200 Series Dial

[PaulR]

I have two bakelite telephones, 200 and 300 series. They both work ok, but the dial on the 200 one is rather sluggish compared with the 300. I haven't done anything to it as I believe that the correct return speed is important. It it OK simply to lubricate the moving parts, and is there anywhere that I should avoid oiling? For example I see that there is a speed governor on it which may react badly to oil.

If oiling isn't the answer is there anything else I can do/adjust to free it up a little?

Thanks

Paul

[russell_w_b]

Originally Posted by PaulR

I have two bakelite telephones, 200 and 300 series. They both work ok, but the dial on the 200 one is rather sluggish compared with the 300. I haven't done anything to it as I believe that the correct return speed is important. It it OK simply to lubricate the moving parts, and is there anywhere that I should avoid oiling? For example I see that there is a speed governor on it which may react badly to oil.

If oiling isn't the answer is there anything else I can do/adjust to free it up a little?

Thanks

Paul

Is it a slipping-cam dial or a pulse-wheel dial?

The cup on the governor may have got full of grime, as might the pin-end brass governor support around the periphery of the dial. This can be adjusted with a screwdriver.

I have had success with dials before by removing all non-metallic parts and boiling the mechanism in water for ten minutes or so; the agitation removes all the grime. Lubricate immediately following this (rather drastic) cleaning action!

It might be better to use something like inhibited solvent or carbon tetrachloride and a brush for a thorough de-greasing. Again, lubricate strategically with light machine-oil. Don't forget the steel coiled-spring under the brass cover, or it will go rusty.

[PaulR]

Many thanks Russell. It sounds a bit like cleaning a clock! I will give it a try.

Regards

Paul

[Nickthedentist]

Hi Paul,

Here's the totally un-approved way I did it...

Remove the governor "cup" and bearing, followed by the governor/worm assembly itself. Check that the dial then works freely, albeit with no speed control [don't let the dial snap back all the way home without restraint though, obviously].

If all's basically ok, clean the bearings at either end of the governor assembly (both the male and female bits), lubricate them with clock oil and reassemble.

The governor "cup" and "pads" are meant to be dry, but just the lightest smear of clock oil seems to do no harm.

Then, USE IT. I find they often free up naturally after a few days of use.

Nick.

PS Apologies to Mike Phelan and the other clock/mecahnical experts for using all the wrong terms

[Broomradioman]

be careful with Carbon Tetrachchloride and it is severely nasty stuff and has a fearsome reputation as a carcinogen (cancer causer!). I personally love the smell but is not v good for you.!!

Jim BRM

[russell_w_b]

Originally Posted by Broomradioman

be careful with Carbon Tetrachchloride and it is severely nasty stuff and has a fearsome reputation as a carcinogen (cancer causer!). I personally love the smell but is not v good for you.!!

Indeed... It goes without saying that you must follow all COSHH instructions, work in a well-ventilated area, and wear appropriate PPE before embarking on a course of chemical degreasing, should such action be necessary!

You may find carbon tet. hard to obtain these days; it is thirty years since I used it for anything. 'Colclene' or other 'inhibisol' replacements will be safer.

I rather like Nick's idea of starting with the governor and seeing if the rest of the dial is OK first. He is certainly correct about useage, as they do stick somewhat if not used often.

[PaulR]

Thanks all,

I will use dismantle it and give it a clean and oiling. I was concerned that there may be some parts I shouldn't oil but it seems OK to follow common sense.


Cheers

Paul

[russell_w_b]

Originally Posted by PaulR

Thanks all,

I will use dismantle it and give it a clean and oiling. I was concerned that there may be some parts I shouldn't oil but it seems OK to follow common sense.

There's an interesting article by Andrew Emmerson in the Telecommunications Heritage Journal about the use (or not!) of WD40. Andrew outlines several valid reasons why this stuff should NOT be used to clean electical equipment.

He suggests - for telephone dials - the use of normal white spirit (turps substitute), soaking for ten minutes before draining off, cleaning with an old toothbrush, and leaving to dry on paper kitchen towel.

[BakeliteBear]

I have serviced dozens of dials and would not soaking the dial in anything at all unless I was going to fully strip it down (see below) and then a quich soak in hot soapy water followed by a spray of WD40. It is usually only necessary to clean and lubricate the speed governor. DO NOT lubricate the inside of the cup! It will collect dust and muck, which will, eventually, gum up the works. In this case, oiling is a short term ‘fix’ which will not work long term. The best idea is to remove the cup and polish the inside with Brasso and also the brass paddles on the rotating arm. Careful reassembly and realignment will then get it to run smoothly. I remove any other muck with a toothbrush.

If the dial spring is broken or the main shaft is dry then I fully disassemble the dial to its component parts – not really a job for a beginner or the fainthearted! This is rarely necessary, but I end up doing this in about 5% of the dials I work on. Take plenty of pictures as you go. Good Luck.

[Majicou]

Originally Posted by russell_w_b

There's an interesting article by Andrew Emmerson in the Telecommunications Heritage Journal about the use (or not!) of WD40. Andrew outlines several valid reasons why this stuff should NOT be used to clean electical equipment.

He suggests - for telephone dials - the use of normal white spirit (turps substitute), soaking for ten minutes before draining off, cleaning with an old toothbrush, and leaving to dry on paper kitchen towel.

I repair dials on a frequent basis and know Andy Emmerson. White spirit and sewing machine oil is the best way to go. WD40 will only ever cause it to gum up again and water will cause rust. The EI for these dials is available and I can send you a copy off group if you need one, that explains exactly where to lubricate. I would not recommend removing the govenor cup as it is set accuratly and is almost impossible to set correctly again

Cheers

Andy

[PaulR]

Thanks for the information. I used a very little clock oil on the pivots, and that seemed to do the trick. It wasn't very sluggish, just a little more so then my 300 series. The 300 lives in my office and gets used several times every day which might also account for the difference.


Paul

[BakeliteBear]

To clarify what I said previously:

I never soak an assembled dial in water. But for fully stripped parts with filthy ingrained grime come clean in hot soapy water in a matter of seconds and a quick rinse in clean hot water, and followed by 15mins on a hot radiator does no harm at all. My best telephones have had this treatment and show no signs of corrosion after 10+ years.

I agree fully, that random spraying of WD40 on an assembled dial does no good at all, but a quick spray on disassembled parts followed by a good wipe with kitchen roll adds a protective layer without leaving a sticky residue.

As to removing and removing the govenour cup for cleaning; it really depends how thorough you want to be, and reassembly does require a degree of skill. There is often a good deal of gunk in the cup, which I like to get rid of, and polishing the surfaces reduces significantly future build up.

If everything is properly cleaned and lubricated then speed can be finely adjusted by adjusting the arms on the speed governing arms, but I have worked on many dials, especially European ones, where these arms have been bent into horrid shapes in an attempt to compensate for slow speed rather than what the dial actually needs, which is a full and thorough service.