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Snagged my first Mercedes Dial on an AE 21 Candlestick off of eBay

Started by TelePlay, June 27, 2016, 09:37:29 PM

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cloyd

Teleplay,
I understand your attraction to the Mercedes dial.  They are very cool.  8)  Isn't the finger wheel alone worth as much as you paid?  Good luck sleuthing on the receiver material!  :)
Tina
-- I am always doing what I cannot do yet, in order to learn how to do it. - Van Gogh -- 1885

rdelius

That is a WE hard rubber rec shell. the dial is a type 23?.Note holes in the chassis for mounting it and the fingerwheel holes are somewhat larger.

AE_Collector

I think the Type 23 went to a conventional looking AE number card and holder though the card/holder may have been slightly smaller diameter than the more familiar card/holder. Being an early Type 21 stick I  think it possible that it originally came with a Type 18 or a Type 23 dial.

Terry

Jack Ryan

Quote from: rdelius on June 29, 2016, 10:02:44 AM
The dial is a type 23?.Note holes in the chassis for mounting it and the fingerwheel holes are somewhat larger.

Dials made either side of 1923 can be difficult to tell apart but I don't think this finger wheel or the presence of the mounting holes on the rear are definitive evidence of a Type 23 dial. The finger holes were actually enlarged on the Type 18 Mercedes.

This dial looks like a Type 18 because of the finger wheel, number card retainer and the main spring/off normal cam but each can be substituted. The cut of the worm wheel (drive) looks like a Type 23 but that also can be substituted.

One would have to first define a Type 23 dial and then compare the dial with that definition. The most significant differences between the Type 18 Mercedes and the Type 23 are in the governor, its thrust bearing and the worm wheel. Most are hard to see without disassembly but the worm wheel difference is obvious - the Type 23 worm wheel is laminated.

Unfortunately the worm wheel can't be checked in the pictures of this dial; we need a picture about 45 degrees off the axis to see any lamination.

By the way, Type 18 is not the official name for a 1918 model Mercedes dial; I use it for convenience. For that matter, the name Mercedes is not official either. The Mercedes Benz emblem didn't look like a star in a circle until about 1980.

Jack


TelePlay

Quote from: Jack Ryan on June 29, 2016, 12:46:41 PMOne would have to first define a Type 23 dial and then compare the dial with that definition. The most significant differences between the Type 18 Mercedes and the Type 23 are in the governor, its thrust bearing and the worm wheel. Most are hard to see without disassembly but the worm wheel difference is obvious - the Type 23 worm wheel is laminated.

Unfortunately the worm wheel can't be checked in the pictures of this dial; we need a picture about 45 degrees off the axis to see any lamination.

Here's the worm wheel. It is laminated. What is the best angle to get a shot of the governor and excuse my ignorance here, what or which is the thrust bearing?

Being a laminated worm wheel, do that make this a Type 23 or could it be a Type 18 with a 23 worm wheel? A Frankendail or sorts

And, yes, it is a bit oily. The quick cleaning followed by massive oil was to get it to turn free. It would not return even when forcing it a bit. Must have been a lot of built up crud holding it in place. The extra oil softened up whatever was the problem but the dial does need a good cleaning and re-oiling with minimal oil.

Jack Ryan

That's a Type 23 worm wheel.

The thrust bearing is on the end of the governor shaft. A Type 23 dial uses a ball bearing and the Type 18 uses a jewel bearing.

At this point I think it is a hybrid Type 18/23. This may have happened during factory or operating company workshop refurbishment.

Here is a summary of the development of the Type 18 and Type 23 dials by H. F. OBERGFELL, Development Engineer, Automatic Electric Inc. from AT:

Type 18 Dial:
In 1918 further improvements were made. The shunt spring group was separated from the impulse spring group. This was done to avoid the critical adjustments between a shunt spring and its corresponding impulse spring in which the lower shunt spring made contact with the upper impulse spring. The ratchet arrangement of the main gear was also changed, the clock spring was eliminated and a hardened dog held by a phosphor bronze spring was substituted. In addition, the finger holes in the finger plate were enlarged to one-half inch in diameter (the previous holes were 15/32 inch), to permit of more convenient operation of the dial, as well as greater visibility for the numbers.

