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Gina

Advanced Members
  • Content count

    29,018
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About Gina

  • Rank
    Supernova
  • Birthday 21/07/42

Contact Methods

  • Website URL
    http://ginad.uk (currently not available)

Profile Information

  • Gender
    Female
  • Interests
    Astrophotography, Photography, Electronics, Computer Hardware and Software (Programming)
  • Location
    East Devon, UK
  1. Longcase Pendulum Clock

    I might have abandoned this project as not being worthwhile in view of the amount of work required to get it to work but for two reasons - several of my friends are very interested in this project and also that I don't like to just give up
  2. Longcase Pendulum Clock

    Having found that the pendulum won't synchronise unless the period is already very close to correct, it seems that some sort of period adjustment is required anyway. In vintage clocks this is usually a thumbscrew on the pendulum bob to move it up or down. Adjusting the other end is equally valid. This could be manual or servo controlled (automatic) and I like a clock that looks after itself Now since it seems that a servo controlled period could do the whole job of timekeeping it seems unnecessary to use magnetic synchronisation as well. The above approach differs from my previous idea which was to manually adjust the period until close enough to synchronise by mechanical levers etc. from the auto-winder.
  3. Longcase Pendulum Clock

    Thinking about pendulum timing control servo system, it might be worth doing this in two stages viz. coarse and fine :- Measure the cycle time and adjust to make it 2s. Compare pendulum phase with RTC phase and fine adjust to produce synchronism. All this can be done with the Arduino I'm already using to drive the auto-winding system. The mechanism for controlling the pendulum length could be a threaded rod driven by a stepper motor.
  4. Longcase Pendulum Clock

    Been looking again at slave clocks and those with pendulums seem to use solenoids mostly. In my clock design I have been using levers and a spring running off the auto-winding mechanism which is timed from a Real Time Clock module. Magnetic drive to the bottom of the pendulum might be better. Another possibility I was trying before was to vary the effective pendulum length by lifting the steel spring support while still holding it in the gap. This shortens the pendulum and reduces it's swing time. I could measure the swing time and control the lift with a servo system until the swing time was exactly 2s. I have worked with servo systems in the distant past and used to know all the maths involved including damping coefficients I have a horrible feeling that I might be past that now! What I don't want is an unstable system that deviates more and more from correct timing Looking back at where I got to before, I see I didn't even get the clock to run continuously without any timekeeping control so on a practical level (when I get back to it) I shall need to produce a decent escape wheel and get everything set up for a running clock.
  5. Longcase Pendulum Clock

    Since posting last I have made good progress on the "GinaRep Mini" 3D printer but most projects are on hold until I shake off a heavy cold. Also, this project has to take a back seat to astro projects and I need a calendar more than another clock - the Moon Dial Clock is working fine. OTOH while I'm resting with this cold there is no reason why I shouldn't think about this project and after a considerable break I may have some new ideas :D. I have one serious problem with this pendulum clock - the pendulum and escapement. I can't expect to make a perfect time-keeper with just a weight driven pendulum clock - even the most expert clock maker has not achieved this, so synchronisation to a true source of perfect time is what I have been trying to do. So far I have not achieved this. I know I need to make a better escape wheel but also I need to sort out a workable way of driving the pendulum from my time source. Slave timepieces have been made in the past so I see no reason why I shouldn't be able to do the same.
  6. are the pictures real?

    The human eye can see Ha but it is highly attenuated. I've looked through an Ha filter and it shows a deep red view. The Ha emissions are just not strong enough to be seen by the eye through a telescope.
  7. are the pictures real?

    I think that's why many beginner astronomers are disappointed. They see all these superb stacked and highly processed images and think that's what can be seen through a telescope but it isn't.
  8. Plate solving

    One reason I use KStars is that everything is included on one piece of software.
  9. I'm just relaxing, playing some very old records that I haven't played for decades As a scientist and engineer I can't explain why analogue reproduction sounds smoother than digital but it does I can only think that the human ear/brain combination is more finely tuned than can be explained by science. I've also ordered a couple of vinyl records in the hope that these will be free from clicks and pops that my old records have and that no digital processing has been used in their production.
  10. I've picked up another cold from somewhere and feeling far from inclined to do much so I won't be Worst of it is a sore throat together with cough and muzzy head. I shall just have to take it easy - as long as I sit quietly I don't feel too bad. Until I feel a bit better all projects are on hold
  11. What did the postman bring

    I had a 28mm f2.8 lens delivered today That will go on my dual widefield rig
  12. Trying to compensate for something

    Just glad I'm an imager - can't manage wobbly heights anymore! Size isn't needed for imaging
  13. Happy Autumnal Equinox

    Cloudy here!
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