Zenith 2552 pc movment cannon pinon slipage.

[Hirst]

Hello WRT posters.

I'm still relatively new to this hobby so advice from this forum has been valuable.  I've only restored about a dozen vintage watches over about a six month span.  I'm working on this Zenith Auto Sport.  I purchased it knowing it had a issue with the stem pulling out.  I discovered a broken Jumper in the keyless works and replaced it.  I have the movement regulated to less  that 10 sec / day but the hands don't keep time.They do move some, but fall behind rapidly.  I can move the hands in the winding position just with a peg wood and feel no resistance.  I believe the cannon pinon is required to have a slip fit but provide enough friction to drive the hands and in this case the calendar mechanism.  I do have two types of tools for tightening.  How much friction is the correct amount?  How does one judge this? I feel no friction at all when I'm setting the time.  I have two types of pinion adjustment tools.  I have ruined one pinion on another project using the Bergeon pliers,  So I'm a pit hesitant.  I'm thinking I should mike the OD of the center arbor,  then have a mandrel at that dimension to prevent crushing the pinon. I also notice plenty of slop in the hour wheel as it fits around the cannon pinion.  Finally,  is  cannon pinion wear  a common problem with older watch movements?  Great looking and nicely made watches in my opinion!

 

Thanks

Hirst

[oldhippy]

As its a sweep second cannon pinion it is hollow, I used to put a Broach one the fits tight through the cannon pinon and with a pair of nippers pinch it lightly to tighten, Use that nice bergeon tool that is what I mean by nippers. It is a trial and error, a little each time as you are just starting out, just make sure it is't to tight that it strips teeth off

[mikepilk]

Wow, a nice fancy tool ! 

I've just had to fix a Citizen which had no friction - you could push the hands round.

Lacking the nice tooI, I use a sharp punch (the centring tool in my staking set) . As mentioned, put a bit of brass wire or broach in to stop it crushing.

It's a very fine adjustment, took me several goes. You will know when it's right by the feel - a slight, smooth friction. 

If you overdo it, don't use a broach to open it out, as it will cut away the metal. A bit of tapered metal (I use an oiler) can be pushed in to open it out a bit. 

[Nucejoe]

11 hours ago, oldhippy said:

 a little each time as you are just starting out.

Thats the key to success in this case, you lower the risk of overtightening this way.

[Hirst]

Thanks for the good advice.  I’ll attempt this in small increments until I get it right.  Q.  Is it correct practice to apply some oil between the cannon pinion and arbor?  It would reduce the needed friction as Slipping is only required when setting time.

[anilv]

One thing to note, the 'dent' in the cannon pinion should be at right angles to the tube. I have had watches where it was pinched at an angle and the canon pinion would ride up on the centre wheel when the hands were set.

Anilv

[Nucejoe]

2 hours ago, Hirst said:

 Is it correct practice to apply some oil between the cannon pinion and arbor?  It would reduce the needed friction as Slipping is only required when setting time.

Grease not oil, you should give it a rinse after tightening, dry and grease.

Good luck

[Klassiker]

Why not oil? Grease or a thick oil would both be OK, I think. Happy to be corrected though. It definitely needs some sort of lubrication, to minimise wear.

[mikepilk]

I use a small amount of oil, D5, but grease is OK

[Nucejoe]

1 hour ago, Klassiker said:

Why not oil? Grease or a thick oil would both be OK, I think. Happy to be corrected though. It definitely needs some sort of lubrication, to minimise wear.

I don't know how thick D5 is, if it does the job so shall it be done. 

Regs 

[mikepilk]

1 hour ago, Nucejoe said:

I don't know how thick D5 is, if it does the job so shall it be done. 

Regs 

All the service sheets I've seen show either thick oil or grease on the pinion arbor.  D5 is 1200 viscosity. Or the synthetic equivalent is 9104 (HP 1300). But only a small amount

[Hirst]

Well, I have to thank you all for the good advice.  As mentioned I did split a cannon on my first attempt using the Bergeon tool.  On a different and not so valuable project.  The center arbor measured 0.69mm with my caliper.  I turned mandrel  out of stainless on my lathe to 0.68mm.  Yep 1/100th mm smaller.  I decided to notch out the tool as shown in a post.  Slightly smaller than the OD of the cannon pinion at 0.92.  After a few delicate crimps I finally got the pinon to grab with friction on my mandrel.  This guy was very tight and was not going down on the arbor.  A bit of grease and a more convincing push with a staking tool did the trick.  Yes is did remove the adjacent wheel.  What a surprise.. Perfect friction.  A challenge for sure.

Thanks again!

Hirst.