Help with Beogram 1500 deck motor.

[Mikeymushradio]

Hi All,

This is the version consisting of record-player plus amplifier, the actual beck being a Beogram 1000. I have been asked to look at the deck by a friend who wants to use it to copy some vinyl onto cd's.

The problem is the turntable is running very slowly,even after dismantling and cleaning the motor bearings and speed control most of which were gummed up.

The motor ran ok after the re-build yesterday but after a nights rest it has returned to running slow again, it appears to be fed from the mains TX but i have no details of the voltage etc ,has anyone had experience of this,i had exactly the same fault on one of these years ago and that one actually beat me but this one is n't mine so would like to repair it.

The motor /turntable etc are not fouling anything and are quite free and the belt appears in good condition ..........any ideas

Mike

[mickjjo]

Just a thought, When you stripped the motor did you thoroughly clean out the bearings and the shafts?. I have sorted many Collaro and Garrard motors that were running slow, even after oiling, by polishing the shaft and the inside of the bushes with fine abrasive paper before re-oiling. Always works for me. I believe the old lubricant hardens over time and causes tightness in the bearings leading to partial or total seizure. .

Regards, Mick.

[Roy]

This suggestion may be too late if you have already written off the job, but if the motor is a conventional shaded-pole type, and you had to dismantle it to attend to the bearings, the problem could possibly be due to slight misalignment of the rotor.

I had a similar problem with a Collaro motor, described in this thread:

https://www.vintage-radio.net/forum/...ead.php?t=4690

It started with a seized motor, which had to be dismantled for repair, disturbing the alignment. Upon reassembly, it would run slow until fully warmed up. I had to realign the rotor with great care before it would run reliably at the correct speed. Once correct alignment was achieved, everything was fine, but it took several attempts.

Roy

[Mikeymushradio]

Hi Mick and Roy, thanks for the suggestions but the motor was running slow before stripping and the top bearing was not disturbed other than to pull out the rotor to clean and re lubricate.

After the initial clean/lube it worked ok and I left it running set at 78 for a couple of hours which I thought would settle things in, but after switching off and on again it would still only run slowly.

I have reassembled the unit again but may have another go with it later as I don't like to be beaten with anything.

Thanks again, Mike

[mieite]

Hi
Here is some info on the motor
http://www.beocentral.com/products/bg1000
Should be same as in 1500
Regards
Nisse

[Nickthedentist]

So maybe it's something to do with the axial centrifugal speed regulator

[Roy]

It does sound a little more complex than the Collaro motor, which definitely lacked an axial centrifugal speed regulator.

Sometimes over-complication and reliability don't go together. The same principle applies to motor vehicles, I have discovered, after being stranded at the roadside rather more times than enough.

None of likes to be defeated by a recalcitrant piece of equipment, but occasionally the most useful skill is knowing when to give up.

Roy (ex S**B driver)

[Mikeymushradio]

Hi Nick, no i have already thought of that and tried the motor with it disconnected, it was actually seized originally and i thought i had the answer but alas no, there is no difference to the speed with it removed altogether (it just varies the selected speed by a little either way from the norm when working correctly)
Mike

[Stewart]

The following is a direct qoute from my friend who runs the Beocentral site mentioned earlier. He's had this slow running problem a good few times!

"........B&O are unlikely to be able to help, the motor was always considered a sealed unit that was returned to the factory when defective (see "radio & television servicing 1967 > 68). However, Here is the answer:

The lubricant that is soaked into the two phosphor-bronze bearings in the motor has degraded and must be replaced. You will need a press (or a very hot soldering iron) to remove the motor top pulley so gain access to both bearings*.

One the bearings are removed from their housings (carefully unfold the metal) they should be boilled in engine oil for a few minutes. This serves two purposes, firstly the old oil is thinned and expelled, secondly the thin new oil is soaked into the porus material. Let the bearings cool in the oil before removing them. Clean the shaft and the foam oil absorbers in petrol to ensure all traces are removed. Re-assemble carefully, noting that the govenor* is soldered together in a jig so if you damage it you will not be able to make it run true again. Dampen the oil absorbers with a small amount of engine oil to stop them drawing out that which is in the bearings themselves.

Check all the other bearings in the speed change mechanism move easily, especially those that allow the idler wheel assembly to rotate so that it can be drawn under belt tension onto the motor pulley.

* There are two versions of the Beogram 1500, assuming that you are reffering to the Beogram 1500 "record player" (has a built-in amplifier, about 1967 to 1972), not the Beogram 1500 turntable (late '70's). Of the former type, the original "Beogram 1500" has a chrome speed change knob with three speeds, the later has a black knob and only two speeds. Repair procedures are similar for both, though the later type has no govenor and the pulley is held in place by a grub screw.

Best of luck! ......"

[dave8989]

Hi all,

Have just finished re fitting the Beogram 1500. I have boiled the bearings in oil and at the moment she is working fine. I wont really notice anything until I have run her for a few days. She however picked up speed once the arm was lifted, so I didnt have to wait for the platter to catch up speed, and wait before lowering the needle, as I did before, so thats promising. Will up date again in a few days time.

Cheers Dave

[dave8989]

Dear Mike

I have played my beogram now for approx 5 hours, no trouble, she maintained her speed through out. The biggest test was this morning, playing her cold , and she was fine. So it works. At last. So oil boiling bearings works.

[ppppenguin]

By chance I visited Mike Solomons (London Sound) today for the first time in many years. We were swapping various stories and I mentioned the Beo 1500 problem. Sure enough he's seen it before and fixed it. The problem is old lubricant in the bearings. His approach seems rather dramatic, to heat/burn it out with a small blowtorch. Then clean off the gunge with lighter fluid. Potentially repeat up to 3 times to get it all out. Then soak in oil. The boil in oil approach sounds safer to me! It's possible that the boiling may need to be repeated to displace all the old lubricant.

[Mikeymushradio]

Hi again, many thanks for all the suggestions and the latest one regarding boiling oil seems to do the trick i will certainly be trying this when time permits,it just goes to prove that where there is a will there is a way,i have been in this game for nearly 50 years and am still learning !.
Once again many thanks to everyone who contributed and to Pauls excellent forum.
I will post the results when i can get chance to work on the motor again.

Mike

[Mike Phelan]

It is a known method to heat the oil and leave it soaking overnight when using sintered bronze bearings, like most ones in deck motors and synchronous clocks.

Looking in some ancient car servicing literature of mine, it was recommended when you renewed dynamo or starter bushes.

Sintered bearings are made from compressed powder and absorb oil like a sponge, faster if the oil is hot.

Cleaning it first is essential, but I would question burning it off in case the interstices of the sintering became full of carbonised oil, that would be impossible to remove. I use an overnight soak in petrol or IPA.

[Nickthedentist]

Originally Posted by Mike Phelan

Cleaning it first is essential, but I would question burning it off in case the interstices of the sintering became full of carbonised oil, that would be impossible to remove. I use an overnight soak in petrol or IPA.

Would an ultrasonic bath be of any use for this, Mike?

Nick

[Mike Phelan]

I would think it would be ideal, Nick
Many clock folk always use them.

[dave8989]

Hi Guys

Thought you would all like to know that Bang/Olufsen did get back to me.

Dear Sir.

Thank you for your email dated 14 of March 2006. We apologize very much this late reply.

We are pleased to see that you are the owner of a Beogram. It sounds as if the bearing in the motor needs to be cleaned and greased again.

It that does not help, please feel free to contact your local dealer via the following link:

http://www.bang-olufsen.com/web2/sto...n=3&country=GB

Kind regards
Bang & Olufsen a/s

Cheers Dave