Author Topic: 7D Dial Cleaning & Lubrication  (Read 13914 times)

Offline Dennis Markham

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7D Dial Cleaning & Lubrication
« on: November 13, 2008, 08:04:05 PM »
When I come across a dial that is just so gummed up it has to be cleaned, I do the number on it.  I completely disassemble the dial, clean the parts, reassemble and lubricate at the axle points.  I do this with #6 Dials, 7A, 7C and 7D dials.  However later 7D dials that are assembled with crimped ends, rather than screws, I don't disassemble them completely.

In the following photos I'll show an example of a dial that was over lubricated.  The lubrication became thick gel, slowing the action of the dial.

The cleaning can take place without disassembling, but I particularly enjoy tearing it apart to clean it.  I taught myself by doing just that.

I first spray the dial parts with the Electrical Contact Cleaner that I mentioned in another posting.  I purchase that cleaner from Radio Shack.  A 6 oz can is about $10.  They have two, one with a lubricant and one without.  Use the one WITHOUT lubricant.   After spraying the parts I use a cloth and compressed air to remove the grunge.

I then use a tooth brush to clean the gears.  Once the gears are completely dry I use a Dremmel tool with the small steel wheel to clean between each tooth of the gears.  I do this under one of those lighted bench magnifying glasses.  That also helps to protect my eyes from steel bristles that may and WILL fling away from the wheel.  Use safety glasses.  Those things are nasty and you don't want to get one in your eye(s).

Once the gears are clean I use Simichrome polish to clean the metal surfaces.  No one will ever see your dial gears but that's not the point with me.  I like knowing they are clean and will be for a long time.  They will work just fine with no shine on them....just remove all that old gum and lint.

Once the parts are clean I reassemble the dial.  The dial may screech after reassembly.  It will get quieter once the contact point assembly is put back on the dial.  Also, after point oiling it will get quiet---and even quieter once the dust cover is replaced.

In addition to cleaning the gears I also use the wire wheel on each of the 4 spade tips that connect the dial to the network block.  There are two white (slate), one green and one blue.   I use a fresh Q-tip and some alcohol and clean the pulse contact tips.  I use compressed air to then blow away excess moisture and cotton fibers--if any.  I also remove the plastic cam that pushes the contacts together when the dial is at rest.  Be careful if you remove this. There are two very thin small pieces of brass---washers that are under the cam and associated plastic part.

I put oil on the axle tips where they come through the framework.  With the drop of oil sitting on the axles I turn the dial to allow oil to seep around the axle.  I then take a fresh Q-tip and absorb all excess oil.  You don't want a bunch of oil flying around as the dial spins.  You especially don't want it to get between the pulse contacts.  Turning the dial upside down, I place a drop of oil below where the governor is attached to the brass frame.  Again, I remove excess oil.  So you are oiling all places where movement on axles occurs.  

This is a general run-down of the work that I do.  It is more involved as far as removing the main gear nut and the spring unwinding.  The rewinding of the spring takes two turns to make the proper tension.  If the dial isn't returning properly with two turns of the spring it is more than likely a result of the gear mesh not being adjusted properly.

If anyone has questions or would like more information just let me know.

I also do similar work on #4 and #5 dials but didn't mention them here because of the differences in the dials mentioned here.
« Last Edit: October 26, 2010, 09:29:11 PM by Dennis Markham »

Offline McHeath

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Re: 7D Dial Cleaning & Lubrication
« Reply #1 on: November 13, 2008, 10:42:42 PM »
I've never pulled a dial apart yet, it makes me nervous to think about screwing it up.  And if it can be screwed up I will manage it, don't even ask about the number of times I've let little parts shoot off into space by a slip of the finger when part A was being pushed down against spring B.   My parts phone has a 9 series dial that I've been thinking about pulling apart and seeing what happens, I'm sure it won't be pretty.

That electrical contact cleaner from Radio Shack is good stuff, I used it around the house on the intercom system to clean up the connections and it sure made a difference.



Offline Dennis Markham

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Re: 7D Dial Cleaning & Lubrication
« Reply #2 on: November 13, 2008, 10:51:51 PM »
I pulled a #9 apart once...never got it back together.  The spring unwound and that was that.  I made the mistake of loosening the little nut in the center of the dial.  However, that was some time ago and I've learned more since then.  Although I have picked up a handful of phones with #8 and #9 dials in the past, I try and stay with older phones.  They're easier to work on.....for me.  The Princess phones have the later dials.

Offline McHeath

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Re: 7D Dial Cleaning & Lubrication
« Reply #3 on: November 13, 2008, 10:59:49 PM »
There you go, if you could not get the spring back on the number 9 dial, I certainly won't be able to!  It does generally seem to be true that the older the phone the simpler it's made and easier to work on.  It kinda amuses me every so often to think about how we are putzing around in these old Bell System Property phones, doing stuff that only the high trained techies were allowed to do back in the old days.  Mark even has a nice manual online to read for the Kellogg K-500 so that we can see all the inner secrets once known only to the initiated. 

