AE Type 24 Dial Assembly

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This topic will cover the assembly of an AE Type 24 dial including proper lubrication.

This topic assumes the dial has been completely disassembled and all parts cleaned.



These are the parts that will be assembled in this topic.

First step is to attach the governor raceway.



The inside center of the raceway has a small hole which is the bearing point for the governor fly wing axle end. A small amount of clock oil is placed in this hole. No other part of the raceway is to be lubricated, the raceway or the shaft fly wings.



Once the oil is applied, the raceway is mounting into the dial case and secured with the nut and a 1/4" wrench.



Next step is to carefully insert the governor shaft through the dial case (red line).

The fly wing end of the shaft is inserted into the small hole in the raceway cup.



A small amount of clock oil is applied to the opening in the set screw and the end of the governor shaft (blue circles). The set screw is then screwed into the dial case making sure the end of the shaft is centered in the set screw and the fly wing end of the shaft stays in the bearing point in the raceway.

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Making sure the flywing end of the shaft stays in the bearing point inside the raceway, use a slotted screw driver to screw in the set screw (green arrow - helps to have the lock nut backed all the way out at this point). Slowly tighten the set screw until the governor shaft no longer turns freely.

At that point, back out the set screw one complete turn. Use a 1/4" wrench to tighten down the lock nut (red box) using the slotted screw driven in the set screw slot to keep the set screw from turning when tightening the set screw lock. If done correctly the governor shaft will turn freely and will free wheel a bit when spun by hand.



Place a small amount of clock oil on the thrust washer (blue box) on the pulse shaft and insert the shaft from the front side of the dial into and through the dial case (red line).



Place the retaining nut on the threaded shaft (with the serrated side up) and tighten it down.



Turn the dial case over to mount the mainspring gear. Place a small amount of oil on the pulse shaft gear (blue circle). Place a small amount of clock grease on dial case around the main spring tunnel and the outside of the tunnel itself (blue circle).

Place the white fiber washer on the main spring tunnel (red line).

Place a small amount of clock grease inside the main spring gear (inner blue circle) and place a small amount of clock oil on the main spring gear teeth (outer blue circle).

Place the main spring gear (ratchet side up) on the main spring tunnel (red line) making sure the gear meshes with the pulse shaft gear.



Place a small amount of clock oil on the end of the pulsing shaft (blue circle). Place the finger stop into the case making sure the shaft bearing point is on top of the end of the pulsing shaft (red line).

Attach the finger stop to the dial case using the two sets of screws and nuts (the slotted screw heads are inside the dial case, the nuts on the flat pile up side).



Assemble the dial main spring shaft assembly by first putting a small amount of clock grease on the base of the shaft, place the thrust washer on top of that lubrication. Then place clock grease on the base of the main spring shaft, the part of the shaft that will go inside of the main spring tunnel.

Place the winged metal piece on the shaft with the bent tab facing away from the end of the slotted shaft. Place a small amount of clock oil on the metal piece and place the fiber washer on top of it.

Place a small amount of clock oil on the fiber disk.

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Slide the slotted main spring shaft into the main spring gear tunnel.



This side view shows the correct assembly (red circle), the spring loaded ratchet arm (yellow circle) is pulled away from the main spring gear so that it meshes with the ratchet gear on the main spring gear.

NOTE: The ratchet arm is easily disengaged from the ratchet gear until the mainspring is installed. Any slight movement of the slotted shaft out of the tunnel will cause the ratchet arm to disengage. If so, simply pull the spring arm away from the gear and press the assembly back in (toward the case) until the ratchet arm properly engages. Even when attempting to install the main spring, the force downward to install the spring can push the shaft in disengaging the ratchet. When installing the mainspring, it is very important to keep the assembly from moving with strong pressure on the assembly with the palm of the hand.



Make sure the main spring shaft assembly is at the dial stop (red circle) and the ratchet arm is engaged (green circle).



To install the mainspring turn the dial case over holding the mainspring assemble against the mainspring gear.

The mainspring is slid over the mainspring shaft. The bottom spring ear is placed behind the retention wing noted during disassembly (blue line).

