Seth Thomas Electric Mantle Clock Fiberglass Transmission Wheel

mproulx

Registered User
Jul 8, 2009
26
0
1
65
Montreal, Canada
Country
Region
Hello,

I have a Seth Thomas model Portsmouth with the popular A300-100 series electric motor. My issue is with the sort of brownish fiberglass type transmission wheel connecting to the electic motor pinion. It has 2 broken theeth (see the attached picture) and was wondering if anyone has ever tried to replace thooth on that type of material. Is there a replacement wheel available somewhere? I really need help with this and any suggestion will be more than welcome.

Thanks,
PXL_20230606_142257533.jpg
 

wow

NAWCC Member
Jun 24, 2008
7,784
1,798
113
78
Pineville, La. (central La.)
Country
Region
Best solution would be to make a brass one but you may be able to make that one work using JB Weld. You would need to drill a tiny hole where each tooth goes and insert two tiny pins into the holes for strength. Then make a larger piece which covers the two pins out of the JB Weld. After the piece dries(24 hours) it is hard and can be filed to the shape of the original fiberglass. Tedious but it will work.
 

mproulx

Registered User
Jul 8, 2009
26
0
1
65
Montreal, Canada
Country
Region
Best solution would be to make a brass one but you may be able to make that one work using JB Weld. You would need to drill a tiny hole where each tooth goes and insert two tiny pins into the holes for strength. Then make a larger piece which covers the two pins out of the JB Weld. After the piece dries(24 hours) it is hard and can be filed to the shape of the original fiberglass. Tedious but it will work.
Thanks WOW, It could be difficult to drill in the thinkness of 1 mm... Do you think cutting out a dovetail as we normally do when replacing a tooth on a brass wheel but filling the dovetail up with JB Weld and then filling out the 2 teeth, would work?
 

wow

NAWCC Member
Jun 24, 2008
7,784
1,798
113
78
Pineville, La. (central La.)
Country
Region
Thanks WOW, It could be difficult to drill in the thinkness of 1 mm... Do you think cutting out a dovetail as we normally do when replacing a tooth on a brass wheel but filling the dovetail up with JB Weld and then filling out the 2 teeth, would work?
It may but I would be concerned about the JBWeld staying in place. It tends to stick better to metal than other materials. If it is 1mm thick it may be tough to do. Others may have a better idea.
 

mproulx

Registered User
Jul 8, 2009
26
0
1
65
Montreal, Canada
Country
Region
It may but I would be concerned about the JBWeld staying in place. It tends to stick better to metal than other materials. If it is 1mm thick it may be tough to do. Others may have a better idea.
Thanks again wow, I really appreciate the time you took to provide a solution, regards
 

Steve Neul

Registered User
May 11, 2023
331
95
28
68
Country
To me the gear appears to be made from phenolic resin. It's actually depending on the cloth fibers inside of it for strength. I don't believe a repair would last unless there is enough space you could fit another gear in beside it to re-enforce it. I think making a brass replacement gear was the best long term solution.
 

Karl Thies

NAWCC Member
Mar 13, 2018
127
44
28
75
Queens, New York
Country
Region
Phenolic resin wheels were used to stop the transfer of noise from the motor. Brass might prove to be rather noisy. Care must be taken when cleaning these wheels, soaking in ultrasonic will tend to make the resin weak and brittle. This is one time when it is recommended to grease the resin wheel after cleaning. I had one made many years ago for a clock that had great sentimental worth to me. It was over $200 for the one wheel. It would probably be better to look on ebay and find a donor movement and hope that it still had a good phenolic wheel. Seth Thomas Medbury 5e models were very popular and they are not too expensive.
 
Last edited:
  • Like
Reactions: wow

Uhralt

NAWCC Member
Sep 4, 2008
5,839
1,030
113
Country
Region
I agree, noise will be a problem with a brass wheel. A long time ago I replaced a couple of missing teeth with brass. It was very audible when these brass teeth passed the motor pinion. I ended up finding a donor on ebay.