Offline JorgeAmely

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Re: 7D Dial Cleaning & Lubrication
« Reply #4 on: March 30, 2010, 12:04:24 AM »
McHeath:

Do you know where that document is?
Jorge

Offline McHeath

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Re: 7D Dial Cleaning & Lubrication
« Reply #5 on: March 30, 2010, 12:08:05 AM »

Offline Phonesrfun

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Re: 7D Dial Cleaning & Lubrication
« Reply #6 on: March 30, 2010, 12:12:23 AM »
Here's one on AE dials if you haven't seen this one already:

-Bill G

Offline Jim S.

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Re: 7D Dial Cleaning & Lubrication
« Reply #7 on: March 30, 2010, 03:23:04 AM »
I've never pulled a dial apart yet, it makes me nervous to think about screwing it up.  And if it can be screwed up I will manage it, don't even ask about the number of times I've let little parts shoot off into space by a slip of the finger when part A was being pushed down against spring B.   My parts phone has a 9 series dial that I've been thinking about pulling apart and seeing what happens, I'm sure it won't be pretty.

That electrical contact cleaner from Radio Shack is good stuff, I used it around the house on the intercom system to clean up the connections and it sure made a difference.




Paul wiltfong told me he  modified a sandblasting cabinet when he decided to disassemble a schmoo dial. He said the parts went everywhere. He was able to get it all back together and working. He also had online photos of the procedure at one time.
Jim
You live, You learn,
You die, you forget it all.

Offline Kenny C

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Re: 7D Dial Cleaning & Lubrication
« Reply #8 on: March 30, 2010, 01:40:44 PM »
I pulled a #9 apart once...never got it back together.  The spring unwound and that was that.  I made the mistake of loosening the little nut in the center of the dial.  However, that was some time ago and I've learned more since then.  Although I have picked up a handful of phones with #8 and #9 dials in the past, I try and stay with older phones.  They're easier to work on.....for me.  The Princess phones have the later dials.

I did the same thing and I will never pull one apart again.
In memory of
  Marie B.
1926-2010

Offline JorgeAmely

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Re: 7D Dial Cleaning & Lubrication
« Reply #9 on: March 30, 2010, 02:15:02 PM »
Kenny:

It is not that difficult to put it back together. Just store about one or two turns of tension on the spring before you put the screw back on again.

Jorge

Offline Babybearjs

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Re: 7D Dial Cleaning & Lubrication
« Reply #10 on: May 29, 2011, 04:44:57 PM »
Dennis, I picked up some silicone spray and used it on a AE 24 dial. at first, I thought it did'nt work because the unit was still sticky. then about 10 minutes later, the dial started working fine... is silicone spay good to use, or is watch oil better? I normally have used WD-40 for everything and this is the first time I used silicone. what doe the "experts" recommend??  John
John

Offline Ed D

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Re: 7D Dial Cleaning & Lubrication
« Reply #11 on: May 31, 2011, 12:18:25 AM »
John, I'm no expert, but I'd say that the silicone spray dissolved and lubed the dial so it worked freely.  However, as I understand it, using such a technique is a big no-no for phone dials.  And silicone spray is probably not a good choice for dial lube.

** Hey guys, let me know if I'm off base here - I'm trying to learn, and willing to share what I know.  But if I'm wrong, please say so. **

Don't use WD-40 as it can dry out and get gummy.  Use watch oil, or a good light oil like "3-In-1 Oil".

One place you don't want to lubricate on a dial is the governor, and spraying any lube on a dial can cause it to get in there if you are not careful.

Then there is the issue of over-oiling the right places.  The excess oil catches dust to gum up the works again.  Plus if the lube dries out, there is even more gummy stuff to gunk-up the works again.

I found this link to an article here on dial lube jobs:
http://www.classicrotaryphones.com/forum/index.php?topic=285.msg2467#msg2467

One day I will venture into dial repair - I have several junky phone dials that I can practice with.

Ed


Offline twocvbloke

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Re: 7D Dial Cleaning & Lubrication
« Reply #12 on: January 30, 2012, 04:33:58 AM »
Just thought I'd add that this thread helped me get my red Tenite WE500's 7C dial all cleaned, lubricated and set up, so it's even quieter than it was before, it's faster and pulsing at the right rate (and the right count, managed to put the cam on the wrong way initially, and it was dialling 11 pulsed on a 0!!), so I'm pleased... ;D

I was going to tackle the gears on the 7D in my black 500, but it's one of them that's got the crimped ends rather than screws on the spacers, so wouldn't be as easy... :-\

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Re: 7D Dial Cleaning & Lubrication
« Reply #13 on: March 28, 2013, 08:47:01 PM »
hi dennis, you must have the patients of a saint to be able to work on all those dials. i only have ever been successful with one dial assemnbly(i believe it was a 7-d)lubrication,and recoiul spring adjustment. dial assemblies and i DO NOT  ;D get along very well. however i will try another one day and nail it. practice makes perfect

Offline DrBob

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Re: 7D Dial Cleaning & Lubrication
« Reply #14 on: October 09, 2013, 09:52:25 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?