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BigMike782
03-22-2019, 10:05 PM
I have a 60s or 70s vintage Pam electric clock that stopped working. I took it apart and found a gear that I believe is some type of fiber that is missing about half its teeth(all other gears in the movement are brass).
I have looked online and facebook but no luck.
I am a hammer and chisel machinist, is there anyone here that might be able to make a new gear?

LKeithR
03-22-2019, 10:34 PM
Did you try Stock Drive Products?

http://www.sdp-si.com/products/Gears/Index.php

BCRider
03-22-2019, 11:37 PM
Give us some dimensions and the number of teeth for the gear. There should be enough of it around one edge or the other to allow measurements of this sort. And while you're at it the length of it and the size of the shaft it has to fit onto.

I know that over the years I've saved all my small gears and I'm sure that there are others in the same boat. One of us might have what you need.

Illinoyance
03-23-2019, 11:00 AM
If you can't find a gear, read this: https://www.amazon.com/Machinists-Publishing-Practical-Inexpensively-Non-Technical/dp/1565239172?SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duckduckgo-ffsb-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=1565239172

Clickspring has a series of You Tube videos on reproducing the Anklyathera(?) machine and is cutting gears with a file.

Zahnrad Kopf
03-23-2019, 12:07 PM
... is there anyone here that might be able to make a new gear?


Depends on what you want to apply to your resources of searching. Once you have exhausted the readily obvious sources and find no love, I'm sure that I can help. But definitely try other avenues first. Even looking on eBay for a replacement clock to steal parts from.

One the larger ones done lately - ( in process, pre-grinding )

https://scontent-ort2-1.cdninstagram.com/vp/38c5b5c44f43b7b90daaa19545ca6aac/5D1B1560/t51.2885-15/e35/51638617_128606884937661_488965396019164594_n.jpg? _nc_ht=scontent-ort2-1.cdninstagram.com

Finished up -

https://scontent-ort2-1.cdninstagram.com/vp/2075697e2b482c4a9087d1fb1b06f2ac/5D2BF631/t51.2885-15/e35/53498345_2287868734800804_7799355902058979722_n.jp g?_nc_ht=scontent-ort2-1.cdninstagram.com

Some from the past -

https://scontent-ort2-1.cdninstagram.com/vp/7aca398b653461abb0d23d93b6eb3a99/5D2F6B3E/t51.2885-15/e35/30829878_165392204145908_435763722540023808_n.jpg? _nc_ht=scontent-ort2-1.cdninstagram.com

https://scontent-ort2-1.cdninstagram.com/vp/22f3d69fa441b5221cfb0e74595b5d91/5D2F213C/t51.2885-15/e35/18722452_1426782924049863_6417507457572012032_n.jp g?_nc_ht=scontent-ort2-1.cdninstagram.com

J Tiers
03-23-2019, 01:01 PM
If it is the type gear I am thinking of from other electric clocks, those gears are huge by comparison.

I'm thinking his gear may be 2 or 3 mm diameter overall.

Zahnrad Kopf
03-23-2019, 01:18 PM
If it is the type gear I am thinking of from other electric clocks, those gears are huge by comparison.
I'm thinking his gear may be 2 or 3 mm diameter overall.


Definitely agreed. Unfortunately, those are just what I had readily at hand. I've made hundreds of gears that small over the years. I just don't have their pictures handy at the moment. :cool: :D

Wait! ... dangit... nope... these are still a little large...

https://scontent-ort2-1.cdninstagram.com/vp/68a6a55a78694d8fd77bdfef1bcf2388/5D0F97F2/t51.2885-15/e35/14591172_356753348020506_4372448789487681536_n.jpg ?_nc_ht=scontent-ort2-1.cdninstagram.com

754
03-23-2019, 03:41 PM
ZAHNRAD, I have a question about the gears in the pic with the quarter
The side by side ones, are they done on the gear shaper ?
I am asking because without a groove at the bottom, I can't see how the chip breaks.
Or are they done with a small endmill ?

mihit
03-23-2019, 03:45 PM
You could try an RC/ model/ hobby shop...

BigMike782
03-23-2019, 03:57 PM
Took some pics today and will try and post this evening from the laptop.
Largest dimension is just over 5/8”....small enough I can barely hold it free hand.

Zahnrad Kopf
03-23-2019, 04:35 PM
ZAHNRAD, I have a question about the gears in the pic with the quarter
The side by side ones, are they done on the gear shaper ?
I am asking because without a groove at the bottom, I can't see how the chip breaks.
Or are they done with a small endmill ?


End mill? From a self admitted GearSnob™️? Heavens no...

No, those were a two piece design.** If you look at some the others in the picture, you can see the other side of them that illustrates the DoubleD feature used to insure against rotation, along with the press fit.

**- Many of the larger, more common, traditional gear shapers don’t deal well with the smaller pitches such as these, due to the correspondingly smaller relief groove, and they also wanted to maintain a certain maximum Face Width. So, other methods are some times employed. As well, those were prototypes for a widget that was headed to market and they wanted to torture test some prototypes but also maintain some economic frugality while doing so...

