[Phono-L] Repairing a fiber gear

Sun Jul 5 07:37:18 PDT 2009

We had a new fiber gear made for a jukebox I have. He used a CNC machine
and cut it from the old gear, cost about $50. An easier thing may be to
use a gear from a junker Thorens. I probably have one here.
-Barry


Bob wrote:
> Hi Rich,
>    Well I thought it was fixed by replacing the felt but not so.  The
> fiber gear is definitely stripped.  I can still see the gear teeth so
> that if I can build it up with something I can file out the excess an
> hopefully have a useable gear.  The question is what to use to build it
> up.  I guess the first thing to do is clean off the gear completely so
> that whatever I use will stick.  I assume I can remove all the grease
> with something like acetone. Do you know what the fiber gear is made
> from?  This would help in deciding what to use.  Two possible materials
> come to mind.  The first is Weldwood wood filler.  It looks a lot like
> the firer gear and could be worked easily with a small Swiss pattern
> file after it set up.  I'm not sure if it will stick to the firer gear
> material or is strong enough to form the replacement teeth.  The second
> possibility is a clear epoxy.  The advantage to this is that the pattern
> of the original teeth will be visible through it and it will be easier
> to see how the teeth should be filed.  Do you have any suggestions?
> ----- Original Message ----- From: "Rich" <rich-mail at octoxol.com>
> To: "Antique Phonograph List" <phono-l at oldcrank.org>
> Sent: Monday, June 22, 2009 7:32 PM
> Subject: Re: [Phono-L] Repairing a fiber gear
> 
> 
>> If you plan on using the machine a lot it will still help to change it
>> out.  Once the felt gets oil soaked and the old oil oxidizes its pretty
>> much done.
>>
>> Good to hear that it worked out well!
>>
>> Rich
>>
>> Bob wrote:
>>> Hi Rich,
>>>    Well you were right, the felt was the problem.  It was quite
>>> distorted and hanging over the edge of the brass disk on the governor.
>>> .  As the rest of the felt looked pretty good, I only had to reposition
>>> it in the arm that holds it and cut off the excess and reform the front
>>> so that it was parallel with the governor disk.  Thanks for your help.
>>> ----- Original Message ----- From: "Rich" <rich-mail at octoxol.com>
>>> To: "Antique Phonograph List" <phono-l at oldcrank.org>
>>> Sent: Sunday, June 21, 2009 3:19 PM
>>> Subject: Re: [Phono-L] Repairing a fiber gear
>>>
>>>
>>>> Try and change the felt without spreading the bent metal that holds it.
>>>>  Usually you can cut a piece of real wool felt a bit tapered and pull
>>>> it into the clamp without bending them as they tend to break.  Use real
>>>> 100% wool felt or it will fail.
>>>>
>>>> Bob wrote:
>>>>> Hi Rich,
>>>>>     The governor felt is pretty much as you described.  I will change
>>>>> that first.  If it's that easy I owe this list a Big Thank you.
>>>>> Bob
>>>>> ----- Original Message ----- From: "Rich" <rich-mail at octoxol.com>
>>>>> To: "Antique Phonograph List" <phono-l at oldcrank.org>
>>>>> Sent: Sunday, June 21, 2009 12:32 PM
>>>>> Subject: Re: [Phono-L] Repairing a fiber gear
>>>>>
>>>>>
>>>>>> Most of the older fiber gears are destroyed by petroleum.  Clean
>>>>>> it off
>>>>>> and look at it real hard.  Sanding is not going to fix it.  look
>>>>>> at the
>>>>>> felt pad that the governor runs against if its oil soaked and mushed
>>>>>> out
>>>>>> the governor will flutter.  Replace the felt.  Use real felt and not
>>>>>> cheap polyester.  F-1 or F-2 grade felt works.  The felt is easy, the
>>>>>> gear not so.
>>>>>>
>>>>>> Bob wrote:
>>>>>>> I'm restoring a Thorens Excelda.  I've got it running pretty well
>>>>>>> but
>>>>>>> am having a severe problem with wow and flutter.  It's so bad
>>>>>>> that it
>>>>>>> makes listening almost impossible.  The records appear to be
>>>>>>> traveling at a consistent speed but there must be minute hesitations
>>>>>>> that are impossible to see but they surely affect the sound quality.
>>>>>>> The mainspring is plenty strong so that's not the problem and the
>>>>>>> reproducer sounds fantastic on other machines.  The problem appears
>>>>>>> to be caused by excessive wear on the fiber gear that mates with the
>>>>>>> worm gear in the governor.  A friend suggested I clean it and try to
>>>>>>> build up the bad areas with JB Weld.  I'm afraid to do this
>>>>>>> because I
>>>>>>> think it will be very difficult to control and be irreversible if I
>>>>>>> do it wrong.  I've been thinking about cleaning all the grease
>>>>>>> off of
>>>>>>> it and checking over for defects with a magnifier.  If I can see
>>>>>>> areas in the gear thread that are raised I will smooth them out with
>>>>>>> sand paper.  To try to build up an
>>>>>> y areas that look low I will paint on some lacquer or urethane
>>>>>> varnish. As I mentioned earlier, the turntable appears to be rotating
>>>>>> at a consistent speed so It shouldn't take much to true up the teeth
>>>>>> enough to work properly.  I'm looking for second opinions on this
>>>>>> technique or any other technique that you think will solve the
>>>>>> problem.  Thanks
>>>>>>> _______________________________________________
>>>>>>> Phono-L mailing list
>>>>>>> http://phono-l.oldcrank.org
>>>>>>>
>>>>>>>
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