[Phono-L] Repairing a fiber gear

Bob rvuill at comcast.net
Tue Jul 28 11:21:24 PDT 2009


Hi Rich,
    I have good news and bad news.  The good news is that I successfully 
repaired the fiber gear.  I cleaned it first with clock cleaning solution 
and acetone.  When I was sure all the old grease had been removed, I built 
up the damaged teeth with JB Weld.  This was a lot easier to do than I 
thought.  The material can be worked to almost the correct shape before it 
sets up and then cleaned up with a Swiss pattern file after it hardens.  I 
had it almost perfect after one try and after the second application I had 
the gear turning the worm in  the governor perfectly.  The bad news is that 
when I took it apart after the first test there was a fair amount of tension 
on the spring and it appears that I broke it when all the tension let go at 
once.Does any one know how to take the spring barrel apart?  There's a cap 
on the end that extends down the side of the barrel about 3/8".  I'm 
assuming that if I have the gear with the spring arbor on it in the barrel I 
can bang on the end with a hammer and force the cap off.  Does this sound 
correct?  I don't want to mess it up again .  If you know how to remove the 
cap, please advise.
----- Original Message ----- 
From: "Rich" <rich-mail at octoxol.com>
To: "Antique Phonograph List" <phono-l at oldcrank.org>
Sent: Saturday, July 04, 2009 6:27 PM
Subject: Re: [Phono-L] Repairing a fiber gear


> Bob,
> I used to know what those were made out of but right now its a blank.
> The trick is to get the grease out of it so something will bond
> properly.  Once its clean I think I would use a thinned epoxy as a paint
> to build it up and firm up what was left.  Most products sold as epoxy
> are polyester and that will not work.  The easiest place to find the
> real epoxy is a marina and acetone is the thinner for it.  You can thin
> it down so it can be brushed on.
>
> 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
>>>>>>>> _______________________________________________
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>>>>>>>> http://phono-l.oldcrank.org
>>>>>>>>
>>>>>>>>
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