The slot in the end of the main spring shaft is as it was before disassembly (with the dial assembly against the dial stop) (red line). The upper spring retention wire, indicated by the green line, is roughly a little more than 1/4 turn away from the slot. As such the mainspring will be installed with between 1 1/4 and 1 1/2 turns of pretension, tension in the spring when the dial is at rest.

Installed that way, the upper wing on the mainspring will be pointing toward the governor shaft (white line). This is the correct position to operate the pulse  and muting leaves of the pile up.

It takes a bit of skill to push down and turn the main spring to get 1 1/4 turns and lock the top retention wire into the slot. Won't be easy the first time, the ratchet may have to be reset, or the first few times. During this trial and error assembly, you will learn to keep the dial tight against your palm, keep the dial mechanism against the dial stop and mount the spring.



With the spring correctly mounted, the top spring retention wire will be the same as it was before disassembly, the upper mainspring wing is in line to mate with the pulsing pileup leaves and the lower mainspring wing is in line to mate with the mute pileup leaves (white lines).



Next step is to mount the red phenolic oblong pulsing disk. The disk is placed on the pulsing shaft with the two holes in the disk lined up toward the center of the mainspring shaft (green line). The small lock washer is placed over the shaft and the top nut screwed down making sure the green line alignment remains in place.

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After the pulsing disk is installed, aligned as shown by the green line, a small amount of clock oil is placed on the governor shaft worms drive and the teeth of the worm gear on the pulsing shaft (blue circles). After oiling, the mechanism can be operated by turning the dial assembly on the finger stop side to distribute the oil evenly.



Next step is to lower the pileup leaves. Loosen the red screws a bit and lower the leaves down making sure they clear the main spring wings, don't get bent. Lower them so that the pulsing mainspring wing (yellow circle) mates with the contact point on the pulse leaves and the muting mainspring wing mates with the mute circuit contact point (green circle).

Place the missing screws through the pile up (will have to align the brown insulator wafers and the insulator tubes inside the pile up so the screws will fit through to the threaded dial case.

Once these screws are started in the dial case mount, the leaves are adjusted so they both line up with each other and mate with the mainspring wings. One can look at the leaves sideways and into the open ends to align the leaves correctly. Once aligned, the screws are tightened down.



The pileup side of the dial is now completely assembled. Turn the dial case over and place the number plate on the dial case. The notch in the number plate (red line) goes around the finger stop. The spring tabs (green circles) used to hold the number plate on the case will be under the number plate but accessible with a good tool to pull them up, out and over the number plate.



This shows the number plate retention tabs in place (green circles).

The finger wheel is mounted on the dial assembly with the holes in the finger wheel aligned with the numbers on the plate.

The number card retention wing (blue line) is placed on the finger wheel so that the wing is between the two stops (red circles).



The center screw is installed to hold the number plate to the dial assembly, and with the card retention wing moving freely.



The number card holder in installed by placing the outward tab (bottom yellow line) into the slot in the finger wheel and the card holder pushed down tight against the finger wheel (upper yellow line). A small, thin flat bladed screw driver is then use to slip under the number card and move the retention tab upward (red arrow)to engage the retention tab facing inward on the number card holder.

The number card holder is not hard to remove but a bit tricky. This link will take you to the TCI library page showing the AE Co. instructions for card holder removal, and attachment.

This card holder information at that link is attached to the next page of this topic as a PDF file.

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That completes the dial assembly. Only thing remaining is to test or determine the dial speed and adjust the governor accordingly to, if needed, get the dial into specifications (8-11 PPS).

If the dial was slow due to crud build up and a field technician tried to increase the speed by adjusting the fly wings on the governor shaft, there is a very good chance that the cleaned and properly lubricated dial will run fast. Field adjustment has taken place when the fly wings of the governor show they were bent.

With practice, assembling a dial with proper lubrication takes about 15 minutes. There are a lot of words above to make sure hopefully all details were covered but in actual practice, the assembly moves along quite quickly.

Any questions, or found errors in everything above, will be appreciated.

