Sligh clock won't keep time

QuestionEdit

We bought a Sligh tall clock in 2000. Model # 0856-1-th, movement 500-0030. I have never been able to get this thing to keep time within an accecptable amount. (We have an antique Vienna regulator that keeps time within a minute a month). I have kept records of every adjustment I make going back a couple of years. The pamphlet that came with the clock states that one full turn of the set screw will change the time one minute/day. I have not found this to be true. We were advised not to let the clock come to a stop, but to stop it if we were not going to be around to wind it. We are human and unable to follow this all the time, not that it seems to make a difference. What gives with this movement? Is it any good? Why does it slow/speed up after stopping? Is there anything I can do to get it to run right? What should I expect out of it? Yes we had it serviced once but it did not matter as far as keeping time goes. Thank you. If you have questions, please ask. Kent

AnswerEdit

Usually timekeeping issues will be traced to the pendulum, not the movement. If you are able to gently remove the pendulum from the leader it hangs from, check 2 things. 1)Is the rating nut seated within the cut-out notch for it on the backside of the disc? 2)Are the vertical rods able to pass through the guide plates on the backside of the decorative lyre? I can't begin to count how many times I've seen a situation where one or more of these rods comes out of the holes in the lowest guide plate when the pendulum is lowered to slow it down, but when it is raised again, they don't quite line up, making further upward movement impossible. As you try to turn the rating nut, it gets harder to turn and eventually will pop out of the cut-out because it can't push the disc upward. In this circumstance, timekeeping accuracy becomes non-existant and you can't tell why because the problem is facing away from you. Also for most grandfathers of this type, one turn of the nut will usually equal @ 1/4 min./day.