Type 23 Dial:
Still more improvements were brought about in 1923 the laminated worm wheel and ball-bearing governor were introduced. The earlier models of the small type used a jewel bearing to counteract the thrust of the worm. In order to secure a more uniform type of thrust bearing, and to eliminate the difficulties encountered by soft jewels and uncertainties of jewel bearings in general, the ball-bearing type was substituted. The thrust bearing consisted of a ball race, hardened, highly polished and concaved, and a single very high grade steel ball held loosely in position between the hardened, highly polished end of the worm and the ball race. This type of bearing has been subjected to innumerable tests one of which represented over seven hundred million revolutions, proving it to be the most suitable type of thrust bearing for this purpose.
The design of the governor wings was also altered, phosphor bronze formed in a cup shape being used, and the fly balls made of brass with an insert of fiber. This construction entirely eliminated any abrasive action between the fly balls and the governor cup. The laminated type of worm wheel was substituted for the solid bronze type. This consisted of two bronze discs inclosing a fiber disc. After being cut the worm wheel was subjected to a temperature high enough to exclude moisture, and then treated in oil in order to prevent further absorption of moisture. The laminated worm wheel absolutely prevented sticking between the worm and worm wheel, which was important since a dial is expected to operate satisfactorily for a great number of years without additional lubrication. The main spring was changed to a uniform diameter throughout its entire length, and the lever arm for the shunt springs was altered in order to secure a more positive action, as well as to make it easier to tension the main spring. The escutcheon for mounting the escutcheon cards was improved.


Jack

Jack Ryan

Of course none of this detracts from the fact that you made a very good buy.

Jack

TelePlay

Quote from: Jack Ryan on June 29, 2016, 09:18:23 PM
The thrust bearing is on the end of the governor shaft. A Type 23 dial uses a ball bearing and the Type 18 uses a jewel bearing.

Jack,

Thanks! Informative and making progress on this dial.

Here is the thrust bearing. It looks like a newer AE dial but smaller so I would assume it's a ball bearing thrust bearing. But I don't know, that's why I'm asking - and appreciate your help with this.

TelePlay

A similar receiver photo from eBay. At least I know what cap should go with mine.

unbeldi

Quote from: TelePlay on July 01, 2016, 08:50:55 AM
A similar receiver photo from eBay. At least I know what cap should go with mine.

Are you sure?   That looks awfully like a WECo 144.

poplar1

Quote from: unbeldi on July 01, 2016, 08:52:53 AM
Are you sure?   That looks awfully like a WECo 144.


As Robby already pointed out, John's receiver is Western Electric.
"C'est pas une restauration, c'est une rénovation."--François Martin.

Doug Rose

John....way too long....pictures of your refurb. This will be great!...Doug
Kidphone

TelePlay

Quote from: poplar1 on July 01, 2016, 10:18:16 AM
As Robby already pointed out, John's receiver is Western Electric.

Yes, and that makes sense with the core being WE. The eBay photo was just for comparison of the shell, the mottled look, to mine. The eBay seller did not state or claim a manufacturer of the shell for sale.

Did AE use WE receivers on the AE 21? If so, which one(s).

Thanks for all  help on this project. I've never restored a stick before, one with missing parts, so this is all new to me.

Doug Rose

John....I don't think the AE 21 had a WE receiver.,....does it matter? Get a cap that fits...Oldphoneshop has a really good repro and start from there. This will be a killer phone or as a wise man said " every phone room needs a lamp." Okay...he is not that wise....Doug
Kidphone

AE_Collector

Yes AE had their own receivers. But as I have stated elsewhere, I cant tell one receiver from another in almost all cases, not even AE's from others. It would be great if we could get a receiver comparison topic going with some pictures.....in the "Telephone Component Identification" area.

Terry