Spring drive
  • Hello to all ,
    I think that somewhere I read that someone has already made this mod to the SEXTUS and as I am now able to build another SEXTUS ". I should point out that the 1st one was also my first clock of any kind and built by me to try out my home built CNC machine and to find out what is involved in clock building ". I am trying to find out what size/type of Spring is required to run the clock, as I think it will look better. Ps the 1st clock runs just fine but as ever needs timing.
  • Andrew Cocker sent me the below description and photos of his spring driven variation of the Sextus.

    1. The spring.

    is not a spring, but a “spring motor” - different in that is requires two drums (rather than one). The one that I am currently using is an SDP/SI
    part, number A3X51-20010 which has 5.5lb/in spring torque. With better workmanship, I feel that a A3X51-20009 (which has 3.87lb/in of torque) would be possible - for a while, mine was running happily on such a spring but I think humidity changes cause movement in the wood which, in turn, seems to up the internal friction of the clock.

    2. The arrangement.

    The attached photos illustrate the setup of the spring motor - with its two drums. The spring is fully unwound in this shot. I have also shown a picture of the slightly modified winding ratchets - they are now spring loaded to provide better certainty of engagement as the spring under load can get away from you quite badly.

    Happy to take any other questions that might arise.
    480 x 640 - 87K
    480 x 640 - 68K
  • David
    My thanks to you for the information that you have supplied, I will work on the modifications, as now I understand how it's done. Please relay my thanks to Andrew
    Along with other changes to the build, it looks like a very interesting few weeks to come.will keep you updated on the progress .
  • Hi Andrew
    You put me on the right track for the " Spring " drive . I have fitted a drive to my clock. It's a single barrel with the Spring No CM3418 supplied by Walsh and sons ltd and fitted into a 45 mm bore.At this time I have no other information to offer up as I need to evaluate the the running times etc
  • Update James!?
    Perhaps the popularity for a Woodentimes " alternate drive kit" is worthy the efforts to discover Dave? Surely this modification could be shared on most your other designs?
  • The spring loaded "keepers" on the ratchets (clicks) is not found in the edge view. Is this coiled on the hidden end of the wire? (under the gear spokes?)
    How / where were these parts sourced?
  • I am about to start work on my Sextus kit, and I am leaning towards a spring drive, as pioneered by Andrew Cocker. Are there any long-term results on reliability, accuracy etc for spring-driven Sexti which members have made?
    I would greatly appreciate learning from your experiences.