Author Topic: 7D Dial Cleaning & Lubrication  (Read 13910 times)

Offline WesternElectricBen

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Re: 7D Dial Cleaning & Lubrication
« Reply #15 on: October 09, 2013, 10:42:56 PM »
I am working on my first restore, a 2/57 WE 500. Over the years a 9/65 9C-3 dial was installed (plastic finger wheel).
The dial I wish to use (5-56 7D-3) was hanging and had a loud gear meshing noise. I took it apart, cleaned and lubed per this thread. Now the dial is as smooth as silk, has the feel and sound I remember from my youth.
Before I install it in the phone I have one question.
In what position does one set the plastic cam that controls the pulse?


Yes, notice what I circled (the plastic is not perfect circle) and it has to be in that position as well as the pointer I used to show how the "hand" looking thing should be flush with the contacts.

Hope that helps!
Ben
« Last Edit: October 09, 2013, 10:48:52 PM by DavePEI »

Offline WesternElectricBen

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Re: 7D Dial Cleaning & Lubrication
« Reply #16 on: October 09, 2013, 10:44:14 PM »
Pic one is incorrect

Pic two is correct

Offline DrBob

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Re: 7D Dial Cleaning & Lubrication
« Reply #17 on: October 09, 2013, 11:21:30 PM »
Thanks for the reply. I currently have it set at about the 11 o'clock position which seems close to your first picture. The last correct photo you posted shows it at about 9 o'clock?
If I count the contact "opens" when the dial returns to home the number of opens = the number dialed.
Is it good where it is or should I set it counter clockwise a tad?
Photo attached

Offline Dennis Markham

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Re: 7D Dial Cleaning & Lubrication
« Reply #18 on: October 10, 2013, 05:14:28 AM »
Bob, Welcome to the Forum.  The cam looks pretty close in your photo.  Maybe move it counter clockwise just a tad as you suggest. 

Offline WesternElectricBen

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Re: 7D Dial Cleaning & Lubrication
« Reply #19 on: October 10, 2013, 05:21:07 PM »
The first pic I gave you is a bad example, look at the last one.

Ben

Offline DrBob

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Re: 7D Dial Cleaning & Lubrication
« Reply #20 on: October 10, 2013, 05:54:47 PM »
I took it counter clockwise to about the 10 o'clock position. Installed in the phone and is dialing correctly.

Thank for the help.
Bob

Offline finkmac

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Re: 7D Dial Cleaning & Lubrication
« Reply #21 on: January 23, 2016, 11:55:53 PM »
Apologies for the necropost, but is there a step-by-step disassembly guide for these 7D dials?

I tried to reposition the cam on mine by disassembly, but couldn't figure out how to get further than removing the screw posts…

Now after moving the cam without completely disassembling it, the finger wheel won't turn the rest of the components anymore!
 It just *click* *click*…
Have I destroyed mine?  :(
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Offline G-Man

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Re: 7D Dial Cleaning & Lubrication
« Reply #22 on: January 24, 2016, 05:15:02 AM »
 Bell Laboratories and Western Electric never intended for 7-type dials to be adjusted in the field. Soon after their introduction, it became apparent that a severe noise problem, caused by the gears meshing, needed to be addressed, as is shown in updated Bell System Practices. Other than these specific instructions, other adjustments were discouraged and field techs were instructed to simply replace the dial.
 
"After dustcover is removed, do not touch dial contacts or governor. These two assemblies are carefully adjusted at the factory. Any distortion will change the percent break in pulsing contacts or speed of governor."
 
However, ITT was far more pragmatic since a larger number of their customers were small independent telephone companies whose owners typically tried to save as much money as possible by attempting to repair even the most trivial pieces of equipment and supplies. They provide very detailed instructions for the disassembly of their clones of Western Electric 7-type dials.
I am attaching portions of Bell System Practice 501-162-100 showing Bell’s perspective and in the next post, I’ll attach ITT’s instructions for the disassembly of their dials.
« Last Edit: January 24, 2016, 07:52:13 AM by G-Man »

Offline G-Man

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Re: 7D Dial Cleaning & Lubrication
« Reply #23 on: January 24, 2016, 05:36:19 AM »
Here are the instructions from ITT for their version of WECo's 7-type dial.
Also, remember Steve Hilsz offers expert dial repair and adjustment if all else fails.

Offline finkmac

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Re: 7D Dial Cleaning & Lubrication
« Reply #24 on: January 25, 2016, 01:27:46 PM »
This page did the trick, thanks a bunch!

Still sounds a bit scratchy, so I'll have to lubricate it and adjust it a bit.
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Offline dlvh

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Re: 7D Dial Cleaning & Lubrication
« Reply #25 on: September 23, 2017, 10:41:58 PM »
This thread is indeed VERY helpful!

Offline finkmac

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Re: 7D Dial Cleaning & Lubrication
« Reply #26 on: October 18, 2017, 11:25:40 PM »
Oh boy another annoyance!

New 7D dial to work on. Disassembled, cleaned, and lubricated following this guide. It's waaaay better than when I got it, and mostly smooth but…

If I turn it slowly I can hear one of the gears making a sort of "prt-prt-prt-prt" noise, which when turning the dial at a normal speed (say dialing a zero) makes a "grrrrrrrrrrrrrt" noise.

Any ideas what's going on here? I'll try to make a video or something to better communicate the noise.
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Offline RotarDad

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Re: 7D Dial Cleaning & Lubrication
« Reply #27 on: October 19, 2017, 02:22:10 AM »
There is just the one adjustment with the oblong hole for one of the geartrain mounting screws.  I've worked on dozens of number 7s.  I think you may be just dealing with 1950s manufacturing tolerances.  Many of these dials are super smooth after servicing, but others seem to remain somewhat gritty no matter the lube or adjustment.

I had one in my '62 565 multiline where I determined the geartrain was just not exactly parallel to the large center gear when installed.  I shimmed the geartrain with a small piece of sheet aluminum, and the dial smoothed out quite a bit.  With WE number 7s, in mid '58 they started using an impact method to flatten tabs on the frame instead of screwing them together.  I think this later design sometimes tweaked the gears out of alignment a bit.  Imho the older ones are often smoother.....
« Last Edit: October 19, 2017, 02:32:56 AM by RotarDad »
Paul