Accutron center wheel loose--how to tighten??

[LittleWatchShop]

This 218 Accutron center wheel (which functions like a cannon pinion) is loose resulting losing time due to slipping.

Not sure if there is a way to tighten it.

Funny thing, I had a donor so I stole the center wheel only to find that it was shorter!  Yes, the donor had no date, but the fixing watch is day-date.

 

[nickelsilver]

If you pop out the pinion and flip the wheel over it will often increase the friction. Should get it to last a few more decades.

[LittleWatchShop]

5 minutes ago, nickelsilver said:

If you pop out the pinion and flip the wheel over it will often increase the friction. Should get it to last a few more decades.

Brilliant!

[RichardHarris123]

26 minutes ago, nickelsilver said:

If you pop out the pinion and flip the wheel over it will often increase the friction. Should get it to last a few more decades.

How does that work?   Not questioning your advice but curious to the mechanics behind it  

[LittleWatchShop]

8 minutes ago, RichardHarris123 said:

How does that work?   Not questioning your advice but curious to the mechanics behind it  

It is something to ponder.  But...it works!  I just did it.  My guess is that there is a wear pattern established over time that is asymmetrical with respect to the post.  Flipping the wheel establishes a new friction interface.  It definitely increased the friction when I did it.

These types of "slip" systems I have seen a few times on other watches, so this is a good method to have in my back pocket!

[VWatchie]

7 hours ago, RichardHarris123 said:

How does that work?   Not questioning your advice but curious to the mechanics behind it

Yes, I wonder too, if we're curious about the same thing. That is, how do you remove (pop out) and reattach (pop in) the cannon pinion from the wheel?

[Neverenoughwatches]

12 minutes ago, VWatchie said:

Yes, I wonder too, if we're curious about the same thing. That is, how do you remove (pop out) and reattach (pop in) the cannon pinion from the wheel?

The wear is on the underside of the wheel, flipping it over the pinion leaves grip a larger surface area of that side of the wheel. 

15 minutes ago, VWatchie said:

Yes, I wonder too, if we're curious about the same thing. That is, how do you remove (pop out) and reattach (pop in) the cannon pinion from the wheel?

The two wheel arms will give up just enough space for pinion to pop in and out.

[JohnR725]

unfortunately for this particular watch that is a standard problem. One of things that would happen is the lubrication on the tube that the wheel goes on would go bad to get like a rust. So locking that in place the watch would continue to drive with the wheel frozen to its tube but the gear free to rotate.. Then yes the standard practice is to flip it over and most of the time that works.

so classically on a 218 watch the description is the second hand turns but the rest of the hands do not. Yes unfortunately it's a very classic problem I would take a different lubrication other than what was recommended.

 

 

[VWatchie]

10 hours ago, Neverenoughwatches said:

The two wheel arms will give up just enough space for pinion to pop in and out.

OK, didn't realise it would be that "easy" (the arms look so rigid), thanks! It's a really good tip because those cannon pinions with driving wheels can be hard to come by and as John mentions it seems to be a rather common problem.

[nickelsilver]

2 hours ago, JohnR725 said:

 

so classically on a 218 watch the description is the second hand turns but the rest of the hands do not. Yes unfortunately it's a very classic problem I would take a different lubrication other than what was recommended.

 

 

Yes, on an Accutron the power for the train is actually generated at the escapement, so counter-intuitively that tiny delicate index wheel generates a lot of torque by the time you get to the hands. This is why you see Accutrons still running after decades of no oil, but when you get them apart, you see pivots almost completely worn away and such.

[TimelessTech]

It's an extremely common issue, make sure to add a touch of HP 1300 grease to prevent wear or you'll have the same issue not too long from now. Or, hand setting may be really difficult.