Older Helbros With No Identifying Model Number?

[Gary]

Upon disassembling I found the mainspring to be broken. I don't know what size to order. I think the plate states AS 984? 

Will I be able to order one based on just the movement...remember I am new to this horology addiction.

 

Thanks in advance!

 

[Vich]

Hello Gary,

If you go on the Ranfft.de site and search for AS 984 you will get the full description of your movement.

The Mainspring is described as ZFL 389 1.70 x 9.0 x 0.10 x 290mm.

Hope that helps- perhaps a trace in Cousins might find a generic to match or even a Helbros part.

Cheers,

Vic

[Vich]

Cousins have a mainspring Ref GR4879 for £7.30 that is classed by them as your requisite mainspring. The specs do not completely match the Ranfft description but it is being sold as an exact match to your movement.

Cheers,

Vic

[Vich]

Sorry that should have been ZF1 389

 

Vic

[Gary]

Vic,

Thanks! I found the one on Cousins...(I am in the US) but I am going to use the specs on Ranft to order one. I will also attempt to measure the one that was in it to see if it is a close match. Although it was in 3-4 pieces when opening the barrel.

 

Thank you again!

[Vich]

I don't think the extra 10 Mil will make much difference to the working as long as the other specs are the same.  One of the others will correct me if I am wrong but the Barrel size is the same so it should work fine If that is the only size you can source..

 

Good luck,

 

Vic

Edited July 23, 2015 by Vich

[Gary]

The one that was in it...(and I went back to measure basded on Mark's video) is 1.40x.09x.290. Is it sage to assume the incorrect one was placed in there?

[Vich]

Hello Gary,

 

Well as both Ranfft and Cousins agreed on everything except the length I would think on the balance of probability that someone has put the wrong spring in the barrel. 

If you can find another supplier for the mainspring of the AS 984 and see what they come up with that could put your mind at rest.  However, whereas the length may not be as critical I think that the 1.4 instead of 1.7 could indeed make a difference.

 

Cheers,

 

Vic

[Gary]

Vich,

Or anyone that may be able to answer. Thank you you for the assistance on this but I have another question . Ranftt list four numbers as a size 1.70 x 9.0x .10x 290mm.

I understand the 1.70 and the 290 and I think the .10 is the thickness but what is the 9.0?

Thank you again!

Gary

[Gary]

Vich,

Or anyone that may be able to answer. Thank you you for the assistance on this but I have another question . Ranftt list four numbers as a size 1.70 x 9.0x .10x 290mm.

I understand the 1.70 and the 290 and I think the .10 is the thickness but what is the 9.0?

Thank you again!

Gary

I'm assuming the "9.0" is the inner diameter of the barrel?

[Geo]

Correct Gary.