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Western Electric #7 dial "deceleration" issue

Started by novarlynx, March 02, 2016, 12:23:17 PM

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novarlynx

I've got two phones, a 500 and a 554, which both have #7 dials. 500 has a 7D with metal finger wheel and 554 has a 7C with plastic finger wheel. Both of them don't spin at a consistent speed though if you dial zero. They both start fast then slow down slightly as they return to normal. Any ideas to fix this?

Thanks!!

The digital PSTN is so boring now. I wish I could have experienced what it was like to use the Bell System with all its analog wonders.

Well, at least we have museums. Right?

andre_janew

It may be a sign they need cleaning and oiling.

unbeldi

Clean the dial.
Accumulated dust and other microscopic debris hinder the rotation of the governor so that when the main spring tension gets weaker as it unwinds, the main shaft does not have enough torque to maintain constant speed.

I usually remove as many larger parts from the gear box as possible and put the entire dial into an ultrasonic cleaner with a tablespoon or so of Dawn PowerClean.

novarlynx

What should I do to clean it? I don't have the stuff to do ultrasonic cleaning. What's a good alternative?
The digital PSTN is so boring now. I wish I could have experienced what it was like to use the Bell System with all its analog wonders.

Well, at least we have museums. Right?

unbeldi

#4
Quote from: novarlynx on March 02, 2016, 01:55:08 PM
What should I do to clean it? I don't have the stuff to do ultrasonic cleaning. What's a good alternative?

RadioShack used to sell a spray can of electronic contact cleaner, as recently as perhaps two or three years, that doesn't leave a residue after evaporating.   I have used it on dials too, and it did reasonably well.
The force of the jet of the spray will do some cleaning if applied strategically.

novarlynx

I'll take a look and see if I have something similar that'd work. What about blowing some air into it from a compressor?
The digital PSTN is so boring now. I wish I could have experienced what it was like to use the Bell System with all its analog wonders.

Well, at least we have museums. Right?

cloyd

Compressed air is probably the first thing to try.  The electrical contact cleaner does wonders for dirty dials.  I bought mine at Lowe's for about $7.  Get yourself a spot oiler while you are at it and do some research on CRPF about strategic oiling.

Good luck!

Tina
-- I am always doing what I cannot do yet, in order to learn how to do it. - Van Gogh -- 1885

unbeldi

Quote from: novarlynx on March 02, 2016, 03:45:04 PM
I'll take a look and see if I have something similar that'd work. What about blowing some air into it from a compressor?

Most compressor air is polluted with oils from lubrication, but I suppose some might have filters installed.  A compress gas cartridge might be better.   In any event, I doubt that just air alone will work well on the microscopic deposits.

Dennis Markham

There are many topics on this forum about cleaning/lubricating number 7 dials.  Here is just one of them:

http://www.classicrotaryphones.com/forum/index.php?topic=285.15

Do NOT use WD40 on your dials.  When it evaporates there will be a sticky residue that attracts dust.

Good luck.

~Dennis

novarlynx

WD40 isn't a lubricant anyway, it's a penetrating oil. A lot of people think it's a lubricant.
The digital PSTN is so boring now. I wish I could have experienced what it was like to use the Bell System with all its analog wonders.

Well, at least we have museums. Right?

Jack Ryan

Quote from: novarlynx on March 02, 2016, 09:29:00 PM
WD40 isn't a lubricant anyway, it's a penetrating oil. A lot of people think it's a lubricant.

WD40 make many products but even the "classic WD40" is advertised as a lubricant and contains 25% petroleum based oil.

But that doesn't make it good for dials...

Jack

TelePlay

Quote from: novarlynx on March 02, 2016, 09:29:00 PM
WD40 isn't a lubricant anyway, it's a penetrating oil. A lot of people think it's a lubricant.

We have a topic dealing with lubricants used by members. This post is a list of all oils discussed. You can read the whole topic to see what others are using and why.

http://www.classicrotaryphones.com/forum/index.php?topic=7899.msg124966#msg124966

.....

You could always use Dust-Off electronic duster to blow off the dirt. If you don't have an air compressor with filters. Walmart has it or any other electronic store.

http://www.walmart.com/ip/Dust-Off-Electronics-Duster/25596750

Doug

19and41

I cleaned the inner surface of the governor race with a thin swab dampened with 91% isopropyl alcohol.
"Any sufficiently advanced technology is indistinguishable from magic."
— Arthur C. Clarke

oldguy

If all else fails you can send it to Steve Hilz, good work at a good price.
Gary