Centre Wheel Cam

[RogerH]

I've worked on a few mantle clocks lately, all have been very dirty and greasy and in need of a good strip down and clean. One area I'm uncertain about is the centre wheel and the cam gear that fits on the other side of the plate (apologies for incorrect names!)

I've a couple of books and none of them are very clear on the best approach to remove and replace. One book even says to never touch it and leave it alone....which isn't ideal if you want to thoroughly clean the plates.

Is there a best practice for this? I currently use two slightly bent tipped screwdrivers to lever off and a small long box spanner to push back on....so far with no ill effects but it just doesn't feel right. Any thoughts?

I do make a note of position to ensure when it goes back on the strike is at the correct point for the minute hand so it strikes on the hour.

[clockboy]

It could be removed by tapping / pushing the pinion through the cam and gear as it certainly looks friction fitted. However I personally would leave it in situ unless you suspect it needs re-bushing. 

[nickelsilver]

I always remove them. I usually use large levers that are made for such work. You can also tap the arbor through the cam but you want to support the plate near the hole, there are tools called crow's feet that do this.

[oldhippy]

Unless it needs rebushing leave it alone. By tapping it you are more likely to end up bending the shaft and this will cause the movement when chiming or striking to show the hands to be off  the correct position to the dial. 

[RogerH]

Thanks guys,

it's an interesting subject as even the books have mixed views. I think I'll adopt the OH approach as it's a lot of faff and can cause more work than originally needed. So I won't touch it unless I have to!

[oldhippy]

A little tip. If after cleaning you are not sure if all the dirt has been removed put a few drops of oil around it and move it about, if the oil is clean you know it's fine, if dirty it needs more cleaning.