Since I always felt that the SP7 clock always had the Art Deco vibes... I decided while I'm making the new base that the Regulated Pendulum Driver will sit in, I'll make it on the Art Deco side, as will as the clock face and new clock hands. I also found a way to never have the loose clock hands again. But time will tell.
Steve I had an idea over the weekend while I was doing some plumbing. lol. I thought how over a short period of time the minute hand in our hands always become loose and you have to wind up reprinting them tighter again and again. And then I got the idea of why not make the end of the two gears that hold the minute hand and the hour hand like the end of a spicket that looks like a small gear at the end of it and you attach the handle that also has the matching gear inside that to match the shaft of the spicket. So the two gears per minute had an hour hand would have gears on it and then the hour hand and minute hand have the matching cut out of the gears to push on nice and tight. And I think having them tha…
I have been looking for a better mechanism for the hands, especially the hour hand. Some traditional designs use a square post instead of a full spline. Or I might try a set screw from the tail end.
Hi Steve... Its Bill Roman.... I have a question about the Moon Phase Clock. What would you have to change on the gears to only run the clock by the pendulum. No weight shell. Just like the (Elecromagnetic Desk Clock). I can make Moon Phase clock and some of your other clocks run without weight shells. And you would be able to set the bob in a matter of minutes and have accuracy of 1 to 2 seconds a month. I can't show the prototype of the driver board yet since Im still testing adding and removing parts. I can tell you that, and I will explain later, that I figured out the main problem with the Electromagnetic Desk Clock with is one of my favorites and has been the biggest pain in my ass that I was not going to let it win me over. lol. I've spent o…
Sorry Steve I've been so busy I will be showing you everything for the electromagnetic clock very soon and also the boards and what has to be changed in order for this to work. Right now I'm on revision 4 of the board but this will be the final board. I'm just waiting for them to be delivered from JLCPCB in China. I'm supposed to get them this week sometime. But previous boards that I've been using have been working great I just wanted to change a few more things on it and make things more sensitive using trimmers instead of resistors especially for the coil. And it does have a compensated oscillator and the data sheet says it's accurate to
<2 PPM. Talk to you soon.....
I am really enjoying the SP14 Moon Phase clock that I built from Steve's plans. It is far more accurate than I would have imagined; until I opened the windows this spring and heated up the room. Now the clock runs about 1 min per day slower. Easily adjusted for, but as an engineering curiousity does anyone know of a material I could try that has a lower thermal coefficient of expansion to see if I can minimize this sensitivity? All pendulumn parts are currently eSUN PLA+.
Great question. Google "coefficient of thermal expansion" to get a list of changes per degree of temperature change. Plastic is typically about 3x worse than brass or steel. But, as you have noticed, modern houses with heating and air conditioning really only change temperature by a few degrees twice a year.
Two of my oldest clocks, SP2 and SP3, used carbon fiber rods which should have very low thermal expansion. It added to the bill of materials and added extra assembly steps. The clock wasn't really any more accurate so I switched back to simple printed pendulum rods. This works well enough as long as the temperature changes are minimal.
Maybe the "carbon fiber" archery arrows I used were not actual carbon fiber, but closer to plastic with a few bits of fiber embedded. I never actually tested their expansion rate. There is another material called invar that is very close to zero expansion. It is expensive.
Other options include taking advantage of the differences in expansion between brass and steel to build a gridiron pendulum rod. Or use plastic and steel. It would add a bit of complexity.
Looks good. I have been thinking about adding a set screw to the tail of the hour hand to secure it in place.