[countryman]

Thanks a lot for the detailed description and photographs. I will help me and others a lot in the process of repairing this very common type of dial!
Hopefully I will find the time to carefully follow the steps in the next future.
In many cases I gut by with flushing the dial with brake cleaner and oiling the moving parts. This time some more effort will be required. I've done it with Siemens & Halske dials but the AE construction is quite different.

[Contempra]

Thanks you very much for the detailed description and photographs . No, we'll know how to do it

[TelePlay]

Thanks a lot for the detailed description and photographs.

The disassembly and assembly instruction were detailed to cover all one needs to know to learn how to take an AE Type 24 dial apart, clean it and put it back together with proper lubrication.

Without the detail and images, these are the steps (after doing one or two dials, this is all that is needed by one to restore/clean a dial):

First is DISASSEMBLY:

1 ) Remove finger wheel
2 ) Raise up the pulsing and muting leaves (the pile up)
3 ) Remove the red phenolic pulse disk
4 ) Remove the mainspring
5 ) Remove the main spring shaft assembly and take the 4 pieces apart
6 ) Remove the finger stop
7 ) Remove the main spring gear and washer
8 ) Remove the pulse dialing shaft
9 ) Remove the governor

Next, clean the parts

Then ASSEMBLE with proper lubrication

1 ) Install the governor
2 ) Install the pulse dialing shaft
3 ) Install the main spring gear
4 ) Install the finger stop
5 ) Put the main spring shaft assembly together and insert it into the main spring tunnel
6 ) Install the mainspring
7 ) Install the red phenolic pulse disk
8 ) Lower and align the pulsing and muting leaves (the pile up)
9 ) Install the finger wheel

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Attached to this reply are 2 AE documents discussing the Type 24 "quiet" version dial:

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In many cases I get by with flushing the dial with brake cleaner and oiling the moving parts.

I hadn't done this before, just tried a few different solvents when starting to work on dial and back then found Lacquer Thinner worked best at removing dial crud.

I looked up the composition of 4 solvents that could be used for cleaning dials: 1) Brake Cleaner; 2) Mineral Spirits; 3) White Spirit; and 4) Lacquer Thinner. They are similar but have their own specific differences in make up, composition.

1) BRAKE CLEANER

Acetone 50-60%,
Methyl Alcohol 20-30% and
Toluene 20-30%


2) MINERAL SPIRITS

Petroleum distillates, hydrotreated light,
Alkanes, and
Naphtha (petroleum)


3) WHITE SPIRIT

Hydrocarbons (C9-C12) consisting of:
  N-alkanes,
  Isoalkanes,
  Cyclics,
  Aromatics (2-25%


4) LACQUER THINNER

Aromatic hydrocarbons 30-75%,
Mixture of Ketones 0-60%,
Mixture of Aliphatic hydrocarbons 0-60%,
Mixture of Acetates 0-17%
Ethyl 3-ethoxypropanoate 0-17%
Alcohols, (C1-C3 or methyl, ethyl and isopropyl) 0-12%

Brake Cleaner is similar to Lacquer Thinner and both are quite capable of dissolving oil based crud found on a dirty dial.

Mineral and White Spirits are similar and less aggressive in solvent nature at removing dial crud. They do not contain the more aggressive polar ketones found in Brake Cleaner and Lacquer Thinner.

Any of the four would work but Brake Cleaner and Lacquer Thinner would work better, faster. The spirits would need more scrubbing and cleaning action to remove all crud.

Lacquer Thinner, having 6 different solvents in its mixture verses 3 for Brake Cleaner, would or might work better, in general, than Brake Cleaner in those cases where the three Brake Cleaner components might not dissolve the crud on a specific dial, but one of the extra 3 in Lacquer Thinner might do so.

Also, both contain C1 to C3 alcohols which are there to dissolve water soluble crud.

The big difference is that Lacquer Thinner has aromatic and straight chain hydrocarbons along with polar ketones. Brake Cleaner only has the ketones. That would make Lacquer Thinner a more universal solvent.

