Movement for a Mass. Shelf Clock

[macchips4]

I'm thinking of making a Massachusetts shelf clock. I started looking around ebay for weight driven movements that would work, but I'm not sure which would work.
Has anyone used OG clock style movements (time and strike)? Would it be "OK" to use a spring driven movement? even then it is hard to find a weight driven movement with the pendulum/weight in the rear..A banjo type movement seems to have too long of a drop/length pendulum (plus the pendulum is in the front of the movement).......Modify the plans to fit a movement?.......Any thoughts/suggestions?....

 

[Troy Livingston]

Absolutely, get the movement first then modify your plans as required to fit.

While an OG movement may work there are problems. OG weight cords run up to a pulley at the top of the case and the weights travel along the sides of the case. This would be incompatible with your style of case. Most are 30 hour but there are 8 day movements as well. It might be possible to make some modifications to allow the weights to fall in a more appropriate manner but this would also probably require custom cast weights, especially for the 8 day movement. A spring driven American strap movement may have clearance issues as the springs extend out from the side of the movement quite a bit as the clock runs. Springs in barrels would remove this problem.

Your best bet will be to find a movement for a banjo clock. Theses are similar enough in size and design that it should be the easiest to fit to your clock.

Massachusetts shelf clocks were made with both pendulum in front of and behind the movement. I prefer the pendulum in front as it is less sensitive to clearance issues between the pendulum and the case back. A weight rubbing a little on the back of the case is much less trouble than the pendulum bob rubbing.

Ebay will probably be your best source for a movement but if you are anywhere near Lancaster, PA the NAWCC National is next week and I believe they are opening the mart up to non members for a day.

Troy