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Safe separation of wheels


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Hello,

I’m currently working on a vintage Cortébert 677S movement. During strip down I came across a wheel pivot tightly friction fitted through the train bridge to another on the underside. It reminded me of some Smiths double wheel assemblies but obviously these are supposed to be separated to clean the jewel holes and lubricate. I’m sure given the right amount of pressure they’ll separate. I’m guessing the friction fitting is similar to a centre wheel through a canon pinion. Does anyone have any advice on tackling this safely without risking damage to any of the components? Photos of issue shown.

Thanks!

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When I read your subject title I thought this was going to be something to do with social distancing!!!  :D

 

The wheel on the top of the plate (which drives the center seconds pinion) is a friction fit onto an extended pinion that comes through the plate, a bit like a sub second pinion goes through the main plate.

There is a specific Presto style remover (mine is Bergeon 30638/3) for removing this wheel but it can be done with levers or even razor blades. The key thing is to ensure that the wheel is lifted vertically so that there is absolutely no bending force on the pinion as it is very brittle and easy to break, otherwise it should be relatively easy to remove.

Reassembly is also easy, especially if you have a staking set.

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 I agree with Marc use a presto tool specific for this job. Looking at your pics measure before and lift the wheel from the underside (would be best if poss) so as not to distort the other wheel. The key to this job is a very straight lift. Also when re-stalling a straight push putting the wheels to the same positions on the arbour . 

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Thanks for all your quick responses.

Nucejoe, I’m just concerned that by not separating, I’m unable to easily lubricate the jewel holes after cleaning. However, I don’t have a presto tool (I have an old Star No.230 tool I use instead). Maybe an excuse to buy the required tool though!

Thanks!


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9 minutes ago, Nucejoe said:

With all due respect to both gentleman above.I just clean in place, these independently driven minute wheels and save yourself a headache. Regards

Tempting, I  must admit Joe especially if you do not have the correct tools. However checking to see if the pivot is scored will not be possible so I would remove. 

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On 4/1/2020 at 9:49 AM, AdamC said:

Maybe an excuse to buy the required tool though!

If you decide to buy the presto type tool then be aware there are 2 variants - one for 5 spokes and one for 6

https://www.cousinsuk.com/category/train-wheel-removing-tools

They are quite expensive if you buy new. I got mine second hand, but before I had them I did this successfully with a pair of knife blades inserted under the hub of the wheel.

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Thanks for sharing your thoughts Stuart. I went ahead and bought the 5 spokes version from Cousins based on Marc’s suggestion earlier in this thread. What I’m saving on not going out at weekends has paid for that! Hopefully it will arrive today/tomorrow and I’ll look forward to giving it a go. Will also be a useful tool to add to my slowly growing arsenal.

Cheers!


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  • 2 weeks later...

Just to complete this post, I'm pleased to say that the Bergeon Presto 30638-3 tool I bought worked a treat (photos to illustrate). The movement has now been cleaned, lubricated, and is in working order. I particularly found the BHI paper on the 'Practical lubrication of clocks and watches' interesting and have decided to swap my Moebius D5 oil for Moebius HP 1300 synthetic.

Thanks to everybody that contributed. oil.20200403_225709952_iOS.thumb.jpg.0923e91745364eab9b84dac15951fbd2.jpg

 

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Edited by AdamC
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