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Clock enthusiasts?
richard thomas - 29/6/12 at 12:16 PM

Can anyone advise?

I have a task where I have to mount a clock mechanism to a beautiful wooden 2 blade propellor. Mechanism behind the prop hub with hands on the front....

I have looked online for movements, and even dismantled a cheap clock, but am struggling to find a movement with sufficient spindle length to fit through the thickness of the prop hub (47mm thick)

Does anyone know how to lengthen spindles, or where I can get a long spindle movement.

I expect to mount quite long hads to it so I think I need a high torque motor.....

Cheers, Rich.


gottabedone - 29/6/12 at 12:41 PM

Don't know anything about clocks but try a simple rigid coupling - you may need to file a flat on the spindle for the grub screw

Steve


maccmike - 29/6/12 at 01:02 PM

quite a long spindle that. Might be easier to recess the movement into the hub. picys once done please


HowardB - 29/6/12 at 01:14 PM

1,. agree with above, recess the movement, or use a small movement

2,. balance the hands so the movement is only dealing with inertia not moment.

even the very locost movements will swing 12" hands with ease if they are balanced and very light

hth


theprisioner - 29/6/12 at 01:16 PM

I have done a bit of restoration of clocks and I have been building one for ages. I use meadsows and passmore


http://www.medmaw.com/cgi-bin/medmaw/medmaw.cgi

Search under either movemennts and kits or hands

The torque thing may not be as relevant as you think, the average clock mechanism has a high torque as it is geared down so much in the first place. The best thing is if you have large hands make them of lighter material and put a spine behind them or even better a crease.


richard thomas - 29/6/12 at 03:38 PM

I have a centre hole of 1 7/8", anyone know of a round movement that might fit in...?


richard thomas - 29/6/12 at 04:04 PM

How do you balance them?

quote:
Originally posted by HowardB
1,. agree with above, recess the movement, or use a small movement

2,. balance the hands so the movement is only dealing with inertia not moment.

even the very locost movements will swing 12" hands with ease if they are balanced and very light

hth



DIY Si - 30/6/12 at 11:01 AM

They're the hands that usually have a long thin pointy end, and a wider shorter opposing end to balance the weight, a bit like these ones. The idea is they have no moment about the pivot.




TheGiantTribble - 30/6/12 at 01:17 PM

Mmmmm I wonder if them hands (especially S8) could be used on a set of car gauges