A jumphour clock uses discs with numbers round the outside instead of hands. These are covered bay a window used to veiw a section of the discs and read the time. They were popular in the early seventies as a cheap altunative to digital watches.
I decided over the weekend I quite fancied having a go at making one using the cheapy clock mecs we use at school.
So while the dancing was on the telly Sunday night I drew up some plot paths for the case and some designs for the discs.
To keep them nice an light the number disks were printed onto OHP transparencies and glued to the original hands mounting boss, with the hand cut off. The case is laser cut 4mm MDF with a clear acrylic window. The window has a fine line etched accross the center as a datum for reading the time. The hour on or below and the minute on the line give the time.
The finish isn't great , but i'll perfect that if I can find some very thin vineer that I can glue on the outside. Waulnut would be very nice.
Theres a rectangle of white acrylic behind the disks in line with the view window to help the numbers show up a bit better.
I'd like to have a go at building an actual mechanical clock from different coloured translucent acrylic, but i,m having difficulty getting my head round where to start. I think it would probably be easiest to make a pendulum clock powered by weights. I've only got as far so far of finding out that a pendulum of around 300mm swings once a second and made a few rough sketches of the shaft within shaft neede for the hands. Not sure when or if I'll get much further with it. But I'tll be here if I do.
I decided over the weekend I quite fancied having a go at making one using the cheapy clock mecs we use at school.
So while the dancing was on the telly Sunday night I drew up some plot paths for the case and some designs for the discs.
To keep them nice an light the number disks were printed onto OHP transparencies and glued to the original hands mounting boss, with the hand cut off. The case is laser cut 4mm MDF with a clear acrylic window. The window has a fine line etched accross the center as a datum for reading the time. The hour on or below and the minute on the line give the time.
The finish isn't great , but i'll perfect that if I can find some very thin vineer that I can glue on the outside. Waulnut would be very nice.
Theres a rectangle of white acrylic behind the disks in line with the view window to help the numbers show up a bit better.
I'd like to have a go at building an actual mechanical clock from different coloured translucent acrylic, but i,m having difficulty getting my head round where to start. I think it would probably be easiest to make a pendulum clock powered by weights. I've only got as far so far of finding out that a pendulum of around 300mm swings once a second and made a few rough sketches of the shaft within shaft neede for the hands. Not sure when or if I'll get much further with it. But I'tll be here if I do.
And a right pain in the backside they carn be too. 
