Crooked teeth

[HectorLooi]

I just took apart my Russian Navy clock for cleaning and to check why it was so loud. I discovered that the escapement platform had loosened and the meshing of the teeth of the 5th wheel to the pinion of the escape wheel had drifted. This resulted in damage to the 5th wheel.

Can I fix this by filing the teeth with a needle file? I don't know if there are replacement parts available for these clocks.

[oldhippy]

Looks like the contrate wheel. This is a hit or miss situation. You might get away by filing the teeth into shape, but you might also file away some depth, in which case you will need to alter the depth of the wheel, that then might stop the wheel because the depth will be too deep for the teeth that have not been affected. The best solution is to have a new wheel made.  

[watchweasol]

Hi Hector I have seen videos of teeth being straightened up using a tool like a screw driver in the dwell and gently levering the tooth straight. II have done it myself on standard wheel but not a contrate wheel, In the end what have you got to loose if it works and I see no reason why not good, I not you will have to resort to a new wheel, In the end its your choice but I know what I would do     cheers

[nichod]

Contrate wheel.  I learned a new term today!      (So did the Linux spell checker)

I should hang out with you clock guys more often.  My Great Grandparents mantle clock calls to me when I walk past.  It runs.  Probably will never quit as the wife won't let me run it.  Sensitive and light sleeper, she is. 

I should move it out here to the cave, but then I'd have to make a hole.

[rodabod]

Presumably that's just wear and not bent teeth?

[watchweasol]

Hi they are bent , there is a definite cast to the right, a loose platform will put the contrate wheel under strain due to incorrect meshing, Running on the wheel tips causing the slight bend.

[rodabod]

Wow. I didn’t realise that there was enough thrust to bend the teeth. 
 

[HectorLooi]

Thanks everyone. I'll try making a chisel-like tool to known the teeth back into shape 1st. If that doesn't work then I'll try filing. Last resort, I found a seller in Ukraine than has spare movement minus the escapement platform. 

[HectorLooi]

I also didn't believe that there was enough force to bend teeth. But it happened.

I've also seen the brass teeth of an escape wheel wear away hardened steel pallets. Clock repair is similar but so different from watch repair. 

[oldhippy]

If that was wear, they would all look like that, this has been done by force due to the platform being moved while power was still on. Lucky it didn't break the escape wheel pivot.  

[HectorLooi]

Yes. You are right OH. The platform loosened or I forgot to tighten the screws fully after adjusting the platform. 

I noticed the second hand jittering only a few days ago. This is cause by excessive freeplay when the platform moved away.

[oldhippy]

That is escaping a few teeth at a time. A good way of testing platforms to see if you have the correct depth is to test the complete movement in all positions, for at least a minute, that way you know the contrate wheel has made a complete turn, even test it upside down. I always did that with any platform clock, if all works well you know it will be OK and the depth is right. Always remember to check the screws are tight.

[wls1971]

The parts are available for the Russian navy clock yours is marked up as a Smiths clock I presume that it is a copy using the Russian movement ?

If it is Russian the contrate wheels are available:

https://www.ebay.co.uk/itm/VOSTOK-Ersatzteil-FUR-RUSSISCHE-U-Boot-MARINE-SCHIFF-WANDUHR/254374795930?hash=item3b39eb5a9a:g:Cm4AAOSwEX1dkdpk

This would be a cheaper option than having a new one cut.

[HectorLooi]

A friend gave me this clock. I didn't ask him where he got it from. It was a very badly put together frankenclock.

The original hinge of the brass casing was broken. An old cupboard hinge was used as a replacement. I don't think the case belongs to a Smith Enfield either. The hands are also a mismatch. 

The bottom jewel of the escape wheel was also missing. The repairer put a blob of acrylic glue over the jewel seat and reamed a hole for the pivot. Managed to pass it off as an old clock that needed oiling.

I replaced the entire escapement platform as it was probably cheaper than trying to get a repacement jewel.

[HectorLooi]

  On 4/8/2020 at 8:04 AM, wls1971 said:

The parts are available for the Russian navy clock yours is marked up as a Smiths clock I presume that it is a copy using the Russian movement ?

If it is Russian the contrate wheels are available:

https://www.ebay.co.uk/itm/VOSTOK-Ersatzteil-FUR-RUSSISCHE-U-Boot-MARINE-SCHIFF-WANDUHR/254374795930?hash=item3b39eb5a9a:g:Cm4AAOSwEX1dkdpk

This would be a cheaper option than having a new one cut.

Expand  

Thanks for the link. I'll try straightening the teeth 1st. If that doesn't work, I'll get the movement from Ukraine as my going barrel also has worn teeth. 

I don't think my movement is a recent one. There appears to be a lot of wear. When I got the clock, the insides were drenched with a very thick oil. The trapped dirt did a lot of damage to the gear train.

[watchweasol]

Hi Hector you really opened a can of worms with this one wish you all the best with it . It will try your patience.       cheers  

[HectorLooi]

It's just after midnight here in Singapore. 4th day of our lockdown.

I spent the evening straightening the teeth of the contrate wheel. I followed the advice of watchweasol and used a thick bladed screwdriver to wedge between every tooth and nudged them straight. Then filed the teeth a little to make them symmetrical. 

Sorry I didn't take a final photo of the wheel. Didn't have the energy to take apart the clock again. 

Thanks everyone for the help.

[watchweasol]

They dont look too bad with the platform on and TIGHTENED , dont for get to set the depth dont want it to happen again   all the best Hector