Hans.

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Vandenberg replied on Fri, Feb 10 2017 6:49 PM

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Well Martin it did the trick.

I took a good look at the video that Rudi made especially the vaccuum bottle, and read a few more posts about the subject.

In one of these Jacques wrote that he also heated up the bearings and oil "au bain marie", and I decided to combine these two methods.

I remembered that I had somewhere a ´winebottle vaccuum set` and hoped that that would create enough underpressure.

It did, after heating the bottle and oil to about 70 degrees I applied the winevaccuumpump and sure enough a lot of small bubbles started to come up.

I let it stand there on slow heat for about 5 hours till no bubbles came out of the bearings anymore.

Half an hour ago I put everything together again and the platter runs at a beautifull 33rpm.

So thanks Martin, Rudi and Jaqcues.