754
03-23-2019, 04:48 PM
Ahhhh, I had thought maybe pinned .. thanks.
In traditional gear shaping a double gear needs a groove or relief to let chip break, is what I was thimking.

Zahnrad Kopf
03-23-2019, 05:10 PM
Ahhhh, I had thought maybe pinned .. thanks.
In traditional gear shaping a double gear needs a groove or relief to let chip break, is what I was thimking.

No worries. It was clear.
Anecdotally, I’ve done literally thousands of little guys like these, and am a big fan of the DoubleD ( or even Single D shape ) for anti rotation preventative measure. It’s a quick and easy way to do so while still maintaining the quality of the press fit and also avoiding other extra measures. ( like pins, screws, keys, or welds )

JRouche
03-23-2019, 06:46 PM
Anecdotally, I’ve done literally thousands of little guys like these, and am a big fan of the DoubleD ( or even Single D shape )

Its a good joint. My car has the double D for the steering column. Its pinned also. JR

BigMike782
03-23-2019, 08:44 PM
http://i372.photobucket.com/albums/oo170/vwguy3/9FEF2BCC-E566-409B-901C-AE71D32B1260.jpeg (http://s372.photobucket.com/user/vwguy3/media/9FEF2BCC-E566-409B-901C-AE71D32B1260.jpeg.html)
http://i372.photobucket.com/albums/oo170/vwguy3/690D2250-0946-41BE-8F52-C2D0CC061AF5.jpeg (http://s372.photobucket.com/user/vwguy3/media/690D2250-0946-41BE-8F52-C2D0CC061AF5.jpeg.html)
http://i372.photobucket.com/albums/oo170/vwguy3/8AAA42C8-F471-44BA-A093-ED8C81AE9EA3.jpeg (http://s372.photobucket.com/user/vwguy3/media/8AAA42C8-F471-44BA-A093-ED8C81AE9EA3.jpeg.html)
http://i372.photobucket.com/albums/oo170/vwguy3/FCD401D7-1E3D-4D05-B8DE-F2324B134A94.jpeg (http://s372.photobucket.com/user/vwguy3/media/FCD401D7-1E3D-4D05-B8DE-F2324B134A94.jpeg.html)

BigMike782
03-23-2019, 08:50 PM
Wow!.....I had forgotten what a PITA photobucket is.
Well, hopefully I got all the pertinent information.

Zahnrad Kopf
03-23-2019, 09:02 PM
You are also going to want the Center Distances of them and their mates.

BigMike782
03-23-2019, 09:32 PM
Clarify please.

PStechPaul
03-23-2019, 11:42 PM
I tried using the gear size calculator (https://www.technobotsonline.com/gear-size-calculator.html) to determine what the gear might be.

If the overall diameter of the 68 tooth gear is actually 17.5 mm (0.690"), it is 0.25 module metric.

If actually 17.75 mm (0.700"), it is 100 DP.

14.82 mm (0.584") would be 120 DP.

If it is 0.630" as you measured, that is 16 mm, and would be 0.23 MOD or 111 DP.

The small 9 tooth gear 0.119" OD is 3.0 mm which would be 0.27 MOD or 93 DP.

If it's actually 2.94 mm (0.116") it would be a standard 96 DP.

The ratio is 7.555 or 0.132.

You might try buying a few bags of small "Steam Punk" gears. Maybe you'll get lucky.

https://www.aliexpress.com/w/wholesale-steampunk-gears.html

https://ae01.alicdn.com/kf/HLB1VBf.bfjsK1Rjy1Xaq6zispXaz/10g-bag-Steampunk-Gears-Vintage-Steampunk-Wrist-Watch-Old-Parts-Gears-Wheels-Steam-Punk-Lots-DIY.jpg_220x220xz.jpg https://ae01.alicdn.com/kf/HTB1H2nHGWSWBuNjSsrbq6y0mVXaA/42Pcs-Pack-Mix-Alloy-Mechanical-Steampunk-Cogs-Gears-DIY-Pendant-Jewelry-Craft.jpg_220x220xz.jpg

Noitoen
03-24-2019, 03:54 AM
That should not be so complicated to make. I would keep the small gear, clean the damaged one to a little smaller diameter, cut and solder a donut ring and cut new teeth.

It would be much more difficult for me to do the small one.

Alan Smith
03-24-2019, 04:37 AM
The small gear (pinion) you would normally buy from a clock/watchmaker supplier a length of pinion wire which is the gear profile extruded/drawn in brass or steel.

BigMike782
03-24-2019, 12:23 PM
Not sure if this helps but....
Gear that drives is 8 teeth and .110 od

RWO
03-24-2019, 01:35 PM
Check this thread: https://mb.nawcc.org/threads/pam-clock-motor.149743/ Scroll down to #5

RWO

Orrin
03-26-2019, 01:22 PM
That should not be so complicated to make. I would keep the small gear, clean the damaged one to a little smaller diameter, cut and solder a donut ring and cut new teeth.

Snip

That is a good suggestion. I've done something similar, except I found a gear in my junk box that was the same diameter with the same number of teeth. I bored one and turned the the ruined fiber one to fit. A bit of creative J-B Welding bonded the two for life.

Years later it is still doing well.