Uhralt
 
  • Like
Reactions: wow

mproulx

Registered User
Jul 8, 2009
26
0
1
65
Montreal, Canada
Country
Region
To me the gear appears to be made from phenolic resin. It's actually depending on the cloth fibers inside of it for strength. I don't believe a repair would last unless there is enough space you could fit another gear in beside it to re-enforce it. I think making a brass replacement gear was the best long term solution.
Thank you very much Steve for your input.
 

mproulx

Registered User
Jul 8, 2009
26
0
1
65
Montreal, Canada
Country
Region
Phenolic resin wheels were used to stop the transfer of noise from the motor. Brass might prove to be rather noisy. Care must be taken when cleaning these wheels, soaking in ultrasonic will tend to make the resin weak and brittle. This is one time when it is recommended to grease the resin wheel after cleaning. I had one made many years ago for a clock that had great sentimental worth to me. It was over $200 for the one wheel. It would probably be better to look on ebay and find a donor movement and hope that it still had a good phenolic wheel. Seth Thomas Medbury 5e models were very popular and they are not too expensive.
Thanks Karl, I'll see if I can find a used movement that still has a good phenolic wheel. It's probably the best thing to do. There's a Seth Thomas Medbury on EBay that entiteled Medbury 5E but the model # on the label inside the back door is Medbury 6E. The movement is different from mine but do you think the phenolic wheel would be the same? Picture attached...
ST Medbury 5E.jpg
 

mproulx

Registered User
Jul 8, 2009
26
0
1
65
Montreal, Canada
Country
Region
I agree, noise will be a problem with a brass wheel. A long time ago I replaced a couple of missing teeth with brass. It was very audible when these brass teeth passed the motor pinion. I ended up finding a donor on ebay.

Uhralt
Thank you Uhralt for your input. When you say donnor on ebay do you mean seller? I've never used ebay
 

Karl Thies

NAWCC Member
Mar 13, 2018
127
44
28
75
Queens, New York
Country
Region
Thanks Karl, I'll see if I can find a used movement that still has a good phenolic wheel. It's probably the best thing to do. There's a Seth Thomas Medbury on EBay that entiteled Medbury 5E but the model # on the label inside the back door is Medbury 6E. The movement is different from mine but do you think the phenolic wheel would be the same? Picture attached... View attachment 765582
I noticed that on ebay, it is mislabeled as a 5e, it is actually a 6e and has a capsule motor with a completely different type of movement, German in origin. You need the same movement type as pictured below.

100_1265.JPG
 

Karl Thies

NAWCC Member
Mar 13, 2018
127
44
28
75
Queens, New York
Country
Region
I have a phenolic wheel that I removed from a 5e Medbury some years ago, you can try to see if you can cut it and epoxy a section of it to the bad part of your wheel. If you are interested, PM me with your address and I will send it to you. Clean the areas to be epoxied with a Q tip dipped in acetone to remove any grease. It may be worth a try if you can't find a donor movement on ebay, or if they have become too expensive.

100_1266.JPG
 

mproulx

Registered User
Jul 8, 2009
26
0
1
65
Montreal, Canada
Country
Region
I have a phenolic wheel that I removed from a 5e Medbury some years ago, you can try to see if you can cut it and epoxy a section of it to the bad part of your wheel. If you are interested, PM me with your address and I will send it to you. Clean the areas to be epoxied with a Q tip dipped in acetone to remove any grease. It may be worth a try if you can't find a donor movement on ebay, or if they have become too expensive.

View attachment 765602
Thank you very much Karl, I'll accept your offer with pleasure. How do I PM you? Never done that before.
 

shutterbug

Moderator
Staff member
NAWCC Member
Oct 19, 2005
50,163
3,303
113
North Carolina
Country
Region
If you search this forum for "dove tail" you'll find some great tutorials on how to replace teeth. In your case, you'll need a similar material, and some good glue that will hold the dovetail in place. The shape of it will do most of the work, so you just need to hold it in position. You'll have to do some file work to match the teeth. Probably the easiest approach would be to identify the material, and then look for something made from the same material to use as the repair piece.
 

mproulx

Registered User
Jul 8, 2009
26
0
1
65
Montreal, Canada
Country
Region
If you search this forum for "dove tail" you'll find some great tutorials on how to replace teeth. In your case, you'll need a similar material, and some good glue that will hold the dovetail in place. The shape of it will do most of the work, so you just need to hold it in position. You'll have to do some file work to match the teeth. Probably the easiest approach would be to identify the material, and then look for something made from the same material to use as the repair piece.
Thanks Shutterbug, I will... In the mean time, Karl Thies is sending me a similar wheel to use for repair. Regards.
 

Uhralt

NAWCC Member
Sep 4, 2008
5,839
1,030
113
Country
Region
Thank you Uhralt for your input. When you say donnor on ebay do you mean seller? I've never used ebay
I meant a donor movement from which you could remove the wheel that you need and use it in your clock.

Uhralt
 
Know Your NAWCC Forums Rules!
RULES & GUIDELINES

NAWCC Forums

Find member

Staff online

Forum statistics

Threads
184,167
Messages
1,608,542
Members
56,057
Latest member
LindaH7948
Encyclopedia Pages
918
Total wiki contributions
3,197
Last edit
Joseph Fahys & Co. by Kent
Top Bottom