Problem with clicks
  • Got a bit of an ongoing issue with the winder mechanism of my clock - I'm trying to work out a way to mitigate it without further damaging it - but I see I may have to rebuild it at some point within the next year.

    Generally, it's very well behaved - but occasionally the 'clicks' slip on the winding barrel. When this happens, the weight pulls down hard till they clicks re-engage with the winding barrel. This is slowly damanging the ratchet wheel on the winding barrel as the teeth are getting stripped (slowly) - obviously the more this goes on, the more damaged the teeth will be and the more frequently the clicks will slip.

    I'm not sure what the underlying problem is. My clicks are fairly loose so have quite abit of play - I thought this would be better than being a bit tighter as they'd have more oppurtunity to 'fall' into the ratchet. I could file down the clicks a bit more - but if I file on down so it falls more easily into the ratchet, then the other clicks will be harder to fit, surely? Self-defeating.

    Any ideas I can try before the barrel assembly need to be replaced?

    Dave
  • I guess easiest way would be to glue a second strip to clicks to bring closer to center or re make ratchet slightly larger.

  • I haven't had that problem with my Septimus but I have had the same problem with a clock that I built from scratch that used similar clicks and ratchet. When I first built it it slipped a lot and that turned out to be unequal sized clicks, so you are right that shortening one will make it harder for the others to fall into place (that was my problem). I took my clicks off and lined them up by putting a suitable drill through their pivot holes. I then filed them to the same length and made sure that the corner that enters the ratchet matched the shape of the ratchet. I haven't had much trouble since doing that, although I am careful to make sure that a click is fully seated when I wind the clock as that's when it can still jump a ratchet.

    When it was slipping it behaved much as you described. My bottle of water fell rapidly until one click engaged with the ratchet. One time it stopped so violently when a click engaged that it broke the string holding the bottle and we had water all up the wall and over the floor. Luckily I managed to clear up well enough to still have my clock on the wall!
  • I know the feeling of a run away drive weight and then when it catches it sends a shudder through the clock like a bash with a sledge hammer, may raise the pulse but ultimately does more damage than good.

    The clicks on the Septimus are gravity clicks, so most of the time the only connecting click will be the upper one, and occasionally 2 with the bottom one not connecting at all.

    Is the problem more that the click does not fall into the ratchet?

    If that is the case then that means it is not free moving, as the screws are not exactly precision manufactured, it could be the head is slightly too big and causing friction in the click screw head recess, a whip round the head with a file will solve this problem. Also it could be that the click/drive wheel connecting surfaces are not smooth and therefore a bit "sticky", apart from sanding a small rub on of candle wax will solve this.

    Is the problem that they fall into the ratchet but then under load spring back out?

    This has to do with the geometry of the clicks but as I only offer the Septimus either as a complete kit or DXF for CNCing, this should not really occur, as the geometry is tried and tested and works out of the box.

    This is how it should look:-
    image

    Of course one method is just to first release the weight when you are sure that at least one click has connected, pull on the wonder string with one hand and hold the drive weight with the other and first let go when you see that a click has connected.

    Anyhow if you can not solve the problem with your now damaged clicks and wheel, if you pay the shipping I will send you new clicks and wheel.

    Click.JPG
    500 x 389 - 12K
  • Oh - thanks for getting back so soon - and apologies for not checking recently. I think the fundamental problem was as Petec described. I should have put clicks together and sanded the edges together to keep them utterly identical. The problem with the ratchet seems to be that the torque on the cog pushes the ratchet out it's hole as you describe. Mostly it only stops slipping when two are 'engaged'. Having said that, once it is 'engaged' the clock generally doesn't slip - I've only heard it happen during normal operation twice in 18 months. The problem is only really a problem when releasing the winding string.
  • After almost a year of trouble-free operation, I'm now starting to experience this self-same problem with my Sextus. In the past month I've managed to smash the weight shell twice as it crashed to the ground.
    Today I spent some time examining the mechanism and made the following observations......
    1) The incidents have caused the woodscrews holding the clicks to expand their holes, so I must do some work in the near future to keep the clicks held in place. Maybe 3mm nuts and bolts may be better? These screws are transmitting the full force of the drive weight.
    2) I removed the escapement and, with a small weight on the drive, watched the clicks going round. Sometimes only the end of the tip engaged with the ratchet, and there is a huge force being transmitted through this tip. I wonder if it would help to inlay some brass rod into the clicks to increase the weight and make the engagement more positive?
    3) I did notice that one of the teeth on my ratchet had been slightly damaged, but I've dressed it a little and set the clock going with fingers crossed.
  • It seems that the weakest point of the Sextus is its clicks, or rather the fact that there is a maximum of 2 clicks engaging and most of the time just the one, this obviously puts too much stress and strain on them. The solution of course is to have all three engage at the same time and spread the load, I have already done some experimenting and as soon as the Christmas rush is over I will be publishing the results here and sending out new clicks free of charge for those who want them.
  • That sounds like an excellent idea. Thanks, Dave.
  • How did the testing go Dave? I'm interested to hear what your solution might be.

    I should point out that I haven't had any issues, but I haven't completed the clock yet, so it's too early to tell. I've been thinking about the clicks though, as it does seem to be the point with the greatest potential for danger.

    I considered shortening or removing the back (non-engaging) end of the clicks, and then putting an elastic band around all three. That would in theory keep all three engaged, while still allowing them to ratchet when the weight is lifted. Has anybody tried something like that?

    Actually, an invisible way to deal with it might be to put a tiny screw in the back of each click, in the fat part. Then a small elastic band from the screw to the spacer (part 1A) in the back, one elastic for each click, would pull them in as required.

    Bolts and nuts instead of screws might also help a little (as Paul suggested above), especially if the stress is pulling hard and loosening the holes in which the screws sit. Is this a potential issue too?
  • I have only modified the Sextus clicks, the problem there was the fact that the drive weight is roughly 2.7 Kg which caused problems when only one click engaged, the Septimus has a max. of 1Kg of drive weight and can tick along nicely on 700-800 g, so it should present no problems.
    But that aside I will also take a look at using a similar solution to the Sextus in the future.
  • Thanks Dave. That does sound reassuring, given that the Septimus only has one third of the weight (or less) compared to the Sextus.

    I still think I'll have a go at making sure all three clicks engage, even with the lower weight. I'm now thinking of using tiny springs behind the clicks, where they will be out of sight but still do the job. I might not get to it for a while, but I'll take some photos if it works out.