[countryman]

I use brake cleaner because it comes in handy pressure packs, and evaporates quickly and virtually odourless. Lacquer thinner evaporates slower and may soak into very hard crud better. The composition of both may vary, the lacquer thinner I usually get would need some hours to evaporate to a point where it becomes odourless.
I normally spray the parts with cleaner and then GENTLY use compressed air to blow away the dissolved crud. Luckily, I did not damage a dial with this method so far. I'm thinking of the solvent being too hard on stamps or the print on the number ring, etc, or blowing away small springs (nightmare).

The AE type dial I'm working on now was full of what looked like lint or short textile fibres. They were wound around the small bevel gear, which twisted them just like a spinning wheel. I cleaned it from the outside using a small brush, a needle and tweezers, but fibres may have got inside the bearing itself. Complete disassembly will be required. Waiting for a quiet day to do this...

[HarrySmith]

I also use brake cleaner. The newer stuff does not leave a residue. I used canned air to blow it out after brushing with a toothbrush. It is also cheaper since I get the brake cleaner from work

[TelePlay]

My comparison of solvents was meant for cleaning individual parts once the dial has been completely disassembled. I put 50 ml of thinner in a glass jar and clean one part at a time, blowing each part off with compressed air after cleaning. The disk case, finger wheel and number plate are cleaned with soapy water, blown dry with compressed air and then heated slightly with a hair dryer to get the water off.

Before I started to take dials apart, I used Radio Shack contact cleaner (the type without lubricant added) and then compressed air to dry the dial. That was a chlorinated hydrocarbon in a can and while being a very good solvent, that chemical (TCE - trichloroethylene IIRC) has been banned from commercial sale.

Cleaning individual parts is a much better way to so it.

With respect to that lint built up dial, it will be interesting to see what's under the number plate - take step by step part pictures before (they also help with re-assembly) and after. I bet your sticking at start problem is build up around the mainspring gear.

[TelePlay]

countryman, if you don't have time to do a complete disassembly, you could just open up the front to get to the gear and ratchet assembly.

Simply remove the finger wheel and then release the 2 clips holding the number plate to the dial case.

You might be able to remove the lint collected there and use the brake cleaner if needed.

The only thing you would need to lubricate after that would be the mainspring gear teeth and flat surfaces of the parts (drop of oil on the edge of them so it can seep in).

[countryman]

Today I found the time to work on the dial. As supposed in your last post, I removed the number plate first. More dirt/lint was found there. Also, the small pulse gear was still impeded by material wound around the shaft. I removed the contact stack, the main spring, the bracket with the finger stop, the ratcheting mechanism and the larger gear. That all came apart straightforward and trouble free. Likewise, it went back together after cleaning.
I now just used soapy water and an old toothbrush to clean. My earlier operations with brake cleaner had degreased the parts so that water was efficient enough. Drying out was no problem with everything disassembled. I also removed the worm gear with the governor, cleaned and straightened the springs. I lubricated the dial as suggested. The main spring tension had to be increased by 1/3 turn, the finger force now feels just right, too.
After adjusting the position of the pulse cam I connected the phone to my "Gossen" dial tester. The speed was OK, but the pulse ratio was out of spec with the break time too long. My VOIP equipment won't accept any  break pulse exceeding 60 milliseconds. Having the dial speed a tad on the high side helps with this problem, but the make/break ratio is as important. I bent the tab that backs up the pulse contact away from the cam by a small amount (diminishing the contact clearance) and everything was fine. I can now dial long numbers trouble free.
Thanks a lot again for the detailed description!
In summary, this repair confirmed for me that this relatively early dial design is superior to many later concepts. Not only it is repair friendly (as I now learned), it "almost" worked in a condition where others would long have completely failed!
I'll look after some other dials of this design in my collection, like some French and Belgian models. I was hesitant of disassembling them after I could make them work "somehow" by cursory cleaning. Until now, I was unsure how to remove the number plate, the main spring and how to adjust the pulse cam. With your help, I now found all these points pretty straightforward.

Pictures:
1 number plate removed
2 ratcheting mechanism and main spring
3 gear shaft impeded by dirt
4 worm gear
5 measuring make/break ratio (J)
6 measuring dial speed (Hz)

[countryman]

This is the situation inside the phone now with the dial cleaned and the modification from the other thread fitted. I used a home made mounting cord. Sorry for the scotchlok connector